U.S. patent application number 10/215662 was filed with the patent office on 2003-03-13 for edge protection.
Invention is credited to Garnett, Paul J., Heffernan, Peter, King, James E., Mayhead, Martin P..
Application Number | 20030051057 10/215662 |
Document ID | / |
Family ID | 27390027 |
Filed Date | 2003-03-13 |
United States Patent
Application |
20030051057 |
Kind Code |
A1 |
Garnett, Paul J. ; et
al. |
March 13, 2003 |
Edge protection
Abstract
A server blade may comprise a processor and a network interface.
The network interface can be configured be connected to a network
remote the server blade. The server blade may be configured to
perform an edge protection function for an entity connected to the
network. The server blade may be further configured as a field
replaceable unit. Optionally, the server blade may further comprise
an enclosure which encloses the processor.
Inventors: |
Garnett, Paul J.; (Surrey,
GB) ; King, James E.; (Surrey, GB) ; Mayhead,
Martin P.; (Berkshire, GB) ; Heffernan, Peter;
(Hampshire, GB) |
Correspondence
Address: |
B. Noel Kivlin
Conley, Rose, & Tayon, P.C.
P.O. Box 398
Austin
TX
78767
US
|
Family ID: |
27390027 |
Appl. No.: |
10/215662 |
Filed: |
August 9, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60311505 |
Aug 10, 2001 |
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60366430 |
Mar 21, 2002 |
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Current U.S.
Class: |
709/249 ;
370/401 |
Current CPC
Class: |
G06F 2221/2141 20130101;
G06F 21/629 20130101; G06F 2221/2149 20130101; H05K 7/1425
20130101; G06F 21/55 20130101; G06F 1/187 20130101; G11B 33/128
20130101; G06F 2221/2137 20130101; G06F 1/183 20130101; G06F 21/31
20130101; G06F 2221/2119 20130101; H04L 63/1416 20130101; H05K
7/1489 20130101; H04L 63/083 20130101 |
Class at
Publication: |
709/249 ;
370/401 |
International
Class: |
G06F 015/16; H04L
012/28; H04L 012/56 |
Claims
What is claimed is
1. A server blade comprising at least one processor and a network
interface configured be connected to a network remote the server
blade, the server blade being configured to perform an edge
protection function for an entity connected to the network, the
server blade being further configured as a field replaceable
unit.
2. The server blade of claim 1, comprising an enclosure which
encloses the at least one processor.
3. The server blade of claim 1, configured removably to be received
in a modular computer system comprising the network, and to control
access between a network external the modular computer system and
the modular computer system.
4. The server blade of claim 3, configured to control a flow of
network traffic between the modular computer system and the
external network.
5. The server blade of claim 3, configured to control a flow of
TCP/IP protocol network traffic.
6. The server blade of claim 5, configured to control a network
flow of hypertext transfer protocol traffic.
7. The server blade of claim 5, configured to control a network
flow of file transfer protocol traffic.
8. The server blade of claim 5, configured to control a network
flow of simple mail transfer protocol traffic.
9. The server blade of claim 1, configured to provide a login
authentication function.
10. The server blade of claim 6, configured to provide the login
authentication function on at least one of a user basis, a client
basis and a session basis.
11. The server blade of claim 1, configured to monitor network
traffic for a predetermined network attack pattern.
12. The server blade of claim 1, configured to store a log of
network traffic activity.
13. The server blade of claim 1, comprising a solid state memory
configured to store operating software for the server blade.
14. The server blade of claim 13, wherein server blade comprises
the record store.
15. The server blade of claim 13, configured to transmit the record
to a remote record store.
16. The server blade of claim 1, configured to report an edge
protection event to a management entity.
17. The server blade of claim 16, configured to compare an edge
protection event to a predetermined set of events to determine
whether to report a detected property to a management entity.
18. The server blade of claim 16, comprising a management
communication interface configured to transmit a report of an edge
protection event to a management entity.
19. The server blade of claim 18, wherein the management
communication interface is distinct from the network interface.
20. The server blade of claim 1, configured as an appliance.
21. The server blade of claim 1, configured as a firewall
blade.
22. A server blade comprising processor means and network interface
means for connecting to a network remote the server blade, the
server blade being for performing an edge protection function for
an entity connected to the network, the server blade being further
configured as a field replaceable unit.
23. A modular computer system comprising: a carrier operable
removably to receive a plurality of computer system modules
therein; a plurality of information processing modules removably
received in the carrier, each module having a communications port
operable to connect to a communications network internal to the
carrier; a switch operable to connect to the internal
communications network to distribute information messages between
the modules and to connect to an external communications network;
and an edge protection module removably received in the carrier and
operable to connect to the internal communications network to
control traffic access between the internal communications network
and the external communications network.
24. The modular computer system of claim 23, wherein the control of
traffic access comprises control of traffic using an internet
protocol.
25. The modular computer system of claim 24, wherein the internet
protocol includes TCP/IP.
26. The modular computer system of claim 21, wherein the control of
traffic access comprises login authentication.
27. The modular computer system of claim 23, wherein the edge
protection module is configured to record an edge protection event
in an event log.
28. The modular computer system of claim 27, further comprising a
service processor operable to perform a service function for the
information processing modules and wherein the edge protection
module is configured to transmit an event log entry to the service
processor.
29. The modular computer system of claim 23, wherein the edge
protection module comprises an enclosure which encloses functional
components of the module.
30. The modular computer system of claim 23, wherein the edge
protection module is configured as an appliance.
31. The modular computer system of claim 23, wherein the edge
protection module is configured as a firewall blade.
32. A modular computer system comprising: carrier means for
removably receiving a plurality of computer system modules therein;
a plurality of information processing modules removably received in
the carrier, each module having communications means for connecting
to a communications network internal to the carrier; switch means
for connecting to the internal communications network for
distributing information messages between the modules and for
connecting to an external communications network; and an edge
protection module removably received in the carrier for connecting
to the internal communications network for controlling traffic
access between the internal communications network and the external
communications network.
Description
[0001] BACKGROUND OF THE INVENTION
[0002] The present invention relates to computer systems, in
particular to edge protection systems for multi-processor systems,
for example multi-processor server systems.
[0003] One application for the present invention relates to high
density computer systems, for example, computer server systems for
telecommunications applications. In telecommunications
applications, it is important to provide high reliability and high
capacity of operation. Various approaches have been taken to
providing such high-performance, high reliability systems.
Typically such systems are designed around providing redundant
resources so that if one component of the system develops a fault,
the system remains operational using the redundant resources. Fault
tolerance can also be achieved, for example, with multiprocessor
systems that provide redundancy through dynamic, e.g.,
software-controlled, task distribution. Protection from damage or
interference from outside sources may typically be provided to
increase the security, reliability and availability of the system
by controlling access through the edges of the system. High density
systems are typically rack mountable, with one or more processor
systems occupying a shelf in the rack. The trend in recent times is
to make the computers with smaller form factors. This means that
more computers can be located in a rack. This has the advantage of
increasing the processing density within the racks, and also the
advantage of reducing the distance between the computer
systems.
[0004] The present invention relates to the provision of edge
protection services in a higher density computer system. This may
include filtering of traffic entering and leaving the computer
system to prevent or impede traffic caused by a security breach
event.
[0005] In situations where a group of individual computer systems
(such as servers) are connected to work co-operably with one
another, providing protection at the edge of such group of
individual elements may substantially boost the operating
reliability, security and availability of the group of computer
systems many times over.
SUMMARY OF THE INVENTION
[0006] A first aspect of the invention may provide a server blade.
The server blade may comprise a processor and a network interface.
The network interface can be configured to be connected to a
network remote to the server blade. The server blade may be
configured to perform an edge protection function for an entity
connected to the network. The server blade may be further
configured as a field replaceable unit. The server blade of this
arrangement may therefore perform a firewall function for a blade
computer system from within the system, thereby providing an
efficient and secure network firewall function. Thus the
operational reliability, security and availability of the computer
system may be enhanced.
[0007] Optionally, the server blade may further comprise an
enclosure which encloses the processor. Thereby the server blade
may be made resilient and handling thereof may be performed with
reduced care and attention and may be performed by an unskilled
worker.
[0008] A further aspect of the invention may provide a modular
computer system. The modular computer system may comprise a carrier
operable removably to receive a plurality of computer system
modules therein and a plurality of information processing modules
removably received in the carrier. Each module may have a
communications port operable to connect to a communications network
internal to the carrier. The modular computer system can also
comprise a switch operable to connect to the internal
communications network to distribute information messages between
the modules and to connect to an external communications network,
and an edge protection module removably received in the carrier.
The edge protection module may be operable to connect to the
internal communications network to control traffic access between
the internal communications network and the external communications
network. This arrangement provides a modular computer system having
a firewall facility integral thereto to enable secure and efficient
operation of the system.
[0009] Further aspects and advantages of the invention will become
apparent from the following description of particular
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Embodiments of the present invention will be described
hereinafter, by way of example only, with reference to the
accompanying drawings in which like reference signs relate to like
elements and in which:
[0011] FIG. 1 is a schematic representation of an architecture of a
multiprocessor system for supporting a web site;
[0012] FIG. 2 is a schematic representation of a racking system
incorporating an example of a carrier in the form of a
rack-mountable shelf according to a first example;
[0013] FIG. 3 is a front view of an example of a carrier in the
form of a shelf of FIG. 2;
[0014] FIG. 4 is a rear view of an example of the shelf of FIG.
2;
[0015] FIGS. 5A, 5B and 5C are schematic perspective views and a
schematic exploded view respectively of an example of an
information processing cartridge for mounting in the shelf of FIG.
2;
[0016] FIG. 5D is a schematic perspective view of an example of an
information processing cartridge for mounting in the shelf of FIG.
2;
[0017] FIG. 6 is a schematic perspective view of an example of a
combined switch and service processor module for mounting in the
shelf of FIG. 2;
[0018] FIG. 7 is a schematic perspective view of an example of a
power supply module for mounting in the shelf of FIG. 2;
[0019] FIGS. 8A, 8B and 8C are a schematic plan view and schematic
perspective views, respectively, of an example of the chassis and
midplane of the shelf of FIG. 2;
[0020] FIG. 8D is a schematic perspective view of a part of a base
member of the shelf of FIG. 2;
[0021] FIGS. 9A, 9B and 9C are schematic front, top and rear views,
respectively, of an example of a midplane of the shelf of FIG.
2;
[0022] FIG. 10 is a schematic cross section view through the shelf
of FIG. 2;
[0023] FIG. 11 is a functional block diagram of an example of an
information processing subsystem for the information processing
cartridge of FIG. 5;
[0024] FIG. 12 is a functional block diagram of an example of an
information processing subsystem for the combined switch and
service processor module of FIG. 6;
[0025] FIG. 13 is a functional block diagram of an example of a
subsystem for the power supply unit of FIG. 7;
[0026] FIG. 14 is a functional block diagram showing the
connectivity between the components of the shelf of FIG. 2;
[0027] FIG. 15 is a functional block diagram showing the external
connectivity of the shelf of FIG. 2;
[0028] FIG. 16 is a schematic representation of a shelf showing the
external connections from the shelf of FIG. 2;
[0029] FIG. 17 is a schematic representation of a rack mounted
system comprising a plurality of such shelves;
[0030] FIG. 18 is a functional block diagram of a further example
of an information processing subsystem for the information
processing cartridge of FIG. 5; and
[0031] FIG. 19 is a functional block diagram of a further example
of an information processing subsystem for the information
processing cartridge of FIG. 5; and
[0032] FIG. 20 is a functional block diagram of another example of
an information processing subsystem for the information processing
cartridge of FIG. 5.
[0033] While the invention is susceptible to various modifications
and alternative forms, specific embodiments are shown by way of
example in the drawings and are herein described in detail. It
should be understood, however, that drawings and detailed
description thereto are not intended to limit the invention to the
particular form disclosed, but on the contrary, the invention is to
cover all modifications, equivalents and alternatives falling
within the spirit and scope of the present invention as defined by
the appended claims.
DESCRIPTION OF PARTICULAR EMBODIMENTS
[0034] Embodiments and examples are described hereafter by way of
example only in the following with reference to the accompanying
drawings.
[0035] Shown in FIG. 1 is an example of an application of a high
capacity multiserver system 1 for implementing a network-connected
web site such as, for example, an airline reservation system on the
World Wide Web.
[0036] As shown in FIG. 1, an external network 3 (e.g., the
Internet) for communicating with a user 5 can be connected to
gateways 7 which can be connected to an entry edge server group 9
implemented by a web farm. The entry edge server group 9 forms an
interface to the external network 3. The entry edge server group 9
can then be connected by switches 11 and a firewall 13 to a web
edge server group 15 that can also be implemented as a web farm as
shown in FIG. 1. The web edge server group 15 can serve to cache
web pages that are readily accessible to users 5 accessing the
system 1 from the external network 3, for example for checking
flight times, etc. The web edge server group can comprise a number
of blade server (BS) shelves and a number of network addressable
storage (NAS) shelves for storing critical data. The web edge
server group 15 can be further connected by a further firewall 17
to a plurality of application servers 19, which can be responsible
for, for example, processing flight reservations. The application
servers 19 can then be connected via a further firewall 21 to
computer systems 23, 25, for example, e-commerce services including
financial services for receiving and processing payment for airline
reservations.
[0037] As will be appreciated, the server system described above
with reference to FIG. 1 is only an example of a possible
application for a multiprocessor server system. Multiprocessor
server systems have many different applications and the present
system is not limited to being applicable for use in only one or a
limited number of such applications, rather multiprocessor server
systems as described herein are operable for use in many different
applications. A non-exhaustive list of such alternative
applications includes: e-commerce web server systems;
telecommunications network server systems; LAN application and file
server systems and remote vehicle control systems.
[0038] With reference to FIG. 2, there is shown a schematic
perspective representation of a rack system 31 as viewed from the
front including left and right front uprights 32 and 33 and left
and right rear uprights 34 and 35. The uprights can be formed with
apertures for receiving shelf fixings (e.g., screws, bolts, clips,
etc., for mounting brackets, slides, rails, etc.).
[0039] Also shown in FIG. 2 is an example of a blade server shelf
41 mounted in the rack system 31. The shelf 41 forms a carrier
configured to carry a plurality of information processing
cartridges 43 located side by side along the shelf.
[0040] The term "shelf" is used herein in a conventional way to
describe a structure that is mountable in rack system 31 and is
configured to carry one or more components to form at least a part
of a rack-mountable system. In the present example, the shelf 41 is
three-dimensional, having a height (H), width (W) and depth (D). In
the present example, one dimension (hereinafter described as the
height, H) is smaller than the other dimensions (hereinafter
described as the depth, D, and the width, W) to facilitate mounting
of the shelf within the rack system 31. It will be appreciated that
although the width and depth are typically constrained by the
dimensions of the racking system for which the shelf is designed,
there is more freedom as regard the height, subject to taking
account of any appropriate standards and packaging
considerations.
[0041] Each of the information processing cartridges contains at
least one processor. Each information processing cartridge in the
present example is operable as a server. In the described examples,
the information processing cartridges are configured as robust
enclosed modules.
[0042] In the example to be described in more detail presently, the
information processing cartridges, when aligned in the carrier
shelf, look like rectangular slabs, or blades. Accordingly, an
information processing cartridge can be described as a blade. The
information processing cartridges 43 comprise information
processing modules enclosed in an enclosure, or housing, so that
the information processing modules have the form of cartridges.
Also, as the information processing cartridges are to operate as
computer servers in the example described in more detail presently,
an information processing cartridge 43 can also be described as a
server blade. Accordingly, in the context of this example, the
terms module, cartridge and blade are used interchangeably.
[0043] The illustrated example of a shelf 41 is configured to carry
sixteen information processing cartridges 43, each of which is
removably mountable in a respective opening 45 in the front of the
shelf, whereby the information processing cartridges can be
inserted into and removed from the front of the shelf 41 without
removing the shelf 41 from the rack system 31.
[0044] In the present example, the shelf 41 comprises a
three-dimensional, generally rectangular, enclosure, or housing, 47
that is suitable for mounting in generic racking systems including
both 4-post and 2-post systems. It can be mounted on fixed rigid
rack mounting cars and/or a simple slide/support system. The
present example is designed for standard 19"-wide racking (1"=5.4
mm) as defined, for example, in the well-known IEC297 and EIA 310
specification standards with height corresponding to the so-called
3U (3 standard unit) height. For mounting such a 3unit in such a
19"-wide racking system, with a depth of, say 25" or 30", the
enclosure can be arranged with a height of up to about 130.5 mm, a
width of up to about 445 mm and a depth, including all hardware and
fascias, but excluding cable management, of up to about 635 mm,
with the depth from the front-most point of a fascia to a rear I/O
connector panel of a rear mounted Field Replaceable Unit (FRU) of
about 610 mm. Of course, other examples designed for other racking
systems could have different dimensions.
[0045] This example of a shelf 41 has a single enclosure, or
housing, 47 that houses a number of modular units or subsystems,
the majority of which are replaceable in the field and are
therefore known as Field Replaceable Units (FRUs). These modular
units include the information processing cartridges 43.
[0046] The shelf enclosure 47 can be fabricated from sheet material
(e.g., from steel sheet) to form a chassis portion 49 that includes
a base 51, two sides 53 and 55, a front 57 and a rear 59. The word
"front" as used here is merely used as a label herein to refer to
the face, or wall 57 of the enclosure that is located at the main
access side of the rack system 31 in use when the shelf is mounted
therein. Similarly, the words "rear" and "side" are merely used as
labels herein to refer to the faces, or walls 59, 53 and 55 that,
in use, are located at those respective positions when the shelf is
mounted in the rack system 31.
[0047] The openings 45 can be formed in the front face 57 for
receiving the information processing cartridges 43 and, as will be
explained later, apertures can also be formed in the rear face 59
for receiving further FRUs. The enclosure can further include a
removable top cover 61 that can be secured to the chassis portion
49 by suitable fastening (e.g., screws). The apertures in the front
and rear faces 57 and 59 allow at least some of the FRUs to be
inserted into and/or removed from the shelf enclosure 47 via the
front or the rear thereof, as appropriate, without removing the
shelf from the racking. Access to components mounted in the shelf
that are not accessible via one of the apertures in the front 47
and rear 59 faces can be achieved by removing the shelf enclosure
47 from the racking system 31 and then removing the top cover 61 of
the shelf enclosure 47.
[0048] FIG. 3 is a front view of an example of a shelf 41 for a
first example. A plastic front bezel 63 can be provided that fits
on the front face 57 (shown in FIG. 2) of the chassis 49 of the
shelf enclosure 47. The front bezel 63 can be formed as a unitary
removable part that spans the whole width and height of the front
of the shelf enclosure 47. The front bezel 63 could alternatively
include a number of separate components, or mouldings. The front
bezel can include a peripheral portion 64 that can provide areas
for corporate and product branding marks, for identification and
numbering for the information processing cartridge and for a bar
code label (all not shown). One or more apertures 65 can be formed
in the peripheral portion 64 of the bezel 63. The apertures 65 in
the bezel can be arranged to align with one or more apertures (e.g.
a slot (not shown in FIG. 3) in the front face of the chassis. In
use, air can pass through the apertures 65 to flow into the shelf
enclosure 47 to reach FRUs that are mounted in the shelf enclosure
47 through the rear face 59 thereof. Air flowing through the
aperture 65 flows into a plenum chamber 66 (not shown in FIG. 3) to
flow past the processing cartridges 43 to reach rear mounted FRUs.
A central area 67 of the front bezel 63 can be open allowing access
to the openings 45 in the front face 57 of the shelf enclosure 47
for insertion and removal of the information processing cartridges
43. Where no active module is mounted in a location for an
information processing module, a blanking panel, or filler panel,
such as the blanking panel 44, can be located in that location. LED
indicators 69 can be mounted on a system indicator printed circuit
board (not shown) behind a designated area of the bezel to provide
an indication of system status via light guides incorporated into
the bezel. A further system indicator board (also not shown)
carrying LED indicators can be provided inside the shelf enclosure
to be visible from the rear thereof.
[0049] As mentioned above, in the present example of a shelf, up to
sixteen information processing cartridges 43 can be installed in
respective openings 45 in the front face 57 thereof. The number of
information processing cartridges 43 actually installed in any
installation is dependent upon the system configuration required.
Various features relating to the information processing cartridges
43 that are shown in FIG. 3 will be described later.
[0050] FIG. 4 illustrates the rear of the shelf unit of FIGS. 2 and
3. This shows two different types of FRU 71 and 81 (4 units in
total) that have been inserted into respective apertures 72 and 82
in the rear of the shelf enclosure 47. The FRUs shown in FIG. 4
include two Combined Switch and Service Processors (CSSPs) 71 and
two Power Supply Units (PSUs) 81. Various features shown in FIG. 4
will be described later.
[0051] Before proceeding with a more detailed description of each
of the FRUs 43, 71 and 81 introduced so far and of the construction
of the shelf 41, there follows a brief description of an
information processing cartridge 43, a CSSP 71 and a PSU 81 with
reference to FIGS. 3, 4, 5, 6 and 7.
[0052] FIG. 5A provides a perspective view, partly from the rear,
of an information processing cartridge 43. FIG. 5B provides a
perspective view, partly from the front of the same information
processing cartridge 43. FIG. 5C provides an exploded perspective
view of the construction of the information processing cartridge
43. Here is it to be noted that the term "rear" is applied in the
context of the position, when installed, of the information
processing cartridge, with respect to the shelf 41 (i.e. in this
case the "rear" of the information processing cartridge 43 is the
innermost part of the information processing cartridge when it is
inserted in the shelf 41). Likewise, "front" refers in the present
context to the outermost part of the information processing
cartridge when it is inserted in the shelf 41.
[0053] With reference to FIGS. 3, 5A and 5B, it will be noted that
information processing cartridges are three-dimensional, having a
height (h), width (w) and depth (d). If, as in the present example,
the information processing cartridges are to be arranged in a
one-dimensional array (a row) across the shelf, then efficient
packing for the information processing cartridges is achieved where
one dimension (here the width, w) is smaller than the other
dimensions (here the depth, d, and the height, h). In a particular
example, the enclosure of a processing cartridge 43 has a height h,
width w and depth d of 115 mm, 26 mm and 315 mm, respectively,
although of course, other examples may have different
dimensions.
[0054] It will be noted that an enclosure 101 of the present
example of an information processing cartridge 43 has six,
generally rectangular, faces. For convenience only, the face that
is visible from the front of the racking when an information
processing cartridge 43 is mounted in the shelf 41 is known as the
front face 102. The opposite face is known as the rear face 103. In
the present example these two faces, as well as top and bottom
faces 104 and 105, and the side faces 106 and 107 have the shape of
elongate rectangles.
[0055] Although in the present example the information processing
cartridges have six generally rectangular faces, it will be
appreciated that other examples could have other configurations.
For example, rather than having a generally rectangular shape, the
side faces of another example of an information processing
cartridge could have the general shape of a triangle (whereby the
information processing cartridge may then only have five faces), a
pentagon (whereby the information processing cartridge may then
have seven faces), and so on. Indeed, one or more or all of the
edges could be curved. However, it will be appreciated that the
present configuration provides advantages for example, in terms of
manufacturing, engineering and packing density within a shelf
41.
[0056] In this example, the information processing cartridge
enclosure 101 is fabricated from two housing portions. The first
housing portion 109 can be fabricated from, for example, a metal
(e.g., pressed steel) and can include one side face 106, the rear
face 103 and part of the top face 104. The part of the top face
formed by the metal portion 109 is given the reference 1041 in FIG.
5A. The second housing portion 110 can be fabricated from, for
example, a plastics material and can include the other side face
107 and the front faces 102 and bottom face 105 and the remaining
part 1042 of the top face 104. In the present example, a plastics
material used is PolyCarbonate Acrylonitrile Butadiene Styrene
(PCABS), however many other plastics materials such as other ABSs
and nylons may be used. The metal portion 109 also includes a part
1021 corresponding to the front face 102 and a part 1051
corresponding to a part of the bottom face 105. The parts are
covered by the plastics portion 110 when enclosure 101 is fully
assembled. These parts are visible in the exploded view of FIG. 5C.
The two housing portions 109 and 110 are secured to one another by
fixings such as screws 118.
[0057] As shown in FIG. 5A, a groove 108 runs along the length of
the plastic top face portion 1042. This groove 108 is provided for
interfacing with a guide member of the shelf chassis (not shown in
FIG. 5A, but see FIGS. 8B and 8C). A similar groove 113 is formed
in the bottom face 105 of the plastics portion 110 as shown in
FIGS. 5B and 5C. This groove 113 is provided for interfacing with a
guide member of the shelf chassis (not shown in FIGS. 5B and 5C,
but see FIG. 8D).
[0058] The provision of the enclosure 101 means that the
information processing cartridge 43 can safely be handled by an
operator who is not a skilled technician. Also, through the use of
the enclosure 101, the information processing cartridge is a robust
unit that protects its inner workings from the outside environment
and vice versa. The use of a conductive enclosure, e.g., a metal
enclosure, can result in the information processing cartridge
including its own electromagnetic shielding. To this end, the
enclosure 101 can also be provided with an internal electromagnetic
interference (EMI) shielding member 116 as shown in FIG. 5C. The
EMI shielding member can be located between the internal components
112 of the information processing cartridge 43 (not described in
detail with reference to FIGS. 5A to 5C, but see FIGS. 11 and 18
below) and the plastics portion 110. The EMI shielding member can
be secured to the plastics portion 110, for example by heat bonding
or an adhesive. In other examples, the plastics portion could have
a conductive layer deposited thereon, or conductive plastics
material could be used. In this example, the EMI shielding member
116 is provided with electromagnetic interference (EMI) fingers 114
to ensure good contact with the shelf chassis and the adjacent
components. These fingers 114 extend through EMI finger apertures
1141 in the plastics portion 110.
[0059] As shown in FIGS. 3, 5B and 5C, the information processing
cartridge 43 incorporates an injector/ejector handle 111 on the
front face 102 for facilitating insertion and latching of the
information processing cartridge 43 within an aperture in the shelf
41.
[0060] As shown in those Figures, the handle 111 of the
injector/ejector lever extends substantially the whole height of
the front face of the information processing cartridge 43, thereby
increasing the mechanical advantage and facilitating injection and
ejection of the information processing cartridge 43. As is further
shown in those Figures, the front face 102 of the information
processing cartridge 43 has perforations 115, in the present
example slits, to allow for airflow into the information processing
cartridge 43. The front face part 1021 of the metal portion 109 has
perforations corresponding to those in the front face 102 such that
airflow into the information processing cartridge 43 is not
impeded. It will be noted in FIGS. 3, 5B and 5C that the handle 111
is narrower in its middle than at its ends. This reduces any
masking effect of the handle 111 on the airflow to the perforations
115 in the front face of the information processing cartridge 43
and facilitates grasping of handle 111. The handle 111 can be bowed
out from the front face of the information processing cartridge to
further facilitate grasping thereof and to reduce any masking
effect with regard to the perforations. In other examples, the
handle 111 could have an open frame-like structure to further
facilitate airflow.
[0061] As shown in FIG. 5A, the rear face 103 of the information
processing cartridge 43 also has perforations 117 to allow for air
to be exhausted from the rear of the information processing
cartridge 43. A fan can be located within the enclosure 101 of an
information processing cartridge 43. In the present example the fan
is a combined radial fan (blower) and heat sink to direct cooling
air onto a processor of the information processing cartridge, which
fan also encourages air movement within the enclosure 101. LED
indicators 119 (see FIG. 3 and 5B) can be provided on the front
face 102 of an information processing cartridge to indicate whether
power is on, whether service intervention is required and whether
the information processing cartridge 43 can be removed. A connector
120, for example a 40 way single connector attachment (SCA-2)
connector (a small computer systems interface (SCSI) connector),
can be provided at the rear of the information processing cartridge
43 for electrical connection of the information processing
cartridge 43 within the shelf 41. The connector 120 is
advantageously able to withstand repeated removals and insertions
of the enclosure 101 from and into a shelf 41. The connector
arrangement can include a guide pin arrangement to prevent module
misalignment during insertion of the information processing
cartridge into the receiving location.
[0062] Thus an example of features and the construction of an
information processing cartridge enclosure has been described.
Although particular materials and constructions have been
described, it will be appreciated that other examples could be
employed. Indeed, it will be appreciated that this particular
example relates to only a possible form for the processing
cartridge 43. An example of an alternative construction will now be
described with reference to FIG. 5D.
[0063] FIG. 5D provides a perspective view, partly from the rear,
of an alternative information processing cartridge 43. Here is it
to be noted that the term "rear" is applied in the context of the
position, when installed, of the information processing cartridge,
with respect to the shelf 41 (i.e. in this case the "rear" of the
information processing cartridge 43 is the innermost part of the
information processing cartridge when it is inserted in the shelf
41).
[0064] In this example, the information processing cartridge
enclosure 101 is fabricated from pressed steel to form two chassis
portions. The first portion 234 includes one side face 107, and
part of each of the front and rear faces 102 and 103 and the top
and bottom faces 104 and 105. The second portion 235 includes the
other side face 108 and the remaining part of each of the front and
rear faces 102 and 103 and the top and bottom faces 104 and 105.
The two chassis portions 234 and 235 meet at a groove 236 and are
secured to one another by fixings (e.g., one or more screws, not
shown). Grooves 236 run along the top and bottom faces 104 and 105
of the enclosure 101 and are provided for interfacing with guide
rails of the shelf chassis 49 (not shown in FIG. 5, but see FIG.
8C). A cover portion that is secured to the chassis portion forms
the other side face 106. It will be appreciated however, that in
another example, the chassis portions could be joined at a position
other than the groove 108, with the groove 108 being formed
entirely in one of the chassis portions. Alternatively, the
enclosure 101 may be constructed from a number of sheets of steel,
with each sheet forming one of the faces.
[0065] FIG. 6 provides a perspective view, partly from the front,
of a Combined Switch and Service Processor (CSSP) cartridge (or
CSSP) 71. Here is it to be noted that the term "front" is applied
in the context of the position, when installed, of the CSSP
cartridge 71, with respect to the shelf 41 (i.e. in this case the
"front" of the CSSP cartridge 71 is the innermost part of the CSSP
cartridge 71 when it is inserted in the shelf 41).
[0066] With reference to FIGS. 4 and 6, it will be noted that a
CSSP cartridge 71 is three-dimensional, having a height (h), width
(w) and depth (d). In a particular example, the enclosure of a CSSP
71 has a height h, width w and depth d of 43 mm, 202 mm and 278 mm,
respectively, although of course, other examples may have different
dimensions.
[0067] An enclosure 121 of present example of a CSSP cartridge 71
has six, generally rectangular, faces. For convenience only, the
face that is visible from the rear of the racking when a CSSP
cartridge 71 is mounted in the shelf 41 is known as the rear face
122. The opposite face is known as the front face 123. In the
present example these two faces, as well as side faces 126 and 127
have the shape of elongate rectangles. The top and bottom faces 124
and 125 are also rectangular, but not elongate in the manner of the
front, rear, top and bottom faces. Although in the present example
the CSSP cartridges have six generally rectangular faces, as for
the information processing cartridges 43 it will be appreciated
that other examples could have other configurations.
[0068] In this example, the CSSP enclosure 121 is fabricated from
steel sheet to form a chassis portion that includes the bottom face
125, the front and rear faces 122 and 123 and the side faces 126
and 127. A cover portion that is secured to the chassis portion
forms the other top face 124. The cover portion is secured to the
chassis portion by suitable fixings, for example one or more screws
128. It will be appreciated however, that in another example, other
faces, or portions, of the enclosure could form the chassis and the
cover portions. The provision of the enclosure 121 means that the
CSSP cartridge 71 can safely be handled by an operator who is not a
skilled technician. Also, through the use of the enclosure 121, the
switch cartridge is a robust unit that protects its inner workings
from the outside environment and vice versa. The use of a
conductive enclosure, e.g., a metal enclosure, means that the CSSP
cartridge includes its own electromagnetic shielding. To this end
the CSSP enclosure 121 is provided with EMI fingers 129 to ensure
good contact with the shelf chassis and the adjacent
components.
[0069] As shown in FIG. 4, the CSSP cartridge 71 incorporates two
D-shaped handles 132 to facilitate insertion and removal of the
CSSP cartridge 71 with respect to an aperture 72 in the rear face
of the shelf enclosure. A latch member 131 can be pivotably mounted
on a plate that can be secured (e.g., using screws) to the rear
face of the shelf enclosure. The latch member 131 is configured to
engage one of the handles 132 and to secure the CSSP cartridge 71
in place. In other examples, the CSSP cartridge 71 could be
provided with an injector/ejector handle in a manner similar to the
information processing cartridge. As shown in FIG. 6, the front
face 123 of the CSSP cartridge 71 has perforations 133 to allow for
airflow into the CSSP cartridge 71. As shown in FIG. 4, the rear
face 122 of the CSSP cartridge 71 has perforations 135 to allow for
air to be exhausted from the rear of the CSSP cartridge 71.
[0070] At least one fan can be located, for example behind the
perforated portion 135 of the rear face, in a CSSP cartridge 71 to
channel cooling air through the CSSP cartridge 71 from the front to
the rear. In this particular example shown, two fans are provided,
one behind each set of perforations 135. LED indicators 137, as
shown in FIG. 4, can be provided on the rear face 122 of the CSSP
enclosure 121 to indicate whether power is on, whether service
intervention is required and whether the switch can be removed.
Additional link status indicators can be provided integral to
2.times.4 stacked RJ-45 connectors 139, also shown in FIG. 4. As
shown in FIG. 4, electrical connections 141 can be provided at the
front face of the CSSP (i.e. on the face that in use is inside the
shelf enclosure 47). Suitable connections for use in the present
example include a connector for power connections, a connector for
serial management data connections and a connector for information
connections. In the present example, information connections are
implemented using an Ethernet information communication protocol,
e.g. at 1 Gigabit (Gb). However other protocols could equally be
used, for example the Infiniband information communication
protocol. The connector arrangement can include a guide pin
arrangement to prevent module misalignment during insertion of the
CSSP module into the receiving location. For this purpose, guide
pin holes 142 can be provided on the front face 123 into which
guide pins may pass to aid module alignment.
[0071] In the present example, up to two CSSPs 71 can be mounted at
any one time at the rear of the shelf unit in corresponding
apertures 72 in the rear face of the shelf enclosure 47. The number
of CSSPs 71 provided in any particular implementation depends upon
system configuration and the need, or otherwise, for
redundancy.
[0072] It will be appreciated that one possible construction of the
CSSP cartridge 71 has been described and that as for the
information processing cartridge 43, other examples could employ
other materials and/or constructions.
[0073] FIG. 7 provides a perspective view, partly from the front,
of a power supply unit (PSU) cartridge 81. Here is it to be noted
that the term "front" is applied in the context of the position,
when installed, of the PSU cartridge 81, with respect to the shelf
41 (i.e. in this case the "front" of the PSU cartridge 81 is the
innermost part of the PSU cartridge 81 when it is inserted in the
shelf 41).
[0074] With reference to FIGS. 4 and 7, it will be noted that PSU
cartridge 81 is three-dimensional, having a height (h), width (w)
and depth (d). In this particular example, the order to provide for
a dense packing of the FRUs in the rear of the shelf 41, the PSLU
cartridge 81 has two dimensions (hereinafter described as the
width, w, and the depth, d) that are generally similar. In a
particular example, the enclosure of a PSU cartridge 81 has a
height b, width w and depth d of 83 mm; 202 mm and 276 mm
respectively, although of course, other examples may have different
dimensions.
[0075] An enclosure 145 of present example of a PSU cartridge 81 is
of generally oblong shape, but has the "top" "front" edge cut away
to form an additional "top" "front" sloping face. The enclosure 145
therefore has five, generally rectangular, faces and two faces of
generally rectangular shape with one comer cut away. For
convenience only, the face that is visible from the rear of the
racking when the PSU cartridge 81 is mounted in the shelf 41 is
known as the rear face 146. The opposite face is known as the front
face 147. In the present example these two faces and the two side
faces 150, 151 are of elongate, generally rectangular shape with
one corner cut away, given that the width and depth of the PSU
cartridge are similar, whereas the top and bottom faces 148, 149,
although still rectangular, are not, in this example, notably
elongate. A top front face 148a is present at the top front of the
enclosure. Thus the front of the enclosure is sloped at the top
edge. As for the information processing cartridges 43, however, it
will be appreciated that other examples could have other
configurations.
[0076] In this example, the PSU cartridge enclosure 145 is
fabricated from steel sheet to form a housing portion that includes
the bottom face 149, the side faces 150 and 151 and the front and
rear faces 146 and 147. Cover portions that are secured to the
housing portion form the top face 148 and top front face 148a. The
cover portions are secured to the chassis portion by suitable
fixings, for example one or more screws 152. It will be appreciated
however, that in another example, other faces, or portions, of the
enclosure could form the chassis and the cover portions. The
provision of the enclosure 145 means that the PSU cartridge 81 can
safely be handled by an operator who is not a skilled technician.
Also, through the use of the enclosure 145, the PSU cartridge 81 is
a robust unit that protects its inner workings from the outside
environment and vice versa. The use of a conductive enclosure,
e.g., a metal enclosure, means that the PSU cartridge includes its
own electromagnetic shielding. To this end the PSU enclosure 145 is
provided with EMI fingers 153 to ensure good contact with the shelf
chassis and the adjacent components.
[0077] As shown in FIG. 4, the PSU cartridge 81 incorporates two
D-shaped handles 156 to facilitate insertion and removal of the PSU
cartridge 81 with respect to an aperture 82 in the rear face of the
shelf enclosure. A latch member 155 can be pivotably mounted on a
plate that can be secured (e.g., using screws) to the rear face of
the shelf enclosure. The latch member 155 is configured to engage
one of the handles 156 and to secure the PSU 81 in place. In other
examples, the PSU 81 could be provided with an injector/ejector
handle in a manner similar to the information processing cartridge.
As shown in FIG. 7, the front face 147 of the PSU cartridge 81 has
perforations 157 to allow for airflow into the PSU cartridge 81. As
shown in FIG. 4, the rear face 146 of the PSU cartridge 81 also has
perforations 159 to allow for air to be exhausted from the rear of
the PSU cartridge 81.
[0078] A pair of fans can be located behind the perforated portions
159 of the rear face of a PSU cartridge 81 to channel cooling air
through the PSU cartridge from the front to the rear. LED
indicators 161 can be provided on the rear face 146 of the PSU
enclosure 81 to indicate whether input power is good, whether
output power is good, whether service intervention is required and
whether the PSU can be removed. Electrical connectors 163 can be
provided at the front face of the PSU (i.e. on the face that in use
is inside the shelf enclosure 47) for connection to the shelf. The
PSU 81 of the present example may suitably employ an SSI-MPS
(Server Systems Interface-Midrange Power Supply) compliant right
angle connector at the front face 147 of the PSU 81 to connect to
the shelf 41. The power inlet 83 for each PSU 81 can incorporate a
cable/connector retention mechanism (not shown) on the rear face
146 of the PSU to prevent accidental or malicious removal of the
power input cord from the PSU 81.
[0079] In the present example, the shelf unit enclosure provides
slots at the rear of the shelf unit for two hot-swappable, AC input
PSUs 81. To provide redundant power supply, both PSU slots are
populated. More generally, N+M power supplies can be provided,
where N is the minimum number of power supply units needed to
support the components mounted in the shelf, and M is a selectable
number of 0, 1 or more power supplies to provide for redundancy. In
the present example, N=M=1.
[0080] It will be appreciated that one possible construction of the
CSSP cartridge 71 has been described and that as for the
information processing cartridge 43, other examples could employ
other materials and/or constructions.
[0081] If the full complement of information processing cartridges
or switches are not fitted to the enclosure, then blanking
panels/modules (e.g., the blanking panels 44 shown in FIG. 3) are
fitted to all unpopulated positions to maintain the correct airflow
and thermal characteristics of the shelf, a safe internal operating
temperature for the shelf life expectancy of all shelf components,
electromagnetic compliance (EMC) containment and electrostatic
discharge (ESD) containment.
[0082] It will be noted that each of the FRUs, such as the
information processing cartridges 43, is advantageously contained
in its own robust enclosure to facilitate EMC containment, ESD
containment, handling, storage and transportation. Each FRU can be
configured as a `sealed` unit in the sense that it can be
configured not to have field or customer serviceable parts
internally. The FRUs can be configured readily to plug into the
shelf enclosure and to be hot swappable. The FRUs can be keyed to
prevent incorrect positioning and insertion into the shelf
enclosure and are arranged positively to be retained in the shelf
by a latching/locking mechanism.
[0083] The examples of FRUs described above are not provided with
removable media. In the present example, internal data storage is
provided by 2.5" IDE 9.5 mm or 12.7 mm profile hard disk drive
(HDD) devices mounted internally in each information processing
cartridge 43 and in the CSSP cartridge 71. The drives are not
considered as FRUs and are not hot-swappable disk drives in the
present example, although they could be in other examples. In other
examples, the information processing cartridges can be configured
without internal hard disk drives.
[0084] The internal configuration of the shelf 41 and a midplane
171 contained therein is described in the following with reference
to FIGS. 8A, 8B 8C and 8D, and FIGS. 9A, 9B and 9C.
[0085] FIG. 8A is a schematic plan view showing the internal
configuration of an example of a shelf 41 with the cover 61
removed. FIG. 8B is a schematic perspective view from above the
rear of the chassis portion 47 of the shelf enclosure with the
field replaceable units removed. FIG. 8C is a schematic perspective
view from below the front of the chassis portion 47 of the shelf
enclosure with the field replaceable units and the base 51 removed.
FIG. 8D is a schematic perspective view from the front and above a
part of the base 51 of the shelf 41. FIGS. 9A, 9B and 9C are,
respectively, front, top and rear views of the midplane 171. In
this example, the midplane is, in use, mounted vertically within
the shelf 41 extending across the width W of the shelf 41 at a
position approximately half way between the front and the rear of
the shelf 41.
[0086] The vertically mounted midplane 171 extends, in this
example, across the shelf 41 and allows for the electrical
interconnection of the FRUs. The various apertures in the front and
rear faces 57 and 59 of the shelf 41, in combination with the
midplane 171, can be provided with guides (e.g., rails 181) and
keying e.g., offset connector positioning for the insertion of the
FRUs into the enclosure and midplane 171. The midplane 171 can be a
double-sided, or multi-layer printed circuit board (PCB) assembly
that can be mounted vertically in a rigid manner within the
enclosure. It can carry connectors 175 on a front surface 172 for
making electrical connection with corresponding connectors 120 on
the information processing cartridges 43. It can also carry
connectors 177 and 179 on rear surface 173 for making electrical
connection with corresponding connectors 141 and 163 on the CSSPs
71 and the PSUs 81, respectively. Conductive tracks (not shown) on
and through the midplane 171 can be provided to interconnect the
various connectors. In addition, the midplane can provide
connectors for receiving corresponding connectors connected to
first and second indicator boards 183 and 184 that each carry a
respective set of LED indicators 69. In the present example, the
midplane 171 is not configured as a FRU and is not hot swappable.
It is perforated to facilitate airflow through the shelf 41. The
midplane 171 can include openings 185, which cooperate with
openings in the enclosures of the FRUs 43 and 81, to provide a path
for cooling air to pass from the front to the rear of the shelf 41,
the cooling air being driven by fans in one or more of the FRUs,
for example in the PSUs 81, possibly also in the information
processing cartridges 43.
[0087] A plenum chamber floor member 94 can extend horizontally
from the front of the midplane 171 to the front face 57 of the
shelf enclosure, or chassis 47. The member 94 provides a floor for
a plenum chamber 66, which is supplied with air via the apertures
65 in the front bezel and, in the illustrated example, the slot
shaped aperture 68 in the front face 57 of the shelf enclosure 47.
Although, for reasons of ease of illustration a slot shaped
aperture 68 is shown, a plurality of apertures 68 aligned with the
blade receiving locations may be provided. The aperture or
apertures 68 can serve both as air vents for a flow of air to the
plenum chamber 66, and also as latching locations for latching
portions at the top of the injector/ejector levers 111 for the
blades shown in FIGS. 5B and 5C. The top and sides of the plenum
chamber are provided by the top cover 61 and side faces 53 and 54
of the shelf enclosure 47.
[0088] A plurality of cartridge guides 97 can be provided at the
underside of the plenum chamber floor member 94. In the present
example, these guides comprise sprung wire members, e.g., of a
resilient metal such as spring steel, that are attached to the top
surface of the plenum chamber floor member 94 and extend through a
plurality of apertures therethrough to result in a row of guides 97
at the underside of the plenum chamber floor member 94. This
arrangement is shown in FIGS. 8B and 8C. In FIG. 8B, the sprung
wire members 98 are shown attached to the top surface of the plenum
chamber floor member 94. In the present example, the sprung wire
members 98 are arranged in pairs, such that two guides 97 are
provided by each spring clip 98. In FIG. 8C, the guides 97 formed
by the protruding portions of the sprung wire members 98 are shown
at the underside of the plenum chamber floor member 94. Each guide
97 is advantageously positioned so as to interface with the groove
108 in the plastics material in the upper face 104 of a processing
cartridge 43 as shown in FIGS. 5A-5C to aid correct alignment and
to facilitate insertion of the processing cartridge during
insertion of the cartridge into the shelf 41. The use of the spring
clip as a guide 97 also serves to urge the processing cartridge
downwards to provide a secure mounting of the processing cartridge
43, to take account of manufacturing and operational tolerances and
to assist in insertion of the processing cartridge where an
operator does not align this absolutely correctly.
[0089] A further row of cartridge guides 99 can be provided at the
upper surface of the base 51 of the shelf 41. In the present
example, as shown in FIG. 8D, these guides 99 have a rail like
form, which can be achieved by punching or stamping through the
base 51 of the shelf 41. In this example each guide, or rail, 99
includes a pair of upstands separated by an aperture 100 through
the base 51. The size of the aperture 100 can correspond to the
width between the upstands. The separation of the upstands is
selected so that the overall width of the resulting rails is
slightly less than the width of a groove formed in the lower face
of an information processing cartridge 43. Thus, each guide 97 is
advantageously arranged so as to interface with the groove 1113 in
the plastics material in the lower face 104 of a processing
cartridge 43 as shown in FIGS. 5A-5C to aid correct alignment and
to facilitate insertion of the processing cartridge during
insertion of the cartridge into the shelf 41.
[0090] In the present example, where the guides 97 and 99 are
formed from metal, the provision of the grooves 108 and 113 in
plastics material at the upper and lower faces, respectively, of
each information processing cartridge 43 (see FIGS. 5A-5B) results
in a combination of metal and plastics materials that can provide a
low friction interaction, facilitating insertion of the information
processing cartridges.
[0091] If, for example, the information processing cartridge
enclosure is made of a metal, it may be undesirable to provide
metal guides to avoid a metal to metal interaction. In such a case,
for example, it may be desirable to form the guides from a plastics
material having a low coefficient of friction, such as
polytetrafluoroethylene (PTFE) or polythene. Plastics rails could
be attached to the underside of the plenum chamber floor member 94
and/or on the upper surface of the base 51 of the shelf 41. In such
an example, grooves on the upper and lower faces of the information
processing cartridges 43 could then be formed of metal or plastics
and still result in a low friction arrangement.
[0092] A CSSP/PSU divider 96 can be provided to the rear of the
midplane 171 and can extend horizontally to the rear face 59 of the
shelf enclosure 47. The CSSPs 71, when inserted, are supported by
the divider 96. To aid the correct insertion of the CSSPs 71, CSSP
guide pins 178 are provided on the midplane 171 at positions
adjacent connectors 177 on the midplane 171 for connection to the
CSSPs 71.
[0093] Respective positions 88 and 89 can be formed in the front
face 57 and the rear face 59 at which first and second indicator
boards 183 and 184 supporting the indicator LEDs 69 can be located.
These positions 88, 89 therefore include an aperture through the
respective face of the shelf enclosure 47 such that indicator LEDs
69 mounted onto a circuit board attached to the inside of the shelf
enclosure 47 may be viewed from outside the shelf enclosure.
[0094] There now follows are more detailed description of the
midplane 171.
[0095] As mentioned above, the midplane 171 connects all the
elements of a shelf together, including, in the present example, up
to sixteen information processing cartridges 43, up to two CSSPs
71, two PSUs 81 and the two indicator boards 183 and 184. In the
present example, due to its location within the shelf enclosure,
the midplane 171 is not configured to be swappable. Accordingly, to
maximize the system reliability, the midplane is configured to
provide as a high level of reliability as possible. To this end,
the midplane is advantageously configured without active devices
and to include the minimum number of decoupling capacitors
consistent with good design practice (ideally zero).
[0096] The midplane supports a number of paths for various power
and signal lines to interconnect the FRUs.
[0097] In the present example, each information processing
cartridge 43 has a high speed information signal connection (e.g.,
a Gigabit (Gb) Ethernet SERializer/DESerializer (SERDES)
connection) to each of the CSSPs 71, each connection consisting of
two pairs of differential signals. In a conventional manner
therefore, the tracking of the paths for these signals is arranged
to keep the pairs well balanced and on a single signal layer (i.e.
without vias) to support such differential signals at high
frequency.
[0098] In addition, in the present example, each information
processing cartridge 43 has a serial console connection to the CSSP
cartridge 71. Each connection consists of two TTL
(Transistor-Transistor Logic) level signals that make a transmit
and return (TX and RX) pair.
[0099] Also, each PSU 81 has a management signal connection (e.g.,
a serial I2C (Inter-IC Bus) connection) to the CSSP cartridge 71 to
control power and monitor environmental parameters. The I2C bus
comprises of two signals SCL and SDL (serial clock line and serial
data line). In addition, an I2C address programming pin is provided
for the PSUs 81.
[0100] Each information processing cartridge 43 and PSU 81 can
signal to the CSSP cartridge 71 that it is inserted by pulling to
ground (GND) a respective Inserted.sub.13 L signal (i.e., an active
low signal). These signals are fed to the CSSP cartridge 71 via the
midplane 171.
[0101] Each PSU 81 has five 12 Volt output rails. The routing from
each PSU 81 is arranged so that a fault in any single FRU cannot
completely interrupt the power to any other.
[0102] As mentioned above, the midplane 171 is provided with
appropriate connector arrangements for receiving the connectors on
the FRUs.
[0103] In the present example, the information processing cartridge
43 connects to the midplane 171 through a 40 pin Single Connector
Attachment (SCA-2) connector as defined by the Small Computer
Systems Interface (SCSI) standard. Accordingly, the midplane
carries corresponding connectors 175.
[0104] In the present example, each CSSP cartridge 71 connects to
the midplane 171 through a two right-angle 20 pair connector (e.g.,
2 mm HM-Zd connectors available from Tyco Electronics). The
corresponding connectors 177 on the midplane are straight male
parts with a power connector. A guide pin arrangement is provided
in addition to the connectors to prevent misaligned modules causing
bent pins during insertion. The guide pin also provides a leading
ground. The CSSP cartridge 71 also connects to the midplane 171
through a right-angled 125 way 5 row 2 mm connector. The connector
177 on the midplane 171 includes a straight male part. A guide pin
arrangement is provided in addition to the connectors to prevent
misaligned modules causing bent pins during insertion.
[0105] In the present example, as mentioned above, each PSU 81
connects to the midplane 171 through an SSI-MPS specification
connector. The contacts are configured 5P/24S/6P with sequenced
signal (S) and power (P) pins. Where the connector on the PSU is a
1450230-1 R/A male header, solder tails connector, the mating
connector 179 on the midplane can be a 1450540-2 vertical
receptacle, press-fit connector.
[0106] In the present implementation, indicator boards 183 and 184
(see FIG. 8A) are provided at the front and rear of the system and
are configured as FRUs. In this example they hold three
system-level indicator LEDs 69 and include a FRU identity (FRU-ID)
programmable read-only memory (PROM) each. Three LEDs 69 are
present on the indicator board. There can, for example, be a white
locator LED that can be switched by the user for locating the
system; a green power-on LED to indicate when the system is
powered; and an amber service-required LED to indicate a fault or
other condition requiring servicing. These LEDs can be driven by
the CSSP 71.
[0107] In the present example, identification information (FRU ID)
for the midplane 171 is held on an I2C electrically erasable
programmable read only memory (EEPROM) in the front indicator board
183. In addition to the I2C signals necessary to access the FRU ID
EEPROM, the CSSPs 71 provide a current limited supply to the
indicator boards 183 and 184 via the midplane. The indicator boards
183 and 184 are also provided with an I2C address programming pin.
Depending on the implementation, FRU ID information can be stored
instead, or in addition, on the rear indicator board 184.
[0108] As the FRU-ID for the midplane 171 is held on one or both of
the indicator boards 183 and 184, the midplane can be a totally
passive unit. The FRU-ID PROMs communicate with the CSSPs 71 via an
I2C bus. Each device on the bus has a separate I2C address. The
lower three I2C address bits of the EEPROMs used are available as
pins on the device, to allow programming with resistors. The least
significant bit of this address (A0) is passed to the midplane via
the corresponding connector. This allows the midplane 171 to
program the address of the FRU-ID differently for the front and
rear indicator boards 183 and 184, by pulling the address low for
the front board and high for the rear indicator board 183. This
ensures that both EEPROMS are available on the bus, at different
addresses. The FRU-ID for the midplane can be stored on either
front or rear EEPROM, but the present example the FRU-ID is stored
in the EEPROM on the front indicator board 183. The EEPROM can be 8
kByte or larger.
[0109] As mentioned above, the midplane 171 includes openings 185
to provide a ventilation path for cooling air passing through the
shelf 41. The cooling air passing through the shelf 41 via the
midplane 171 can be driven by means of fans provided in each of the
information processing cartridges 43 and the power supply modules
81. The openings 185 shown in FIGS. 8B, 9A, 9B and 9C form
schematic representations of openings in the midplane 171. In
practice, the openings could have any form (i.e., a series of large
openings, or a number of small perforations), arranged on the
midplane to align with corresponding openings or ventilation
apertures in the various field replaceable units 43, 71 and 81. In
this way, the path of the airflow from the front of the shelf to
the back of the shelf can be configured to be as efficient as
possible, depending on the detail configuration of the fan units
and the ventilation openings or apertures in the information
processing, switch, service processor and power supply unit modules
43, 71 and 81. Providing the fan units in the field replaceable
units 43, 71 and 81, contributes to the aim of maintaining the
chassis 49 and the midplane 171 of the shelf 41 free of active
components, thereby minimising cost, and facilitating maintenance.
Also, by providing the fan units in each of the field replaceable
units, merely inserting and removing field replaceable units
automatically adapts the flow of cooling air to the number and type
of field replaceable units inserted in the shelf 41.
[0110] As described above, in the present example each of the FRUs
is designed to be a non-user serviceable unit. Thus each FRU
presents the user with a "sealed" unit which may be inserted into
and removed from the shelf 41 as desired or required. If a FRU
ceases to be operable, then the user has a choice only of returning
the FRU to a supplier or service company for repair or of
discarding the non-operable unit. As the FRUs are non-user
serviceable, there is no requirement for a skilled technician to be
employed in inserting or removing the FRUs into or from a shelf 41.
Thus each FRU is designed such that a non-skilled person should
have difficulty in causing damage to the FRU during handling.
Moreover, the configuration and construction of the FRUs (e.g., the
injector/ejector levers, the grooves in the enclosures of the
information processing units, etc), of the shelf enclosure and the
midplane (e.g., the guide rails to guide insertion of the FRUs, the
locating pins, etc) contribute to facilitating easy insertion and
removal of the FRUs.
[0111] Shown in FIG. 10 is an example of the flow of cooling air
through the shelf 41 and FRUs 43, 71, 81 mounted therein.
[0112] In this example, the cooling air passing through the shelf
41 is drawn generally in a front to rear direction through the
shelf 41 by cooling fans mounted within the CSSPs 71 and the PSUs
81. Two separate flow paths for cooling air are provided in this
example. The first, indicated as flow path .alpha..alpha. by dotted
lines 77 provides cooling air to the CSSPs 71. The second path,
indicated as flow path .gamma..gamma. by dotted lines 78 provides
cooling air to the information processing cartridges 43 and PSUs
81.
[0113] The flow of cooling air along path .alpha..alpha. enters the
shelf 41 through the aperture(s) 65 in the front face 57 of the
shelf enclosure 47 into the plenum chamber 66. Further apertures
(not shown) could also be provided in the side faces 53 and 55 of
the shelf enclosure 47 to allow air to flow into the plenum chamber
66. This air then flows through the plenum chamber 66, and passes
over the top edge of the midplane 171 to reach the perforations 133
of the front face of the CSSPs 71. The cooling air then passes
through the CSSPs 71, providing cooling to the components thereof
before passing out of the CSSPs 71 through the perforations 135 in
the rear face of the CSSPs 71 thus being exhausted from the shelf
41. This flow of cooling air along flow path .alpha..alpha. is
driven by fans 79 mounted within the CSSPs 71. In the present
example, a pair of fans 79 is provided within each CSSP 71 and is
mounted against the rear face thereof.
[0114] Air flowing along path .alpha..alpha. is impeded from
flowing around the processing cartridges 43 by plenum chamber floor
member 94 and is impeded from flowing to the PSUs 81 by CSSP/PSU
divider 96. This flow path .alpha..alpha. therefore ensures that
air flowing to the CSSPs 71 is not warmed by passage though the
processing cartridges 43 and therefore provides maximum efficiency
cooling to the CSSPs 71.
[0115] The flow of cooling air along path .gamma..gamma. enters the
shelf 41 through the perforations 115 in the front face of the
information processing cartridges 43. The air thus enters the
information processing cartridges 43 and provides cooling to the
components thereof. Cooling fans (not shown) within the information
processing cartridges 43 direct the cooling air to the processor
(CPU) of the information processing cartridge and direct the flow
of air in the cartridge thereby increasing cooling efficiency. The
air then exits the information processing cartridges 43 through the
perforations 117 in the rear face thereof. The air then passes
through the apertures 185 through the midplane 171 to reach the
PSUs 81. This cooling air then passes though the perforations 157
on the front and upper front faces of the PSUs 81 to enter the PSUs
and provide cooling to components thereof. It will be appreciated
from FIG. 10 that the sloping rear of the upper face of the PSUs 81
increases the area over which air can be drawn into the PSUs,
thereby reducing the back pressure on the air flowing through the
shelf unit and aiding the cooling efficiency. The flow of cooling
air along path .gamma..gamma. is driven by fans 85 mounted within
the PSUs 81. In the present example, a pair of fans 85 is provided
within each PSU 81 and are mounted against the rear face
thereof.
[0116] Air reaching the PSUs 81 via path .gamma..gamma. will
already have passed through the processing cartridges 43. Such air
will therefore be already warmed above the ambient temperature
outside of the shelf 41 by its passage through the processing
cartridges 43. However, as the cooling requirement of the PSUs 81
is typically less than that for the CSSPs 71, this does not cause
any difficulty in the operation of the PSUs 81, which are
adequately cooled by this flow of pre-warmed air. The pre-warmed
air passing through the apertures 185 through the midplane 171 is
impeded from flowing into path .alpha..alpha. and entering the
CSSPs 71 by the SCCP/PSU divider 96.
[0117] As will be appreciated by the skilled addressee, the
arrangement shown in FIG. 10 is illustrative only and other
arrangements whereby, for example, a mixture of cool air from the
plenum chamber 66 and warmed air from the processing cartridges 43
is provided to each rear-mounted FRU can readily be
constructed.
[0118] With reference to FIG. 11, there now follows a description
of functional elements of an information processing cartridge 43 as
contained within the information processing cartridge enclosure
101.
[0119] The information processing cartridge 43 includes a
microprocessor 192 (a non-limiting example of a microprocessor that
can be utilised in the present example is an UltraSPARC.TM.
processor). The microprocessor is mounted on an information
processing cartridge motherboard 191.
[0120] A configurable clock generator 193, configured as a
programmable clock synthesizer employing a crystal, can be used to
produce CPU clock signals, CLKA and CLKB. The clock frequency can
be determined by jumper settings (not shown). A vectored interrupt
controller (I-Chip) 194 and a configurable core voltage regulator
module (VRM 195 are provided.
[0121] In the present example, memory means for use by the
processor 192 when executing instructions can be provided in the
form of buffered dynamic random access memory (DRAM), for example
configured as dual in line memory modules (DIMMs) 196 with a 72-bit
data path with error correction codes (ECC), seated in two sockets
on a riser card from the information processing cartridge
motherboard 191. The memory capacity can be chosen to suit the
processor addressable memory space. For example, in the present
example, up to 4 Gigabytes (4GB) of addressable memory can be
provided. Serial Presence Detect (SPD) auto-configuration is
provided via a Service Management Bus (SMBus) over an I2C bus
197.
[0122] In the present example, a PCI bus architecture can be
employed with a so-called SouthBridge bus bridge 199 with Super IO
and two Gb Ethernet Media Access Control (MAC) devices. As
described above, however, other bus protocols (e.g., Infiniband)
can be used. A 32 bit PCI bus 198 can be provided from the
microprocessor 192. The SouthBridge 199 is a standard form of bus
bridge, in the present example packaged in a 352 pin PBGA (Plastic
Ball Grid Array) package, that provides the following functions: an
SM Bus interface over the I2C bus 197 for access to the SPD (Serial
Presence Detect) feature of the DIMMs that allows initialization of
the memory controller; an Xbus interface for access via an Xbus 200
(which is a packet switched multiprocessor bus) to a PROM 201, a
real time clock (RTC) 202 and an information processing cartridge
service controller (hereinafter termed a Blade Service Controller
(BSC)) 203; an IDE (Integrated Drive Electronics) interface that
provides an ATA-100 (AT Attachment) IDE connection 204 to an IDE
disk drive 205; and a serial console interface on a service bus 206
to the BSC 203 that is used for operating system functions
including a console function with this embodiment.
[0123] For IO to the midplane 171, two AC-coupled Ethernet
Interfaces 207 and 208 are provided in the present example, which
are packaged in a 316 pin PBGA. These Ethernet interfaces can
provide a PCI attached Ethernet MAC capable of operation up to
Gigabit Ethernet performance. The physical layer can be implemented
using SERializer/DESerializers (SERDESs) 209 and 210. An example of
a SERDES device is the TLK2201 transceiver manufactured by Texas
Instruments, Inc. The SERDES devices use differential PECL TX+/-
and RX+/- (Positive Emitter Coupled Logic Transmit and Receive)
pairs to communicate to the switch portions of the CSSPs 71 over
the midplane 171. The RX+/- pairs can be AC coupled at the
information processing cartridge 43, the TX+/- pairs can be AC
coupled at each CSSP 71. This facilitates hot-swap of the
information processing cartridges 43 and the CSSPs 71.
[0124] Asynchronous serial connections 211 and 212 for
communication between the BSC 203 and the Service Processor parts
of the CSSPs 71 can be provided.
[0125] Internal data storage can be provided in the present example
by a hard disk 205 with a capacity of 30GB or more rated for 24/7
continuous operation. The hard disk 205 is accessed using the
primary IDE interface of the SouthBridge 199. The hard disk 205 can
hold an operating system, for example a Solaris operating system,
and other software and data for performing information processing
using the main, or host, processor (CPU) within the information
processing cartridge 43.
[0126] In the present implementation, the BSC 203 can be
implemented as a microcontroller (e.g., a Hitachi H8
microcontroller). The BSC 203 can provide various functions,
including for example: dual access (for the information processing
cartridges and the CSSPs 71) to PROM 201 and EEPROM 213 for boot
information and a FRU-ID for the information processing cartridge;
channeling communication between an information processing
cartridge 43 and the service processor part of the CSSPs 71;
control of power on reset (POR), system reset and externally
initiated reset (XIR) to the microprocessor 192; control of the
power, service-required and ready-to-remove LEDs 69; upgrading of
field-upgradable firmware, via the serial interface; a watchdog
function for the operating system; monitoring the speed of a CPU
fan 214; and communications with an EEPROM 215 and the operating
system via the Xbus 200.
[0127] In the present example, the BSC 203 can be powered by a 5V
service bus (SB) rail as soon as a CSSP 71 and a PSU 81 are fully
inserted into the midplane 171, it then turns on other DC/DC
converters to provide power to the remainder of the information
processing cartridge 43. A BSC reset signal can be derived from a
simple conventional power on reset (POR) generator that monitors a
5V supply rail.
[0128] In the present example a 1MByte Flash PROM 201 can be
provided for storing boot variables for OpenBoot.TM. PROM (OBP) and
Power-On-Self-Test (POST). Further OBP variables can be stored in a
second 16 kByte (16 kB) I2C PROM 215, accessible via the
SouthBridge SM Bus port over the IC Bus 197. The PROM 215 can
contain 8 kByte for OBP variables and 8 kByte of unused space. A 16
kByte I2C EEPROM 213 that is accessible via the BSC 203 can contain
BSC variables and FRU-ID variables. The EEPROM is nominally divided
into 8 kByte for FRU-ID and 8 kByte for the BSC variables. Write
protection for the FRU-ID is implemented by BSC firmware. Such
write protection may be carried out by, for example, acknowledging
instructions to write to the protected area, but not to carry out
those write instructions.
[0129] An environmental monitor sensor 215 can be provided to
monitor the CPU and ambient temperatures. This sensor can be
accessible via the onboard I2C bus from the BSC 203.
[0130] The information processing cartridge 43 can be powered from
two, diode commoned, 9V power supply rails 216 and 217. DC/DC
converters 218 can be used to provide the voltage levels required
by the information processing cartridge 43. The DC/IDC converters
218 are supplied by dual 9V inputs 216, 217, individually fused
219, 220 and then diode commoned 221, 222. A 5V DC,DC converter can
be turned on as soon as the FRU is fully inserted, with the BSC 203
and required portions of the SouthBridge 199 being powered (the
5VSB rail). A field effect transistor (FET) can be used to gate off
the main 5V supply to the rest of the information processing
cartridge 43. The DC/DC converter outputs and the main 5V FET can
be arranged not to turn on until the BSC 203 turns them on via a
signal from the SouthBridge 199. The SouthBridge 199 can be used so
that if the BSC 203 is reset (by a watchdog timeout or after a
firmware download) the state of the DC/DC converters 218 is not
affected. When the remaining outputs from the DC/DC converters 218
are within specification, a PWR_GOOD signal can be asserted low to
the BSC 203.
[0131] A SouthBridge resume circuit can be operable to run from
3V3, and a simple Zener diode dropper circuit can be used to
generate 3V3 from the 5VSB supply.
[0132] When the FRU is inserted the inrush current can be limited,
for example to <1A, and the rate of rise can be configured not
to exceed a predetermined value (e.g., 20A/s) to provide a
so-called soft start to facilitate hot-insertion. The intent is to
prevent damage to the connectors and to avoid generating noise. A
soft start controller 223, which controls a ramping-up of voltage
levels, can be enabled when the predetermined signal (Inserted_L
signal) is asserted low, this signal is on a short pin in the
connector and is connected to ground (GND--not shown) through the
midplane 171.
[0133] In the present example, a processor impingement fan
(processor fan) 214 is configured to run at full speed to cool the
information processing cartridge 43 and the fan. The speed of the
processor fan and sink can be monitored by the BSC 203, using a
tachometer sense pin on the microcontroller. In the event of the
fan speed falling below a predetermined speed, or percentage of its
nominal speed (e.g., 80%), the BSC 203 can be arranged to issue an
alert. The nominal speed of the fan can be recorded as part of the
BSC EEPROM contents.
[0134] The midplane connector 120 for the information processing
cartridge 43 is used to establish the connection between the
information processing cartridge 43 and the midplane. In the
present example it supports up to 84 connections (pins) that will
deliver SERDES outputs 224, 225, I2C signals 226, 227, and power
216, 217. Signal connections may be made through a right-angled
connector. Power connections may be made through the information
processing cartridge right-angled connector. The connector can be
configured to facilitate hotswapping of the information processing
cartridge, for example by having a low insertion force and/or guide
pins to increase the ease of serviceability and prevent module
misalignment during insertion.
[0135] Interrupts to the processor 192 can be encoded using an
encoded interrupt vector mechanism. An I-Chip Emulator (ICE) 228
functions as an interrupt concentrator, receiving all system
interrupts and encoding them as an interrupt vector according to an
interrupt vector code utilisable by the processor 192. In the
present example, where an UltraSPARC.TM. processor is used, the
interrupt vector encoding may be based on a 6-bit interrupt vector
code.
[0136] With reference to FIG. 12, there now follows a description
of an example of a combined switch and service processor (CSSP) 71.
In the present example, each CSSP 71 provides the functionality of
a Switch 73 and of a Shelf Service Processor, or Shelf Service
Processor (SSP) 74.
[0137] FIG. 12 provides an overview of the functional components of
the CSSP 71 including functional components of the Switch 73 and
functional components of the SSP 74. In the present example, most
of the components relating to the Switch 73 are mounted on a Switch
PCB 231, and the components relating to the SSP 75 are provided on
a SSP PCB 232. However, it should be noted that the components
located in the lower portion of the switch PCB 321 (i.e., that
portion below the SSP PCB 232 as illustrated in FIG. 12 logically
belong to the SSP 74, rather than to the switch 73. It will be
appreciated that such component arrangements are not compulsory for
successful operation and that any other component arrangement over
any number of component boards can be easily achieved using
conventional component arrangement techniques.
[0138] Firstly, with reference to FIG. 12, there follows a
description of functional elements of the Switch portions 73 of a
CSSP 71 as contained within the CSSP enclosure 121.
[0139] The midplane connector 141 on the CSSP 71 establishes the
connection between the CSSP 71 and the midplane 171. In the present
example, it supports up to 84 connections (pins) that will deliver
SERDES outputs 265-268, I2C signals 310, 320, 321 and 322, and
power 278, 279. Signal connections may be made through two 20-pair
right-angled connectors. Power connections may be made through a
right-angled connector. The connector can be configured to
facilitate hotswapping of the board, for example with a low
insertion force. The connector also uses guide pins to increase the
ease of serviceability and prevent module misalignment during
insertion.
[0140] A switch microprocessor 240 is provided, in the present
example the microprocessor used is a Power PC (MPC8245) packaged in
a 352 pin Tape Ball Grid Array (TBGA) package. This microprocessor
240 supports between 1MB and 2GB of address space in the present
example. It further includes an Embedded Programmable Interrupt
Controller (EPIC) that provides 5 hardware interrupts (IRQs) or 16
serial interrupts. There are 4 programmable timers with cascade
mode function. DRAM memory for the processor can provided in the
present example by a commodity DIMM 242. The processor 240 can be
connected to a 32 bit PCI bus 241, which operates at, for example,
33MHz/66MHz.
[0141] A clock input to the processor 240 can be provided by a
clock generator (CLK) 243. The CLK 243 can include a configurable
clock generator (not shown) implemented as a programmable clock
synthesiser employing a crystal used to produce CPU clock signals.
The clock frequency can be determined by jumper settings (not
shown). A vectored interrupt controller (I-Chip) (not shown) and a
configurable core voltage regulator module (VRM) (not shown) can be
provided that operate substantially as described above with
reference to the like components of FIG. 11.
[0142] In the present embodiment two switch ASICs (application
specific integrated circuits) 244, 245 are provided (in the present
example, BCM5632 Gigabit switch ASICs). Each ASIC can provide
twelve GMII Interfaces (1 Gigabit Ethernet) (for uplinks and
downlinks) and one 10Gb XGMII interface for chip-to-chip
communication (bridging) 246 between the ASICs 244 and 245. Sixteen
GMII 1Gb `downlinks`, in the form of serialized Gb Ethernet data,
are provided through four quad SERDES 248-251 to allow each
information processing cartridge 43 to communicate with the switch
73. Eight GMII 1Gb `uplinks` are provided for external
communication through two quad PHYs 253 and 254 (in the present
example BCM5404 ASICs) and RJ45 connectors on the rear panel 122.
The ASICs 244 and 245 are configured via a PCI interface (32
bit/33MHz) to the PCI bus 241.
[0143] A Flash PROM 256 can store a real time operating system, and
management and configuration data for the microprocessor. The Flash
PROM 256 in the present example can be operable to hold 8MB-16MB of
data, depending on the software required. The flash PROM 256 can be
operated via an on-chip XBus 258.
[0144] Also connected to communicate with the processor 240 via the
XBus 258, a Real Time Clock (RTC) 259 can be provided for real-time
functions with a back-up battery.
[0145] Also connected to the XBus 258 can be a UART (Universal
Asynchronous Receiver Transmitter) 260 which in turn connects to a
serial bus 261 for providing an asynchronous console connection
from the switch 73 to the SSP 74 which can be accessed by the
SSP.
[0146] An integrated MAC/PHY (Media Access Control/Physical) switch
271 can provides its own interface to the PCI bus 241. This MAC/PHY
switch 271 can connects to a 10/100 Ethernet hub 272. The hub 272
can be operable to provide a management interface to the SSP 74 and
a connection from an external management network to the switch 73
and SSP 74 of a given CSSP 71. The connection from the integrated
MAC/PITY device 271 to the SSP 74 can be coupled capacitively. A
loopback mode can be provided by the MAC/PHY device 271 for system
diagnostics. The hub 272 can connect to an RJ45 connector 273 on
the rear panel 122 of the CSSP enclosure 121.
[0147] An 8 kByte I2C EEPROM 262 can be used to store the FRU-ID
and is accessible by the SSP portion 74 of each CSSP 71 via a
serial bus 263 and the midplane 171. The upper 2 kByte of the
EEPROM 262 can be configured to be write protected.
[0148] An I2C Redundant Control Register (RCR) 275 can be used to
provide an alternate, redundant path for powering-down the CSSP 71
and Shelf Level Indicators 69 mounted on the front 57 and rear 59
panels of the shelf 41. The I2C RCR 275 can be accessible by both
the SSP 74 of the CSSP 71 containing the RCR and the SSP 74 of a
further CSSP 71 connected via the midplane 171 via an I2C bus 276.
In the present example, a device suitable for use as the RCR 275 is
a Phillips PCF8574 IC.
[0149] With continued reference to FIG. 12, there now follows a
description of functional elements of the Shelf Service Processor
(SSP) portion 74 of a CSSP 71 as contained within the CSSP
enclosure 121 and provided on an SSP PICB 232.
[0150] In the present example, communication between the Switch PCB
231 and the SSP PCB 232 is facilitated by an interboard connector
pair 298 and 299. It supports connections (pins) for I2C signals,
10/100 MAC/PHY output, and power. As described above, the switch
PCB 231 carries the components associated with the switch, and it
also carries the power, FRU-ID and environmental monitoring
components along with the connectors for connections to the
midplane 171 and external connectors. Thus, in the present example,
all SSP components requiring a connection to the midplane 171 or an
external connection have signal paths routed through the connector
pair 298, 299 and via the switch PCB 231 to the relevant midplane
or external connectors.
[0151] In the present example, the SSP 74 includes a microprocessor
301 (e.g., a Power PC (MPC8245) processor) mounted on the SSP
printed circuit board (PCB) 232. The processor 301 can be connected
to a PCI bus 302, the present instance a 32 bit bus that operates,
for example, at 33MHz/66MHz.
[0152] A clock input to the processor 301 can be provided by a
clock generator (CLK) 303. The CLK 303 can comprise a configurable
clock generator (not shown) implemented as a programmable clock
synthesiser employing a crystal used to produce CPU clock signals.
The clock frequency can be determined by jumper settings (not
shown). A vectored interrupt controller (I-Chip) (not shown) and a
configurable core voltage regulator module (VRM) (not shown) can be
provided that operate substantially as described above with
reference to the like components of FIG. 11.
[0153] The processor 301 can be provided with a DRAM memory 305.
The memory capacity can be chosen to suit the processor addressable
memory space. In the present example, 8MB of DRAM memory is
provided.
[0154] An integrated MAC/PHY switch 306 can provide its own
interface to the PCI bus 302. The MAC/PHY switch 271 can be
connected to 10/100 Ethernet hub 272 via the interboard connectors
298, 299. A loopback mode can be provided by the MAC/PHY switch 306
for system diagnostics.
[0155] Octal UARTs 308 and 309 can be connected between the PCI bus
302 and the interboard connector pair 298, 299. The signal path can
be continued from the interboard connector pair 298, 299 to serial
connections 310 on the midplane connector 141 on switch PCB 231.
The Octal UARTS 308, 309 can facilitate serial communications
between the SSP 74 and each of the processing cartridges 43.
[0156] Also connected to the PCI Bus 302 can be a dual UART (DUART)
312 that in turn can connect via the interboard connectors 298, 299
to serial bus 261 for providing an asynchronous console connection
from the SSP 74 to the switch 73. The DUART 312 can also have an
I2C connection to an external connector on the rear face 122 of the
CSSP enclosure 121. The external connector can provide a common
operating system/boot console and command port 311.
[0157] Connected to the processor 301 via an XBus 314 can be a
Flash PROM 315. The Flash PROM 315 can store a real time operating
system, and management and configuration data for the
microprocessor 301. The Flash PROM 315 can be operable in the
present example to hold up to 2MB of data, depending on the
software required.
[0158] Also connected to the processor 301 via the XBus 214 can be
a real time clock (RTC) 316 for real-time functions with a backup
battery. The RTC 316 can also provide 8 kByte of non-volatile
random access memory (NVRAM), in the present instance implemented
as an EEPROM. This can be used to contain information such as the
FRU-ID, a serial number and other FRU information.
[0159] To facilitate I2C communications between the SSP 74 and the
other CSSP 71, the midplane 171 and the PSUs 81, a multiplexer 318
can be provided. The multiplexer 318 can have a single I2C
connection to the processor 301 and connections, via the interboard
connector pair 298, 299 and the midplane connector 141 to both PSUs
81, the midplane 171 and the other CSSP 71.
[0160] The processor 301 can also comprise an embedded DUART to
provide a redundant serial link to the SSP 74 of the other CSSP 71.
Although it would be possible to implement this link using an
external DUART, the advantage of using an embedded DUART is that
the connection to the other CSSP is reliable and therefore likely
to be functional. Where the embedded DUART link does not use the
I2C Multiplexer for communications to the other CSSP, a common mode
of failure for both the SSP-SSP I2C links can be avoided, it being
assumed that the processor 301 is likely to be functional even if
both embedded DUART channels are non-functional.
[0161] The CSSP 71 can powered from two, diode commoned, 9V power
supply rails 278 and 279. DC/DC converters 281 can be used to
provide the voltage levels required by the CSSP 71. The DC/DC
converters 281 can be supplied by dual 9V inputs 278, 279,
individually fused 285, 286 and then diode commoned 287, 288. A
soft start controller 283 can be provided to facilitate
hot-insertion. A 5V DC/DC converter (I2C power regulator) 282 can
be turned on as soon as the CSSP 71 is fully inserted. A 3.3V DC/DC
converter can be turned on when instructed, for example through SSP
service software, by asserting low an appropriate signal (ON_L--not
shown). The 3.3V converter can be arranged to turn on a converted
for 2.5V, 1.2V, and a processor core voltage rail (Vcore) when the
voltages are within an appropriate range.
[0162] When the CSSP 71 is inserted the inrush current can be
limited, for example to <1A, and the rate of rise can be
configured not to exceed a predetermined value (e.g., 20A/s) to
provide a so-called soft start to facilitate hot-insertion. The
intent is to prevent damage to the connectors and to avoid
generating noise. A soft start controller 283, which controls a
ramping-up of voltage levels, can be enabled when the predetermined
signal (Inserted_L signal) is asserted low, this signal is on a
short pin in the connector and is connected to ground (GND--not
shown) through the midplane 171 until one of the supplies is
removed. These circuits can be configured to withstand an
overvoltage at their inputs whilst the input they are feeding is
not powered, without any leakage to the unpowered circuit. A sense
circuit can detect if the voltage has dropped below a threshold,
for example 2.0V, as a result of a blown fuse, a power rail going
down, etc. The DC/DC converters 281 can be protected against short
circuit of their outputs so that no damage occurs.
[0163] The I2C regulator 282 can be powered as soon as the CSSP 71
is fully inserted into the midplane 171. This can be facilitated
through short pins connected to the soft start controller 283,
which controls a ramping-up of voltage levels. The other DC/DC
regulators can be turned on, for example by SSP software.
[0164] A pair of fans 290, 291 can provide cooling to the CSSP 71.
The fans 290, 291 can be configured to run at full speed to prevent
overtemperature conditions by minimizing the temperature of the
internal components and the fan. The speed of the fans 290, 291 can
be monitored by the SSP 74 through an environmental monitor 295 on
the switch board 231. The environmental monitor 295 can be alerted
in the event of the fan speed falling below a predetermined value
(e.g., 80% of its nominal speed). The fan can provide tachometer
outputs to facilitate the measurement of fan speed.
[0165] LED indicators 137 can be provided, for example with a green
power LED, an amber LED for indicating that service is required and
a blue LED for indicating that the switch is ready to be removed.
LED indicators integrated on 2.times.4 stacked RJ45 connectors on
the rear face of the CSSP 71 can be arranged, for example, to show
green continually when the link is present and flash green when the
link is active.
[0166] The environmental monitor ENVT MON 295 can be provided to
maintain operational integrity of the CSSP 71. The ENV MON 295 can
include limit values in limit registers and can monitor, for
example, temperature within the CSSP enclosure 121, the CSSP power
rails, including the 12V, 3V3, Switch Processor Core Voltage, CSSP
Processor Core Voltage and the two 9V power feed rails 278, 279
from the midplane 171. The outputs of the DC/DC converters 281 can
be fed in to A/D inputs of the ENV MON 295 for Watchdog comparisons
to be made to the voltage limits set in the limit registers. As
noted above, the ENV MON 295 can also monitor the operating speeds
of the fans 290 and 291. The ENV MON 295 can communicate with the
SSP 74 of both CSSPs via an I2C bus 296.
[0167] For IO to the midplane 171 shown in FIGS. 8A-10, the
midplane connector 141 can include sixteen 1Gb Ethernet connections
265-268 from four quad SERDES 248-251 and the I2C bus lines
596.
[0168] The SSP 74 can access the I2C devices (FRU-ID EEPROM, 8-bit
I/O expansion chip, and the system hardware monitor) through the
midplane 171.
[0169] For external IO, rear panel Gb Ethernet connections can be
provided from the two quad PHYs 253, 254 to 2.times.4 stacked RJ45
connectors 139 (to give 8 uplinks). Each port can be an independent
10/100/1000 BASE-T (auto negotiating) port. The PHY devices 253,
254 can operate in GMII mode to receive signals from the 8-Gigabit
interfaces on the ASICs 244, 245.
[0170] The Power Supply Units (PSUs) 81 can configured such that
when two or more PSUs 81 are connected in parallel in the shelf 41,
failure of any one of the paralleled units shall not affect system
operation. Moreover, one of the PSUs can be installed or removed
from a "live" system with or without input power applied. The
outputs can have overcurrent protection.
[0171] The PSU can have an I2C interface to provide power supply
status via the midplane 171. The PSU can have an internal
temperature sensor that reports via the I2C interface. The PSU fan
speed can also be monitored and errors are reported via the I2C
interface. Overvoltage and overcurrent sensors can also report via
the I2C interface.
[0172] There now follows a description of aspects of an example of
a power supply 81 with particular reference to FIG. 13.
[0173] When a power supply (e.g. mains power, or UPS type protected
power) is connected to the cable connector 83, transformer,
regulator and rectifier circuitry 400 can operate to generate a DC
output (in the present example, 12V DC) from the input (in the
present example 230/240V 50Hz AC or 110V 60Hz AC).
[0174] In order to ensure good cooling reliability within the shelf
41, each PSU 81 can have a pair of cooling fans 402, 403 located at
the rear of the PSU enclosure as described above with reference to
FIG. 7. As a failsafe measure against a failure of one PSU 81, the
fans of each PSU 81 can be powered by both PSUs 81. Thus, in the
event that one PSU 81 is non-operative to produce the DC supply for
the shelf 41, as long as the other PSU 81 is operative, not only
will all components of the shelf 41 be powered as normal, the fans
of both PSUs 81 can continue to run.
[0175] As shown in FIG. 13, this dual powering of cooling fans 402,
403 can be effected by providing a power supply line 404 from the
transformer, regulator and rectifier circuitry 400 to power both
fans 402, 403. Also, first and second separate power lines 410, 412
from the other PSU 81 can provide duplicate power supply to the
first and second fans 402, 403 respectively. The fan 402 can thus
be powered by a diode commoned supply from line 404 and a diode
commoned supply from line 410. Diode protection can be provided by
diodes 405 and 411 respectively. The speed of the fan 402 can be
controlled by a speed controller 408. Similarly the fan 403 can be
powered by a diode commoned supply from line 404 and a diode
commoned supply from line 412. Diode protection can be provided by
diodes 406 and 414 respectively. The speed of the fan 403 can be
controlled by a speed controller 409.
[0176] The two speed controllers 408, 409 can in turn be controlled
by a data input from each CSSP 71 received via an I2C bus
connection (not shown in FIG. 13). Power supply lines carrying DC
power for the other FRUs of the shelf 41 are shown in FIG. 13 as
power line 416. All power connections to and from the PSU 81 can
connect to the midplane 171 when the PSU is inserted in the shelf
41 via the midplane connector 163. In the present example the PSU
81 connects to the shelf through a 5P/24S/6P configuration SSI-MPS
compliant right angle connector 163 at the front face 147 of the
PSU 81. Connectors for the I2C interface can also be provided.
[0177] The input power line 410 and 412 for each fan 402 and 403
can be provided with a softstart module 4131 and 4132 respectively,
to allow for hot insertion of the PSU 81 into the shelf 41. The
softstart modules 4131 and 4132 can be controlled, for example, by
pulling a signal to ground (e.g., a "mated" input line 4151 and
4152).
[0178] Where the two input power lines 410 and 412 are separate
lines having separate softstart provision, there is no common
failure mode for the backup method of powering the fans 402, 403.
Thus even if the PSU 81 ceases to be operable to generate the DC
supply, and a component (power line or softstart module for
example) fails in the supply path from the second PSU 81 to the
fans 402, 403, at least one of the fans 402, 403 can remain
operational as the shelf 41 still receives the cooling effect of
three PSU fans.
[0179] In the present example, the power supply has four rear panel
LED indicators 137. A blue "Ready to Remove" LED can be driven by
the I2C interface and indicate that the power supply may be removed
from the system. An amber "Service Required" LED can be driven by
the I2C interface and indicate that the power supply is in a fault
condition: any output out of range, over-temperature or shutdown. A
green "DC Output-OK" indicator can be driven by internal power
supply circuits and show that the main 12 volt supply is
functioning. The LEDs can remain lighted when individual outputs
are in the current limited mode of operation. A green "AC InputOK"
indicator can be driven by internal power supply circuits and show
that AC input power is within normal operating range.
[0180] With reference to FIG. 14, there will now be described an
example of data connectivity between the FRUs and midplane of the
shelf 41. Power transmission paths are not illustrated in FIG. 14.
However, it will be appreciated that to facilitate the maximum
component redundancy of the shelf 41, each PSU 81 can independently
provide power to each FRU.
[0181] In the present example each of the processing cartridges
(blades) 43 connects to the midplane 171 via a pair of information
signal connections (e.g. Gb Ethernet links) 224, 225 and a pair of
serial management signal connections 226, 227. Connections within
the midplane 171 can ensure that each Ethernet link 224 is directed
to a connection 265-268 from the midplane 171 to a first switch 73,
and that each Ethernet link 225 is directed to a connection 265-268
from the midplane 171 to a second switch 73. Thus one Ethernet link
can be established between each processing cartridge 43 and the
switch 73 of each CSSP 71. Further connections within the midplane
171 can ensure that each serial connection 226 is directed to a
connection 310 from the midplane 171 to the first SSP 74 and that
each serial connection 227 is directed to the second SSP 74. Thus
one serial link can be established between each processing
cartridge 43 and the SSP 74 of each CSSP 71. As mentioned earlier,
information signal connections other than Gb Ethernet connections
(e.g. Infiniband connections) could be employed in other
examples.
[0182] A plurality of serial connections can connect each SSP 74 to
the other. Serial lines 320, 321 can connect each SSP 74 to the
midplane 171 and connections within the midplane can connect the
two sets of lines together. To provide a control interface from the
SSPs 74 to the PSUs 81, serial lines 322 can connect each SSP 74 to
the midplane 171 and connections within the midplane 171 can
connect to serial lines 324 from the midplane 171 to each PSU
81.
[0183] An example of data and control connectivity of the shelf 41
to and from computer systems external to the shelf 41 when the
shelf 41 is arranged for use within a multiprocessor server system
such as that described above with reference to FIG. 1 will be
described with reference to FIG. 15.
[0184] As summarised above with reference to FIG. 14, in the
present example each processing cartridge, or blade, 43 is
connected to the switch 73 of each CSSP 71 by an information signal
connection (e.g. a 1Gb Ethernet link) formed by a combination of
links 224, 225 from the processing cartridge 43 to the midplane
171, connections within the midplane 171 and links 265-268 from the
midplane 171 to each switch 73.
[0185] Further, in this example a set of serial management signal
connections comprising links 320, 321 and connections within the
midplane 171 connect the SSP 74 of each CSSP 71 to the SSP 74 of
the other CSSP 71.
[0186] To provide external data connectivity between the shelf 41
and an external core data network 330, in association with which
all information processing performed by the processing cartridges
43 of the shelf 41 is undertaken, connections 331 can be formed
between the core data network 330 and the eight 1Gb Ethernet ports
139 provided on the rear panel 122 of the CSSP enclosure 121.
[0187] In the present example, the connections by means of which
control and configuration of the shelf 41 are performed are
entirely separate to the connections to the core data network 330.
Therefore, a first external switch 335 can connect to a management
(I2C) port 273 of the first CSSP 71 and a second external switch
336 can connect to a management (I2C) port 273 of the second CSSP
72. As described above with reference to FIG. 12, the management
port 273 can provide a management network interface to both the
switch 73 and SSP 74 of each CSSP 71. The external switches 335,
336 can each be connected to each of a pair of System Management
Server (SMSs) 338, 339. The SMS is not essential to the operation
of the shelf 41, but use thereof aids optimal operation of the
shelf 41. In a typical multiprocessor server system a plurality of
shelves 41 may be connected together via the core data network 330
under the control of a single management network utilising one set
of SMSs 338, 339. A set of SMSs 338, 339 may comprise a single SMS
(as well as a plurality thereof). However use of at least two SMSs
enables redundancy of components, therefore increasing overall
system reliability.
[0188] A serial interface control 343 operable under telnet
protocol control is also connected to the shelf 41 in the present
example. This can provide a common operating system/boot console
connection to the SSP 74 of both CSSPs 71 via the RJ45 connector
311 on the rear panel 122 of each CSSP enclosure 121.
[0189] It will be appreciated from the above that a flexible and
scalable modular computer architecture has been described. In the
described example up to 16 information processing cartridges, or
blades 43, can be configured as sealed FRUs on a single shelf 41,
the number of blades being chosen according to customer
requirements. Each blade has its own processor and random access
memory. If, for example, there is a maximum of 2Gbytes of memory
per information processing cartridge, and one processor per blade,
16 processors (16P) with 5.33 processors per unit height (1U) and a
total of 32GB of memory per shelf can be provided.
[0190] In the present example, the shelf 41 incorporates redundant
combined switch and shelf service processor modules (CSSPs) 71 and
redundant power supply units (PSUs) 81 separate from the blades 43.
As the power supplies are carried by the shelf, the information
processing cartridges can be kept compact and inexpensive. Also, as
a result, they can be powered by DC power only, via the midplane
171.
[0191] Also, as mentioned earlier, the FRUs (e.g., the information
processing cartridges, or blades, 43, the CSSPs 71 and the PSUs 81)
can all be configured as sealed units that do not contain any
internal FRUs themselves and do not contain user serviceable items.
The enclosures of the FRUs can be arranged to enclose all of the
functional components of the FRU with only electrical connectors
being externally accessible and with indicator LEDs being
externally visible as well.
[0192] These factors can all contribute to keeping the cost of the
FRUs low, as well as that of the overall system. The modular
approach with the use of sealed modular field replaceable units for
providing system functionality and with non-field replaceable units
designed with a minimum possible number of active components
enhances reliability. Moreover, easy and rapid maintenance is
facilitated in the event of a failure of a FRU by simple
replacement of that FRU, further reducing the cost of
ownership.
[0193] Thus, it will be appreciated from the above description that
the provision of a rack mountable shelf, that includes power
supplies, a shelf service processor and switches in modular units,
for carrying a number of processing cartridges, wherein the number
of processing cartridges can be chosen according to customer
requirements, provides a flexible and scalable computer
configuration. The balancing of the load between the processors of
the processing cartridges can be effected by software using
conventional principles.
[0194] A configuration as described provides an easily scalable
processor architecture, whereby the processing power provided by a
complete system based on the information processing
cartridge/information processing cartridge carrier architecture can
be scalable from moderate to very high capacity through the simple
addition of further information processing cartridges.
[0195] As illustrated in FIG. 16, an example of the external
connections from a shelf 41 can be in the form of two active
information signal connections (e.g., Ethernet connections) 350 and
351, two active power connections 353 and an active/standby pair of
management connections 354. With regard to the management
connections, each connection comprises a serial connection and a
network (e.g. Ethernet or Infiniband) connection. It is possible to
connect to either the active or the standby connection, as the
incoming signal will be internally routed to whichever management
controller (CSSP) is the current master. It will be appreciated,
therefore, that the connections to a shelf can be kept to a
minimum. It will further be appreciated from the configuration
shown in FIG. 16 that the system is scalable beyond a single shelf
unit 41.
[0196] FIG. 17 illustrates how a plurality of shelves can be
configured within one (or more) racks to provide even higher
processing power. Such a constellation of shelves to provide a
large grouping of servers is sometimes termed a "web farm" or
"server farm" 360. As shown in FIG. 17, the web farm comprises a
plurality of shelves 41 that each carry a plurality of blades 43.
Also provided are a plurality of Network Attached Storage devices
(NAS) 373 for providing storage for critical data, e.g. email data
storage, for the web farm. The NASs 373 are not required if there
is no critical data to be stored, e.g. if the web farm is operating
solely to provide web caching services.
[0197] Management control of the web farm 360 can be provided
through a pair of System Management Servers (SMSs) 362. Each SMS
362 can be connected to a management network via a link 366 and to
a management console 365. The SMSs 362 can communicate with the
individual shelves 41 via a pair of management switches 364. Each
shelf 41 and NAS 373 can be connected to each management switch 364
via a connection 367. Thus dual redundant management connections
can be provided to each shelf 41 and NAS 373.
[0198] Flow of data to and from the web farm 360 can be provided
through a pair of data switches 369. Each data switch 369 can be
connected to a consumer network via a link 370. It is to be
understood that the consumer network can be a larger data network
to which the web farm 360 is connected. This network can be an
office or corporation intranet, a local area network (LAN), a wide
area network (WAN), the Internet or any other network. Connections
between the data switches and the shelves 41 can be facilitated by
connections 371. It is to be noted that as each shelf has its own
switching capability, there is no need for each shelf 41 to be
directly connected to the data switches 369. Connections can also
be provided to connect the NAS units 373 to the shelves 41. The
topology used for interconnection of the data switches 369, shelves
41 and NASs 373 can be any topology providing at least one
connection of any length between every possible pair of units.
Complex topologies arranged to minimise the maximum connection
length between any two given units in the web farm can be used.
[0199] The web farm 360 comprising a plurality of shelves 41 with
or without a plurality of NASs 373 can suitably be used as any or
all of the entry edge server group 9, web edge server group 15 and
application servers 19 described above with reference to FIG.
1.
[0200] As an alternative to providing critical data storage within
a NAS 373, such storage can be provided within one or more NAS
cartridges fitted into one or more of the shelves 41 in place of
processing cartridges 43. Another alternative is to provide a
server shelf with local storage (such as a RAID array (Redundant
Array of Inexpensive Disks) in place of the NAS 373.
[0201] Thus there has now been described an example of a fully
configurable computing system based on a plurality of self
contained field replaceable units (FRUs) and scalable from a single
processing cartridge with power supply and switching capability to
a multiply redundant multiprocessor server system with full system
management capability extending over a number of co-operably
connected server shelves. It will of course be readily apparent to
the skilled reader that many of the specific features specified in
the above description are in no way limiting and a variety of
alternatives may be produced using only ordinary skill and common
general knowledge. Non-limiting examples of example modifications
which may be made to the above described system are discussed
hereafter.
[0202] There is no limit placed on the processing cartridges as to
what software they should run. Each module within a shelf or farm
may run under the same operating system, or a plurality of
different operating systems may be used. Examples of possible
operating systems include Sun Microsystems' Solaris.RTM. OS or
another UNIX.TM.-Type OS such as Linux.TM., MINIX.TM., or Irix.TM.,
or UNIX.TM. or a Microsoft OS such as Windows NT.TM., Windows
2000.TM., Windows ME/98/95.TM., Windows XP.TM..
[0203] It is also not necessary that each processing cartridge
within a shelf or farm be configured to run the same program
software. For example, individual processing cartridges may be
configured to execute, for example, fileserver software, mailserver
software, webhosting software, database software, firewall
software, or verification software.
[0204] Although it has been described above with reference to FIGS.
4, 8, 12, 13 and 14, that functionality of a switch and of a shelf
service processor should be provided within a single combined
switch and service processor unit, this is not essential and
separate switch and shelf service processor field replaceable units
may be used.
[0205] Although it has been described above that a pair of PSUs and
a pair of CSSPs may be provided so as to enable dual-redundancy,
further PSUs and CSSPs may be provided so as to increase FRU
redundancy further, thus providing statistically higher
reliability.
[0206] In the power supply circuitry in each of the blades and
CSSPs, two voltage sense circuits may be provided after the fuses
and before the diodes, to prevent a latent fault caused by a failed
fuse going undetected until one of the PSUs is removed or taken
offline. Such circuits may configured to withstand an overvoltage
at their inputs whilst the input they are feeding is not powered,
without any leakage to the unpowered circuit.
[0207] Although it has been described above with particular
reference to FIG. 11 that the processing module may be based on an
UltraSPARC.TM. processor, this is not limiting and any other
processor having sufficient processing capacity to undertake the
tasks required of a particular processing cartridge may be used.
Alternative processors include, but are not limited to, Intel x86
series and compatible processors, AMD x86 compatible processors,
Alpha processors and PowerPC processors. The particular example of
an x86 compatible processor is described in more detail with
reference to FIG. 18. In FIG. 18, the parts corresponding to those
of the UltraSPARC.TM. based system of FIG. 11 have the same
reference numerals and will not be described again here. In a
system based on an x86 compatible processor, the processor 378
itself communicates with the other components, including the memory
196 and PCI bus 198 via a Northbridge 379. The Northbridge 379 also
includes an interrupt controller, so no separate interrupt
concentrator is required. The other components of the processing
cartridge could be substantially the same as for the UltraSPARC.TM.
based system described above.
[0208] Although it has been described above that each information
processing cartridge comprises a single microprocessor, this is not
a limiting case as each or any of the information processing
cartridges may have more than one microprocessor arranged to share
common storage resources to operate synchronously (in lockstep) or
asynchronously. Also, it is not necessary that all information
processing cartridges inserted into a shelf at a given time are
identical, rather a variety of different blade architectures may be
used simultaneously.
[0209] The provision of the functions of both Switch and Shelf
Service Processor within a single FRU in the present example
provides a facility within a single shelf 41 for dual redundancy in
both functions in fewer different FRUs. As will be appreciated,
there is no restriction that these two functions must be provided
within a single FRU and division of the two functions into separate
FRUs would present no difficulty to the skilled addressee.
[0210] The backup power provision for the cooling fans of the PSUs
is described above with reference to FIG. 13. Although it is
described that the backup power supply to each fan should be
independent of the other, if the risk of common mode failure of
backup power supply is judged to be low, or is of low importance,
then the backup supply to each fan may be provided in common with
the backup supply to all other fans.
[0211] Also, an information processing module forming a field
replaceable server blade can include a processor and memory can be
configured by means of software, firmware or hardware to provide a
special purpose function. By way of examples only, an information
processing module can be configured to perform the function of one
or more of a firewall, or a load balancer, encryption and/or
decryption processing, an interface to a secure network, e.g. a
virtual private network (VPN), a specialized switch with wide area
network (WAN) connectability.
[0212] Also, a storage blade may be provided. The storage blade can
be configured to be mountable in a server blade receiving location
in a blade server carrier. The storage blade can comprise storage
blade connectors configured for interconnecting with carrier
connectors on the server blade carrier, whereby the storage blade
is interchangeable with a server blade. A carrier, or shelf, for a
server system can be arranged with a plurality of blade receiving
locations for receiving blades, wherein the blades can be storage
blades or information processing blades. The server system can be
self configuring on receipt of the blades according to the type of
blade received in each said location. To achieve the blade service
controller in each blade can be operable to communicate with a
shelf service processor to perform said configuring.
[0213] Although it has been described above that one or more
standard processing cartridges 43 may be inserted into a shelf 41,
there may arise situations where a standard processing cartridge 43
may not always provide an optimum performance situation. Computer
systems require management in many different ways, for example,
load distribution, access control, secure transaction management
and many other functions which may be performed with greatest
reliability and/or speed by dedicated hardware. That is not to say
that such functions may not be performed by a standard processing
cartridge 43 programmed using appropriate application software,
merely that specialist hardware (in the form of a non-standard
processing cartridge) may provide reliability, performance and/or
cost benefits.
[0214] A computer system connected to an external network such as
the Internet may be subjected to unwanted and/or malicious
visits/attacks originating from outside that computer system. To
protect against such events, an edge protection scheme may be
employed. Under such schemes, each point of access between the
computer system and the external network may be provided with
protective measures to restrict the traffic reaching the computer
system to only that traffic which the computer system wants to
receive. Such edge protection measures may commonly be known as
firewalls.
[0215] As noted above a firewall is typically positioned between a
computer system and an external network. The computer system may
itself be a networked computer system and the external network need
not be the internet, it may be another part of a company intranet
for example. The firewall is thus tasked with ensuring that traffic
arriving at the computer system is filtered to remove any unwanted
traffic, especially including the removal of any potentially
malicious traffic. A firewall may also be configured to monitor
traffic leaving the computer system, thus in the event that a
computer system's security has been partially compromised, the
effects of this on other computer systems may be mitigated by
preventing or restricting outgoing traffic. Firewalls therefore are
tasked with a relatively wide range of tasks and functions.
Examples of firewall functions will be described in more detail
hereafter. Examples of firewall products include the FireWall-1.TM.
range of products form Check Point Software Technologies Ltd, the
BorderManager products from Novell Incorporated or the firewall
products of Securepoint.
[0216] Another function which may be performed by a firewall is one
of content security monitoring and access control. Content security
monitoring and access control may be provided for a number of
different protocols. One of the most common access control
functions is to block access to and from known security risk
origins, for example by maintaining a table of disallowed IP
addresses and paths against which all traffic is filtered. A
typical firewall may be operable to control traffic flow under any
networking protocol or protocol set. The most common internet
protocols (those defined by the TCP (transfer control protocol) and
IP (internet protocol) standards) may typically be understood by
most firewalls. Examples of protocols included in the TCP/IP suite
are http (hypertext transfer protocol), ftp (file transfer
protocol), smtp (simple news transfer protocol) and gopher.
Firewalls may be configured to control traffic under other protocol
sets, including, for example, X25, T1/E1, SMDS (Switched
Multimegabit Data Service), ISDN (Integrated Services Digital
Network) and ATM (asynchronous transfer mode). Under http various
different methods (GET, POST, etc), hosts (e.g. "x.com"), paths and
queries may all be restricted or differently treated to control
access. Under ftp various different commands (PUT, GET, etc) may be
restricted or controlled. Also, file name/type restrictions may be
applied and automatic routing of received ftp files through virus
checking may be performed. Under smtp security settings may be
based on "from" and "to" fields in an email, also, attachment types
may be restricted or controlled. Also, smtp address translation may
be performed such that a recipient of an email from within the
computer system may not see the actual end email address of the
sender, only an artificial alias of the sender, with the firewall
also performing reverse translation such that a reply to such an
email is correctly routed within the computer system.
[0217] A firewall may also provide a Network Address Translation
(NAT) service. Under NAT an IP address of a service within the
computer system is translated by the firewall into a public IP
address for that service. The public address may be a permanent IP
address always assigned to that service only, or the firewall may
hide all of the services within the computer system behind a single
public IP address. The firewall therefore alters the origin IP
address of all outgoing traffic to a relevant public IP address and
replaces the destination IP address on received traffic with the
internal IP address for a relevant service within the computer
system.
[0218] Another function which may be provided by a firewall is
malicious activity detection. This function detects malicious or
suspicious events for notification to a security administrator.
Examples of malicious or suspicious events include activity
corresponding to common forms of network attack and accesses to
unusual places within the computer system.
[0219] The functionality of a firewall may include some proxying
functions such as user authentication facilities. Users of services
to be accessed through the firewall (i.e. connections originating
in the external network and accessing some part of the computer
system) may be required to perform some form of authentication upon
passage through the firewall. Examples of services for which this
may be implemented are ftp (file transfer protocol), http
(hypertext transfer protocol), TELNET and RLOGIN. Authentication
may take place on a user basis (each individual user connecting to
the computer system is authenticated separately), a client basis
(each IP address from which access is requested is authenticated
for all accesses from that IP address) or a session basis (each
session is authenticated separately regardless of individual user
or origin IP address). The authentication process may be
transparent whereby the end user is unaware of the authentication
process, or may require the end user too actively perform
authentication steps.
[0220] Although not strictly speaking a firewall function, there is
in increasing trend for firewalls to be integrated with virtual
private networking (VPN) servers. VPN provides an facility for
secure communications across an open (non-secure) network
connection.
[0221] Any combination of the above described and other functions
may be performed by a given instance of a firewall. Individual
combinations of features may be provided or selected in dependence
upon the level of protection required, the type of traffic to be
handles and the anticipated risk of attack. The most powerful and
versatile firewalls are typically configured to be able to control
all aspects of access to and from a computer system under all
communications protocols which may be used for such access.
[0222] In the context of the above description of a modular
computer system based around a shelf 41, a processing cartridge may
be configured to perform a firewall function. This may be achieved
by installing firewall software onto a generic processing cartridge
43, or alternatively by providing a specialist hardware processing
cartridge also installed with firewall software. A further
alternative may have firewall functionality instructions provided
in firmware. However, the information processing cartridge 43 may
typically be overspecified for the performance of such a function
and so a specific hardware solution may be used. Examples of
dedicated hardware processing cartridges are shown in FIGS. 19 and
20. Such dedicated processing cartridges, when programmed with an
operating system and appropriate application software, may be
referred to as appliance processing cartridges, appliance blades,
or appliances.
[0223] FIG. 19 shows a processing subsystem for a dedicated
hardware processing cartridge based around an x86 compatible
processor such as an Intel Pentium.TM. or Celeron.TM. series
processor, or an AMD Athlon.TM. or Duron.TM. series processor. The
processor 378 is connected to a North Bridge 379 as described above
with respect to FIG. 18. The north bridge 379 provides interrupt
handling and memory management. Thus the processor 378 accesses the
memory 196 via the north bridge 379. In the present example, the
north bridge 379 communicates with the south bridge 199 via a
dedicated bridge link 605. The dedicated bridge link 605 provides a
dedicated high speed link between the south bridge (which handles
most I/O tasks and the PCI bus) and the north bridge (which handles
memory management and interrupt control). A number of dedicated
bridge link technologies exist, many of which are proprietary to a
particular chipset manufacturer. Examples of dedicated bridge link
technologies include V-Link.TM. from VIA Technologies Inc. and
MuTIOL.TM. from Silicon Integrated Systems Corporation (SIS).
Alternatively, the bridge to bridge link could be performed by a
PCI bus link.
[0224] The south bridge 199 handles the PCI bus 198, which in the
present example connects the south bridge 199 to a dual Ethernet
interface with integrated SERDES (serialiser/deserialiser) 610
which provides the network connections to the switches 73 of the
CSSPs 71 via the cartridge midplane connector 120. The south bridge
199 also connects with a Super IO device 617 via an LPC (low pin
count) bus 615. The super IO device 617 provides an interface to a
flash memory 619. The flash memory 619 stores the operating system
and application software for the processing cartridge. The south
bridge 199 also has an XBus interface to an XBus 200 which links
the south bridge 199 to the blade service controller (BSC 203). The
BSC operates as described above with reference to FIG. 11 and
therefore will not be described again here.
[0225] Other components differing from FIG. 11 include the fact
that the boot information formerly stored in a PROM attached to the
XBus is in the present example stored in the Flash memory 619,
which may be accessed by the BSC 203 via a serial link 206 to the
Super IO device 617. Also, the clock generation is, in the present
example performed by a clock generation module 193 attached to the
I2C link 197 from the south bridge 199. All other components may
behave as described above with reference to FIG. 11.
[0226] Thus FIG. 19 shows the main functional components of a first
example of a dedicated appliance blade. A further example of a
dedicated appliance blade is shown in FIG. 20.
[0227] FIG. 20 shows an example of a processing subsystem for a
dedicated hardware processing cartridge based around a PowerPC
series processor. The processor 710 connects directly to the PCI
bus 198 to connect to the dual Ethernet interface with integrated
SERDES 610 which provides network connections to the switches 73 of
the CSSPs 71. Also connected to the processor 710 is the random
access memory 196. The processor 710 also has direct access to a
flash memory 619 which is used to store the boot information,
operating system and application software for the processing
cartridge. The processor is directly linked to the BSC 203 via XBus
200 and serial link 206. The BSC 203 and components attached
thereto may operate as the like components described with reference
to FIG. 11 above and therefore will not be described again.
[0228] Thus FIG. 20 shows the main functional components of a
second example of a dedicated appliance blade. As will be
appreciated, other blade components groups and arrangements may be
provided for processing cartridges based on the above or
alternative central processors.
[0229] A processing cartridge (whether of the type describe with
respect to FIGS. 11, 18, 19 or 20 or any other type) may be
configured as a firewall module and received within a computer
system shelf 41 along with other processing modules. The firewall
module therefore is provided with all of the above described
benefits of such a computer system arrangement. In particular, the
firewall module is served by the same management and control
entities as other modules received in the same chassis 47, thus
failure of the firewall module may be immediately reported to all
other modules to cause those modules to take mitigating action,
such as routing traffic to an alternative firewall service,
performing a basic content filtering function internally, or
entering a defensive operation mode. Also, the firewall module is
able to use the management connections to immediately inform other
modules upon a detected possible security risk or breach so that
appropriate damage limitation actions can be performed. The
management connection also allows for automated reporting without
the use of email of detected security events, thus sidestepping
email delays in raising an alarm and fixing a problem. Also, since
all the modules within a given shelf 41 are linked by hardware
connections through the midplane 171, the firewall module is
unlikely to be accidentally disconnected from the network and there
is little scope for a connection to be made to another module of
the computer system which bypasses the firewall module and thereby
escaping proper security checking.
[0230] In order to increase the reliability of a firewall
processing cartridge, it may be advantageous to use non-standard
hardware and/or operating system software. By using a non-standard
operating system, for example an real-time operating system such as
VxWorks.TM., Lynx.TM. or QNX.TM., various benefits may be achieved.
Firstly, a less powerful cartridge processor may be required
compared to a cartridge running on Solaris.TM., Windows.TM., or
Unix.TM./Linux.TM. for example. Secondly, such real-time operating
systems are less vulnerable to common attacks on computer systems
as many such attacks are directed against mass-adopted operating
systems. Another possible advantage is that a real-time operating
system and firewall software package may require little enough
storage within the cartridge that they may be installed and run
from solid state memory such as a flash memory installed in the
cartridge such that there is no requirement for a hard disk drive
within the cartridge. Thus cheaper and simpler hardware may be
provided within a firewall cartridge relative to that provided in
the generic processing cartridge 43 described above. Of course,
such reduced software or hardware is merely optional and any
processing cartridge may be configured to perform firewall
functionality.
[0231] Thus there has now been described a modular computer system
module arranged to perform firewall operations for other computer
system modules. The firewall module may be fitted into a modular
computer system shelf along with any combination of other computer
system modules. The firewall module may serve to increase the
operating reliability, security and accessibility of the computer
system as a whole. As will be appreciated, many modifications and
equivalents to the above described arrangement may be made without
departing from the spirit and scope of the invention as defined by
the appended claims. Specific examples of some possible
modifications are presented hereafter.
[0232] Although it has been described above that a processing
cartridge configured as a firewall cartridge may be configured to
run under a real-time operating system, this is not essential and
any other operating system may be used.
[0233] As the skilled addressee will appreciate, it is not
essential that a firewall be configured only to perform firewall
functions. While the cartridge may be a dedicated unit, it may be
configured to perform additional functions, for example general
another function such as virtual private networking or network
integrity assurance.
[0234] Although the embodiments above have been described in
considerable detail, numerous variations and modifications will
become apparent to those skilled in the art once the above
disclosure is fully appreciated. It is intended that the following
claims be interpreted to embrace all such variations and
modifications.
* * * * *