U.S. patent application number 10/999812 was filed with the patent office on 2006-06-01 for disaggregated star platform management bus architecture system.
Invention is credited to Mark D. Overgaard.
Application Number | 20060114923 10/999812 |
Document ID | / |
Family ID | 36498599 |
Filed Date | 2006-06-01 |
United States Patent
Application |
20060114923 |
Kind Code |
A1 |
Overgaard; Mark D. |
June 1, 2006 |
Disaggregated star platform management bus architecture system
Abstract
A star topology platform management bus architecture and system
that provides disaggregation of the platform control element
portion and the routing element portion of a central management
controller, which provides for physical design efficiency as well
as other advantages.
Inventors: |
Overgaard; Mark D.; (Scotts
Valley, CA) |
Correspondence
Address: |
MICHAEL A. GUTH
2-2905 EAST CLIFF DRIVE
SANTA CRUZ
CA
95062
US
|
Family ID: |
36498599 |
Appl. No.: |
10/999812 |
Filed: |
November 29, 2004 |
Current U.S.
Class: |
370/425 |
Current CPC
Class: |
H04L 41/24 20130101 |
Class at
Publication: |
370/425 |
International
Class: |
H04L 12/56 20060101
H04L012/56 |
Claims
1. A platform management system comprising: a first field
replaceable unit, said first field replaceable unit comprising: a
first platform control element; a second field replaceable unit,
said second field replaceable unit comprising: a first routing
element, a third field replaceable unit, said third field
replaceable unit comprising: a second platform control element; a
fourth field replaceable unit, said fourth field replaceable unit
comprising: a second routing element; a first root segment, said
first root segment adapted to provide a communication link between
said first platform control element and said first routing element;
and a second root segment, said second root segment adapted to
provide a communication link between said second platform control
element and said second routing element.
2. The platform management system of claim 1 further comprising: a
plurality of satellite management controllers; a first plurality of
branch segments, said first plurality of branch segments adapted to
provide communication links between said first routing element and
each of said plurality of satellite management controllers; and a
second plurality of branch segments, said second plurality of
branch segments adapted to provide communication links between said
second routing element and each of said plurality of satellite
management controllers, wherein said first platform control element
and said second control element are adapted to provide central
management controller functions for said platform management
system.
3. The platform management system of claim 2 further comprising a
plurality of intelligent field replaceable units, wherein one or
more of said plurality of satellite management controllers resides
upon each of said plurality of intelligent field replaceable
units.
4. The platform management system of claim 3 wherein one or more of
said plurality of intelligent field replaceable units is a front
board, wherein the front boards are mounted in a subrack.
5. The platform management system of claim 1 wherein said first
platform control element and said second control element are
adapted to provide central management controller functions for a
plurality of field replaceable units within an electronic platform,
and wherein said first platform control element and said second
control element are adapted to provide central management
controller functions on a redundant basis.
6. The platform management system of claim 2 wherein said first
platform control element and said second control element are
adapted to provide central management controller functions on a
redundant basis.
7. The platform management system of claim 2 wherein said first
routing element is adapted to selectively route communications
between said first platform control element and one or more of said
plurality of satellite management controllers.
8. The platform management system of claim 2 wherein said first
routing element is adapted to selectively route communications
among the plurality of satellite management controllers.
9. The platform management system of claim 2 wherein said first
plurality of branch segments is segregated into a first plurality
of logical branch buses, and wherein said second plurality of
branch segments is segregated into a second plurality of logical
branch buses.
10. The platform management system of claim 9 wherein said first
routing element is adapted to selectively route communications
between said first platform control element and the satellite
management controller or controllers that are communicatively
linked to one of said first plurality of logical branch buses.
11. The platform management system of claim 9 wherein said first
routing element is adapted to selectively route communications
between the satellite management controller or controllers that are
communicatively linked to a first logical branch bus of said first
plurality of logical branch buses and the satellite management
controller or controllers that are communicatively linked to a
second logical branch bus of said first plurality of logical branch
buses.
12. The platform management system of claim 2 wherein said second
routing element is adapted to selectively route communications
between said second platform control element and one or more of
said plurality of satellite management controllers.
13. The platform management system of claim 2 wherein said second
routing element is adapted to selectively route communications
among the plurality of satellite management controllers.
14. The platform management system of claim 9 wherein said second
routing element is adapted to selectively route communications
between said second platform control element and the satellite
management controller or controllers that are communicatively
linked to one of said second plurality of logical branch buses.
15. The platform management system of claim 9 wherein said second
routing element is adapted to selectively route communications
between the satellite management controller or controllers that are
communicatively linked to a first logical branch bus of said second
plurality of logical branch buses and the satellite management
controller or controllers that are communicatively linked to a
second logical branch bus of said second plurality of logical
branch buses.
16. The platform management system of claim 4 wherein one or more
of said first, second, third and fourth field replaceable units are
mounted outside the subrack that holds the front boards.
17. A platform management system comprising: a first field
replaceable unit, said first field replaceable unit comprising a
first platform control element; a second field replaceable unit,
said second field replaceable unit comprising a first routing
element, wherein no platform control element resides upon said
second field replaceable unit; and a first root segment, said first
root segment adapted to provide a communication link between said
first platform control element and said first routing element.
18. The platform management system of claim 17 further comprising:
a plurality of satellite management controllers; and a plurality of
branch segments, said plurality of branch segments adapted to
provide communication links between said first routing element and
each of said plurality of satellite management controllers, wherein
said first platform control element is adapted to provide central
management controller functions for said platform management
system.
19. The platform management system of claim 18 further comprising a
plurality of intelligent field replaceable units, wherein one or
more of said plurality of satellite management controllers resides
on each of said plurality of intelligent field replaceable
units.
20. The platform management system of claim 19 wherein one or more
of said plurality of intelligent field replaceable units is a front
board, wherein the front boards are mounted in a subrack.
21. The platform management system of claim 18 wherein said first
routing element is adapted to selectively route communications
between said first platform control element and one or more of said
plurality of satellite management controllers.
22. The platform management system of claim 18 wherein said first
routing element is adapted to selectively route communications
among the plurality of satellite management controllers.
23. The platform management system of claim 18 wherein said first
plurality of branch segments is segregated into a first plurality
of logical branch buses.
24. The platform management system of claim 23 wherein said first
routing element is adapted to selectively route communications
between said first platform control element and the satellite
management controller or controllers that are communicatively
linked to one of said first plurality of logical branch buses.
25. The platform management system of claim 23 wherein said first
routing element is adapted to selectively route communications
between the satellite management controller or controllers that are
communicatively linked to a first logical branch bus of said first
plurality of logical branch buses and the satellite management
controller or controllers that are communicatively linked to a
second logical branch bus of said first plurality of logical branch
buses.
26. The platform management system of claim 20 wherein one or more
of said first and second field replaceable units are mounted
outside the subrack that holds the front boards.
27. A platform management system comprising: a first field
replaceable unit, said first field replaceable unit comprising a
first platform control element; and a second field replaceable
unit, said second field replaceable unit comprising a first routing
element; a third field replaceable unit, said third field
replaceable unit comprising a second routing element; a first root
segment, said first root segment adapted to provide a communication
link between said first platform control element and said first
routing element; and a second root segment, said second root
segment adapted to provide a communication link between said first
platform control element and said second routing element.
28. The platform management system of claim 27 further comprising:
a plurality of satellite management controllers, a first plurality
of branch segments, said first plurality of branch segments adapted
to provide communication links between said first routing element
and each of said plurality of satellite management controllers; and
a second plurality of branch segments, said second plurality of
branch segments adapted to provide communication links between said
second routing element and each of said plurality of satellite
management controllers, wherein said first platform control element
is adapted to provide central management controller functions for
said platform management system.
29. The platform management system of claim 28 wherein each
satellite management controller comprises two ports, and wherein
each satellite management controller is communicatively linked to
one of the first plurality of branch segments via a first port and
to one of the second plurality of branch segments via a second
port.
30. The platform management system of claim 28 further comprising a
plurality of intelligent field replaceable units, wherein one or
more of said plurality of satellite management controllers resides
on each of said plurality of intelligent field replaceable
units.
31. The platform management system of claim 30 wherein one or more
of said plurality of intelligent field replaceable units is a front
board, wherein the front boards are mounted in a subrack.
32. The platform management system of claim 28 wherein said first
routing element is adapted to selectively route communications
between said first platform control element and one or more of said
plurality of satellite management controllers.
33. The platform management system of claim 28 wherein said first
routing element is adapted to selectively route communications
among the plurality of satellite management controllers.
34. The platform management system of claim 28 wherein said second
routing element is adapted to selectively route communications
between said first platform control element and one or more of said
plurality of satellite management controllers.
35. The platform management system of claim 28 wherein said second
routing element is adapted to selectively route communications
among the plurality of satellite management controllers.
36. The platform management system of claim 28 wherein said first
plurality of branch segments are segregated into a first plurality
of logical branch buses.
37. The platform management system of claim 28 wherein said second
plurality of branch segments are segregated into a second plurality
of logical branch buses.
38. The platform management system of claim 36 wherein said first
routing element is adapted to selectively route communications
between said first platform control element and the satellite
management controller or controllers that are communicatively
linked to one of said first plurality of logical branch buses.
39. The platform management system of claim 36 wherein said first
routing element is adapted to selectively route communications
between the satellite management controller or controllers that are
communicatively linked to a first logical branch bus of said first
plurality of logical branch buses and the satellite management
controller or controllers that are communicatively linked to a
second logical branch bus of said first plurality of logical branch
buses.
40. The platform management system of claim 37 wherein said second
routing element is adapted to selectively route communications
between said first platform control element and the satellite
management controller or controllers that are communicatively
linked to one or more of said second plurality of logical branch
buses.
41. The platform management system of claim 37 wherein said second
routing element is adapted to selectively route communications
between the satellite management controller or controllers that are
communicatively linked to a first logical branch bus of said second
plurality of logical branch buses and the satellite management
controller or controllers that are communicatively linked to a
second logical branch bus of said second plurality of logical
branch buses.
42. The platform management system of claim 31 wherein one or more
of said first, second and third field replaceable unit are mounted
outside the subrack that holds the front boards.
43. The platform management system of claim 27 further comprising:
a fourth field replaceable unit, said fourth field replaceable unit
comprising a second platform control element a third root segment,
said third root segment adapted to provide a communication link
between said second platform control element and said first routing
element; and a fourth root segment, said fourth root segment
adapted to provide a communication link between said second
platform control element and said second routing element.
44. The platform management system of claim 28 further comprising:
a fourth field replaceable unit, said fourth field replaceable unit
comprising a second platform control element a third root segment,
said third root segment adapted to provide a communication link
between said second platform control element and said first routing
element; and a fourth root segment, said fourth root segment
adapted to provide a communication link between said second
platform control element and said second routing element, wherein
said first platform control element and said second platform
control element are adapted to provide central management
controller functions for said platform management system.
45. The platform management system of claim 44, wherein said first
platform control element and said second platform control element
are adapted to provide central management controller functions on a
redundant basis.
46. A platform management system comprising: a first field
replaceable unit, said first field replaceable unit comprising a
first platform control element; a second field replaceable unit,
said second field replaceable unit comprising a second platform
control element a third field replaceable unit, said third field
replaceable unit comprising a first routing element; a fourth field
replaceable unit, said fourth field replaceable unit comprising a
second routing element; a fifth field replaceable unit, said fifth
field replaceable unit comprising a third routing element; a sixth
field replaceable unit, said sixth field replaceable unit
comprising a fourth routing element; a first root segment, said
first root segment adapted to provide a communication link between
said first platform control element and said first routing element;
a second root segment, said second root segment adapted to provide
a communication link between said first platform control element
and said second routing element; a third root segment, said third
root segment adapted to provide a communication link between said
second platform control element and said third routing element; and
a fourth root segment, said fourth root segment adapted to provide
a communication link between said second platform control element
and said fourth routing element.
47. The platform management system of claim 46 further comprising:
a plurality of satellite management controllers; a first plurality
of branch segments, said first plurality of branch segments adapted
to provide communication links between said first routing element
and each of said plurality of satellite management controllers; a
second plurality of branch segments, said second plurality of
branch segment adapted to provide communication links between said
second routing element and each of said plurality of satellite
management controllers; a third plurality of branch segments, said
third plurality of branch segments adapted to provide communication
links between said third routing element and each of said plurality
of satellite management controllers; and a fourth plurality of
branch segments, said fourth plurality of branch segments adapted
to provide communication links between said fourth routing element
and each of said plurality of satellite management controllers,
wherein said first platform control element and said second
platform control element are adapted to provide central management
controller functions for said platform management system.
48. The platform management system of claim 47 wherein said first
platform control element and said second control element are
adapted to provide central management controller functions on a
redundant basis.
49. The platform management system of claim 47 wherein said first
routing element is adapted to selectively route communications
between said first platform control element and one or more of said
plurality of satellite management controllers.
50. The platform management system of claim 47 wherein said second
routing element is adapted to selectively route communications
between said first platform control element and one or more of said
plurality of satellite management controllers.
51. The platform management system of claim 47 wherein said third
routing element is adapted to selectively route communications
between said second platform control element and one or more of
said plurality of satellite management controllers.
52. The platform management system of claim 47 wherein said fourth
routing element is adapted to selectively route communications
between said second platform control element and one or more of
said plurality of satellite management controllers.
53. The platform management system of claim 47 wherein each
satellite management controller comprises two ports, wherein said
first plurality of branch segments and said third plurality of
branch segments link to a first port of said plurality of satellite
management controllers.
54. The platform management system of claim 53 wherein each
satellite management controller comprises two branch bus ports, and
wherein said second plurality of branch segments and said fourth
plurality of branch segments link to a second port of said
plurality of satellite management controllers.
55. The platform management system of claim 47 further comprising a
plurality of intelligent field replaceable units, wherein one or
more of said plurality of satellite management controllers resides
on each of said plurality of intelligent field replaceable
units.
56. The platform management system of claim 55 wherein one or more
of said plurality of intelligent field replaceable units is a front
board, wherein the front boards are mounted in the subrack.
57. The platform management system of claim 56 wherein one or more
of said first, second, third, fourth, fifth and sixth field
replaceable units are mounted outside the subrack that holds the
front boards.
58. The platform management system of claim 47 wherein said first
platform control element and said second platform control element
are adapted to provide central management controller functions on a
redundant basis.
59. The platform management system of claim 58 wherein said first
plurality of branch segments and said third plurality of branch
segments are segregated into a first plurality of logical branch
buses.
60. The platform management system of claim 59 wherein said second
plurality of branch segments and said fourth plurality of branch
segments are segregated into a second plurality of logical branch
buses
61. The platform management system of claim 59 wherein said first
routing element is adapted to selectively route communications
between said first platform control element and the satellite
management controller or controllers linked to one or more of said
first plurality of logical branch buses.
62. The platform management system of claim 60 wherein said second
routing element is adapted to selectively route communications
between said first platform control element and the satellite
management controller or controllers linked to one or more of said
second plurality of logical branch buses.
63. The platform management system of claim 59 wherein said third
routing element is adapted to selectively route communications
between said second platform control element and the satellite
management controller or controllers linked to one or more of said
first plurality of logical branch buses.
64. The platform management system of claim 60 wherein said fourth
routing element is adapted to selectively route communications
between said second platform control element and the satellite
management controller or controllers linked to one or more of said
second plurality of logical branch buses.
65. The platform management system of claim 59 wherein said first
routing element is adapted to selectively route communications
among the satellite management controller or controllers that are
communicatively linked to a first logical branch bus of said first
plurality of logical branch buses and the satellite management
controller or controllers that are communicatively linked to a
second logical branch bus of said first plurality of logical branch
buses.
66. The platform management system of claim 60 wherein said second
routing element is adapted to selectively route communications
among the satellite management controller or controllers that are
communicatively linked to a first logical branch bus of said second
plurality of logical branch buses and the satellite management
controller or controllers that are communicatively linked to a
second logical branch bus of said second plurality of logical
branch buses.
67. The platform management system of claim 59 wherein said third
routing element is adapted to selectively route communications
among the satellite management controller or controllers that are
communicatively linked to a first logical branch bus of said first
plurality of logical branch buses and the satellite management
controller or controllers that are communicatively linked to a
second logical branch bus of said first plurality of logical branch
buses.
68. The platform management system of claim 60 wherein said fourth
routing element is adapted to selectively route communications
among the satellite management controller or controllers that are
communicatively linked to a first logical branch bus of said second
plurality of logical branch buses and the satellite management
controller or controllers that are communicatively linked to a
second logical branch bus of said second plurality of logical
branch buses.
69. The platform management system of claim 47 wherein one or more
of said first, second, third and fourth routing elements are
adapted to selectively route communications among the plurality of
satellite management controllers.
70. A platform management system comprising: a first field
replaceable unit, said first field replaceable unit comprising a
first platform control element; and a second field replaceable
unit, said second field replaceable unit comprising a first routing
element; a third field replaceable unit, said third field
replaceable unit comprising a second routing element; a first root
segment, said first root segment adapted to provide a communication
link between said first platform control element and said first
routing element; a second root segment, said second root segment
adapted to provide a communication link between said first platform
control element and said second routing element; a first plurality
of satellite management controllers; a second plurality of
satellite management controllers; a first plurality of branch
segments, said first plurality of branch segments adapted to
provide communication links between said first routing element and
each of said first plurality of satellite management controllers;
and a second plurality of branch segments, said second plurality of
branch segments adapted to provide communication links between said
second routing element and each of said second plurality of
satellite management controllers, wherein said first platform
control element is adapted to provide central management controller
functions for said platform management system.
Description
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of
platform management systems, and more specifically to a
disaggregated star platform management bus architecture.
[0003] 2. Description of Related Art
[0004] Computers and other electronic systems often include
features with the ability to monitor and control the health and
operation of the system hardware. These features may be referred to
as platform management, system management, hardware management,
etc. Platform management features may include the monitoring and
control of temperatures, voltages, fans, power supplies, and other
features. Platform management may also include the identification
of failed hardware components.
[0005] One widely used framework for platform management is the
Intelligent Platform Management Interface (IPMI), which specifies
key agents involved as well as command sets and data formats for
sensors, event logs and sensor data record access, as well as
inventory information regarding the Field Replaceable Units (FRUs)
that comprise a system.
[0006] A platform management system is typically composed of
hardware, firmware, and software embedded within an electronic
system for the purpose of monitoring and control of the system's
operation. This management is typically performed independently of
the main processor(s) and operating system of the system. One of
the components that may be used to control platform management
functions is a central management controller. A central management
controller may be based on a microprocessor, application specific
integrated circuit, or other type of processing unit and is the
principal platform management entity in a system. (In IPMI, the
central management controller is referred to as the baseboard
management controller.) The central management controller may work
with satellite management controllers in the system, some of them
integrated on independent FRUs. When an FRU incorporates a
satellite management controller, it is referred to as an
intelligent FRU. The central management controller can monitor a
myriad of operational aspects affecting or detailing the health of
the system through any one or more of the satellite management
controllers. Typically, each of the intelligent FRUs, including
front boards, in a chassis or shelf has a satellite management
controller, each of which is in communication with sensors and
other components used to monitor and control devices on that FRU or
on other FRUs it represents. Another typical responsibility of a
central management controller is to represent the chassis or shelf
and its constituent FRUs to higher level management entities, often
via a network (perhaps Ethernet) link. "Shelf" is often used in the
telecommunications industry instead of the more familiar term
"chassis".
[0007] Typical prior art platform management control applications
utilize a single physical bus--Intelligent Platform Management Bus
(IPMB) in IPMI contexts--to link the central management controller
with any satellite management controllers in the system. In such
single bus systems, all of the communications sent to any of the
satellite management controllers are sent to all controllers that
are communicatively linked to the physical bus. An advantage of a
single physical bus is economy; with only one physical bus, one
does not need to route isolated communication lines to each of
satellite management controllers but can instead utilize common
communication lines with shared access by all management
controllers.
[0008] In United States Patent Application Publications US
2003/0152074 A1, to Hawkins et al., entitled "Switched Platform
Management Architecture and Related Methods", and US 2003/0130969
A1, to Hawkins et al., entitled "Star Intelligent Platform
Management Bus Topology", a star topology with multiple logical
buses is introduced. This approach utilizes physically disparate
interconnect segments to each set of one or more satellite
management controllers such that each set is communicatively
isolated from the other sets. Although this approach provides some
fault tolerance and other benefits, the star topology has a
distinct disadvantage of requiring the routing of many wires, which
comprise the multiple logical buses, from the board upon which the
central management controller is located. This disadvantage can be
especially important in the context of standardized modular
platforms, where most of the pins available on a board may be
allocated to specific purposes and insufficient in number to handle
that many signals.
SUMMARY
[0009] A star topology platform management bus architecture and
system that provides disaggregation of the platform control element
portion and the routing element portion of a central management
controller provides for physical design efficiency as well as other
advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a block diagram of a conventional intelligent
platform management bus (IPMB) architecture.
[0011] FIG. 2 is a block diagram illustrating a star intelligent
platform management bus (IPMB) architecture.
[0012] FIG. 3 is a block diagram illustrating a disaggregated star
platform management bus system according to an embodiment of the
present invention.
[0013] FIG. 4 is a block diagram illustrating the platform control
element and routing element of a disaggregated star platform
management bus system according to an embodiment of the present
invention.
[0014] FIG. 5 illustrates a disaggregated star platform management
bus system utilizing a single platform control element and a single
routing element according to an embodiment of the present
invention.
[0015] FIG. 6 illustrates a disaggregated star platform management
bus system utilizing dual platform control elements and two routing
elements according to an embodiment of the present invention.
[0016] FIG. 7 illustrates a disaggregated star platform management
bus system utilizing a single platform control element and two
routing elements according to an embodiment of the present
invention.
[0017] FIG. 8 illustrates a partial side view of a board mounted in
a shelf according to one embodiment of the present invention.
[0018] FIG. 9 illustrates a front view of a shelf according to some
embodiments of the present invention.
[0019] FIG. 10 illustrates a disaggregated star platform management
bus system utilizing two platform control elements and two routing
elements according to an embodiment of the present invention.
[0020] FIG. 11 illustrates a disaggregated star platform management
bus system utilizing two platform control elements and four routing
elements according to an embodiment of the present invention.
[0021] FIG. 12 illustrates a disaggregated star platform management
bus system according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0022] FIG. 1 illustrates an example of a conventional IPMB
architecture 120. IPMB (current version 1.0, revision 1.0, Nov. 15,
1999, published by Intel Corporation, Hewlett-Packard Corporation,
NEC Corporation, and Dell Computer Corporation) is the main means
for in-system platform management information exchange among
management controllers in the IPMI architecture. The current
versions of the IPMI specification are 1) version 1.5, revision
1.1, Feb. 20, 2002 and 2) version 2.0, revision 1.0, Feb. 12, 2004;
both are published by Intel Corporation, Hewlett-Packard
Corporation, NEC Corporation, and Dell Computer Corporation. In
this example, a central management controller (central MC) 121 is
communicatively linked to a plurality of satellite management
controllers (satellite MCs) 123, 124, 125 via a single intelligent
platform management bus (IPMB) 122. Although three satellite
control elements are illustrated here, it is understood that any
number of such satellite management controllers may be present
utilizing this architecture. The IPMB 122 is typically an
addressable serial bus. In the conventional IPMI architecture, a
single physical bus is used. With such a single physical bus
approach, a single logical bus is used, as well. The IPMB 122 is
used to communicate with all of the satellite MCs 123, 124, 125 and
thus each of the satellite MCs receives all of the communications
directed to any of the satellite MCs.
[0023] A platform management system may perform tasks such as
sending and receiving platform management information, controlling
platform management functions, and recording platform management
information. For example, a platform management system may receive
and log an indication from a temperature sensor that it is sensing
a temperature above a configured threshold, and in response, may
send a command to increase fan speed.
[0024] One of the controllers in a system may perform the role of
the central management controller for the system, in which case it
may perform central system management functions such as logging
events, collecting field replaceable unit (FRU) inventory
information, etc. In addition to these system-internal
responsibilities, a central management controller may be
responsible to represent the system to higher level management
entities, typically via a network link. In conventional IPMI
terminology, the central management controller for a system is
usually referred to as the baseboard management controller (BMC)
for the system. In the modular platform architectures according to
some embodiments of the present invention, "central" is a more
appropriate adjective because there may be no single "baseboard" as
might be present in a conventional server. In some embodiments,
redundancies are built into the system resulting in more than one
CMC in a system. It is common for a system to have only one active
central management controller. Non-central management controllers
may be referenced as satellite management controllers (SMCs). An
SMC may perform platform management for a particular part or
feature of a system. For example, a system may contain a number of
circuit boards and other components that are connected by buses,
with one board containing a central management controller for that
system and other boards containing SMCs. SMCs are typically
resident on FRUs, which include front boards and other types of
components.
[0025] In the IPMI-based IPMB configuration 120 the central MC 121
typically monitors a variety of management functions for the
electronic platform in which it resides. The satellite MCs 123,
124, 125 may reside on different boards within an electronic
chassis. Each satellite MC may itself provide communication links
to various control and monitoring devices for the board on which it
resides.
[0026] FIG. 2 illustrates an example of a star intelligent platform
management bus (IPMB) architecture 220. Instead of a single
physical IPMB communicatively linking the central MC to all of the
satellite MCs, each of the satellite MCs 222, 223, 224, 225, has an
independent physical bus segment 226, 227, 228, 229 which
communicatively links it to the central MC 221. The independent
physical nature of these bus segments allows for fault isolation.
The independent physical bus architecture allows any one of the
independent physical bus segments 226, 227, 228, 229 to be operated
as an independent logical bus. Embodiments utilizing an independent
logical bus architecture allow various features in addition to
fault isolation. For instance, message content on one logical bus
can be isolated from message content on another logical bus, thus
enhancing security. This may be important if intelligent FRUs on
different logical buses have different owners. Nevertheless, the
combination of the logical buses can be operated conceptually as a
single architectural bus that plays the same architectural role for
platform management as the single physical IPMB 122 of FIG. 1.
[0027] In some embodiments of the present invention, as seen in
FIG. 3, a platform management system 320 includes a platform
control element 321. The platform control element 321 is
communicatively linked with a routing element 323 via a root
segment 322. The demarcation line 328 illustrates the
disaggregation of the platform control element 321 and the routing
element 323. The platform control element 321 resides upon a field
replaceable unit (FRU) in some embodiments. In some embodiments,
the FRU upon which the platform control element resides is a front
board. The routing element 323 resides off of the FRU upon which
the platform control element 321 resides. The routing element 323
is communicatively linked to satellite MCs 325, 327 via branch
segments 324, 326. There may be any number of satellite MCs in some
embodiments. The demarcation line 329 illustrates how the satellite
MCs reside on other FRUs, such as front boards, in some
embodiments.
[0028] In some embodiments, the platform management system 320
resides within an electronic platform compliant to one or more open
architectures for modular platforms, such as those developed by the
PCI Industrial Computer Manufacturers Group (PICMG).
[0029] One such open modular architecture is PICMG 3.0, the
Advanced Telecommunications Computing Architecture (AdvancedTCA or
ACTA) specification, revision 1.0, as approved on Dec. 30, 2002,
and amended by Engineering Change Notice 3.0-1.0-001 (21 Jan.
2004). The basic elements of a PICMG 3.0 platform are front boards,
rear transition modules (RTMs), the backplane, and the subrack,
along with other shelf-specific FRUs. On the front board, three
connector zones are defined: zone 1 for power and shelf management
connections; zone 2 for Data Transport Interface; and zone 3 for
user-defined Input/Output (I/O) interconnect. Front boards plug
into slots on the backplane that contain corresponding connectors
in one or more of these zones. The subrack provides standardized
mechanical support elements for the slots, such as guide rails and
alignment pins.
[0030] Another such architecture is PICMG 2.5x, the Compact
Telecommunications Computing Architecture (CompactTCA or cTCA)
specification, currently in development and available in draft form
as revision 0.80. PICMG 2.5x platforms have the same basic elements
as PICMG 3.0 platforms (including front boards, rear transition
modules, the backplane and the subrack, plus other shelf-specific
FRUs), but there are many differences in detail. The CompactTCA
connectors most relevant to this application are P1 and P2 on
boards (referenced as J1 and J2 at the corresponding backplane
positions). Management-oriented pins are primarily in P1, with
potential for P2 usage as well. One key difference between the
CompactTCA and ATCA PICMG telecommunications computing
architectures is in the topology for the main IPMB, which is
referenced in both architectures as IPMB-0. AdvancedTCA uses a
duplex IPMB-0 comprising two architectural buses IPMB-A and IPMB-B,
while CompactTCA uses a simplex IPMB-0 comprising a single
architectural bus IPMB-A.
[0031] In both the AdvancedTCA and CompactTCA frameworks, the
central management controller function of the present invention,
which includes both a platform control element and a routing
element, is referred to as the "shelf manager".
[0032] For purposes of this application, CompactTCA is very similar
to a combination of two predecessor specifications: PICMG 2.16, the
CompactPCI Packet Switched Backplane specification and PICMG 2.9,
the CompactPCI System Management specification. References to
CompactTCA can be assumed to refer to the predecessor
specifications also, unless otherwise indicated.
[0033] Additionally, PICMG AMC.0, the Advanced Mezzanine Card
(AdvancedMC) specification, defines a hot-swappable mezzanine FRU
format for AdvancedTCA carrier boards. The main relevance of the
AdvancedMC specification to the present invention is the use of an
AdvancedMC mezzanine as a standardized FRU on which to implement
the platform control element as an additional way to take advantage
of the flexibility offered by disaggregation of star platform
management bus architectures.
[0034] In some embodiments, the platform control element 321
resides upon an FRU. In some embodiments, the FRU upon which the
platform control element 321 resides is in an FRU position
dedicated to that purpose and located outside the subrack that
contains the standardized front board positions and which is
therefore essentially free of specification constraints regarding
form factor and connector attachments to the backplane. In some
embodiments, the FRU upon which the platform control element 321
resides is a front board, thereby inheriting the constraints on
front boards imposed by the relevant specification. Alternatively,
in some embodiments, the platform control element could reside on
an AdvancedMC FRU installed on an AdvancedTCA front board. In this
latter case the platform control element is subject to the
constraints of both: 1) ATCA front boards that are AdvancedMC
carriers and 2) AdvancedMCs, themselves. The routing element 323
resides off of the FRU upon which the platform control element 321
resides. In some embodiments, the routing element 323 is on a
separate FRU. In some embodiments, the routing element 323 resides
in an air plenum or other shelf-specific location. In some
embodiments, the root segment 322 which communicatively links the
platform control element 321 and the routing element 323 may
consist of a pair of wires. In some embodiments, the root segment
322 which communicatively links the platform control element 321
and the routing element 323 may consist of four wires or possibly
two pairs of wires. For example, the root segment may use a
separate pair of wires for each direction of communication. The
root segment 322 may be routed through two or more of the eight
pins allocated under ACTA for connectivity on the zone 2 connector
between Ethernet hubs (base interface hubs, in ATCA terms) and
dedicated central management controller FRUs (dedicated shelf
management controllers, in ATCA terms).
[0035] In some embodiments, the branch segments 324, 326, although
physically separate, may be part of a single logical bus. In such
an embodiment, communications for any of the satellite MCs are sent
to all of the satellite MCs along each of the branch segments. In
some embodiments, there is a plurality of logical buses among the
branch segments. A first branch segment 326 may have its own
logical bus; communication sent along the branch segment in such an
embodiment may be limited to communication to and from the first
satellite MC 327. Similarly, the second branch segment 324 may have
its own logical bus, and communications sent along this logical bus
in such an embodiment may be limited to communication to and from
the second satellite MC 325. In embodiments with a plurality of
logical buses, the routing element 323 may selectively route
communications for particular satellite management controller only
via the logical bus that includes the branch segment which links
the routing element 323 and that particular satellite management
controller.
[0036] In an embodiment using a plurality of logical buses with the
platform control element residing on a front board, but with the
routing element residing off of the front board, the number of
wires required to be routed from the front board is significantly
reduced. This may be particularly advantageous as wires routed from
a front board typically route through a limited number of
connectors whose pin assignments are largely or entirely
pre-defined by industry standards. With the routing element located
off of the front board, the root segments between the platform
control element and the routing element may be routed through the
connectors, but the (typically) far more numerous branch segments
originate from a location off of the front board and therefore are
not routed en masse through these limited connector spaces. This
allows the benefits of star topology to be achieved even when the
platform control element resides on a front board, or optionally on
a front board. Thus, the central management controller can be
located very flexibly in the shelf.
[0037] FIG. 4 illustrates a configuration 350 of the platform
management system according to some embodiments of the present
invention. The platform control element 321 may consist of a
control logic portion 351, a memory portion 352, and a management
application portion 353. The platform control element 321 is
communicatively linked to the routing element 323 by the root
segment 322.
[0038] The demarcation line 328 indicates the disaggregation of the
platform control element 321 and the routing element 323. The
routing element 323 may consist of a router 354, and an I/O
interface 355. The branch segments 357, 358, 359 communicatively
link the routing element 323 to satellite MCs elsewhere in the
system.
[0039] In some embodiments of the present invention, as seen in
FIG. 5, a platform management system 500 comprises a platform
control element 502 residing upon an FRU 501. In this illustrative
embodiment, the platform control element 502 resides upon a front
board. A routing element 504 is communicatively linked to the
platform control element 502 via a root segment 503. The routing
element 504 is communicatively linked to a plurality of satellite
management controllers 513, 514, 515, 516 via a plurality of branch
segments 509a-d. The routing element 504 resides upon an FRU 510.
The satellite management controllers 513, 514, 515, 516 reside upon
on a plurality of FRUs 505, 506, 507, 508 in some embodiments. In
this illustrative embodiment, some of the FRUs 506, 507, 508 are
front boards. The number and type of FRUs may vary across platform
management applications, and the number of satellite management
controllers may vary across platform management applications. In
some embodiments, the front board 501 wherein the platform control
element 502 resides may also have a satellite control element
communicatively linked to the routing element 504. In some
embodiments, routing element 504 may include communication links to
devices other than intelligent FRUs, with platform control element
502 adapted to manage those links via root segment 503 and routing
element 504. In some such embodiments, the additional devices could
implement fan control and monitoring or temperature monitoring.
[0040] In some embodiments, the branch segments 509a-d may be part
of a single logical bus. In such an embodiment, communications for
all of the satellite MCs are sent to all of the satellite MCs along
each of the branch segments. In some embodiments, there is a
plurality of logical buses among the branch segments. A first
branch segment 509a may be its own separate logical bus;
communication sent along the branch segment in such an embodiment
may be limited to communication to and from the first satellite MC
513 which resides upon a first front board 505. Similarly, a second
branch segment 510b may be its own separate logical bus, and
communications sent along this logical bus in such an embodiment
may be limited to communication to and from the second satellite MC
514 which resides upon a second front board 506. In some
embodiments, each of the branch segments is part of a unique
logical bus. In some embodiments, there is a plurality of logical
buses, but a single logical bus may utilize more than one of the
branch segments. In embodiments using a plurality of logical branch
buses, the routing element may selectively route communications
between the platform control element and the SMCs that are
communicatively linked to a particular logical branch bus. The
routing element may also selectively route communications from the
SMCs that are communicatively linked to a first logical branch bus
to the SMCs that are communicatively linked to a second logical
branch bus.
[0041] In embodiments using a plurality of branch segments, the
opportunities for fault isolation are enhanced. If the satellite MC
on one of the physical branch segments is disrupting system
operation, that segment can be isolated so that the rest of the
shelf can return to normal operation. The disrupting satellite MC
and the FRU upon which it resides can be replaced later. This
ability to effectively repair a system disrupted by such a fault
via isolating the disruptive branch segment and satellite MC,
yields a drastic reduction in Mean Time To Repair (MTTR). The fault
isolation advantages are available regardless of whether the
physical branch segments are separated into distinct logical
buses.
[0042] In embodiments using a plurality of logical branch buses,
the system yields additional advantages. For example, the plurality
of logical branch buses allows for address isolation between
logical buses. All participants in a logical or physical IPMB must
have distinct IPMB addresses. In contrast, address assignments can
be completely independent between distinct logical buses.
[0043] Another advantage of a plurality of logical branch buses is
that bandwidth can be dedicated for each logical branch bus. A
satellite MC on a distinct logical branch bus can use the entire
bandwidth of the branch bus to communicate with the associated
routing element. Dedicated bandwidth for each satellite MC is also
a benefit in scenarios with a high volume of IPMI messages. Such
high volumes can occur when a shelf is started or a board is
hot-inserted or during periods when problems, such as high
temperatures, affect several intelligent FRUs at once and possibly
many sensors of each. Sharing a single 100 kHz IPMB for all this
messaging can significantly slow the shelf manager's ability to
receive, process, and respond to events in the shelf in such
circumstances.
[0044] Other advantages of a plurality of logical branch buses
include the use of different protocols on each logical branch bus
and message content isolation between logical branch buses.
[0045] In some embodiments, the platform management system 500 is
consistent with PICMG 2.5x or CompactTCA. Embodiments consistent
with cTCA require radial board control signals managed by the
central management controller. In such embodiments, the FRU on
which the routing element resides may also include the fan out of
the pairs of radial board control signals that CompactTCA requires,
one pair for each front board slot. The current draft CompactTCA
specification omits the concept of a central management controller
(shelf manager) on a front board, because insufficient pins are
available on a front board to route potentially tens of such
required radial board control signals from the front board to the
backplane. Using disaggregation, however, such a configuration is
feasible, with the required radial board control signals for each
front board slot all emanating from the FRU on which the routing
element resides, or another FRU communicatively linked to the
platform control element.
[0046] In some embodiments, the branch segments 509b-d are routed
to their respective satellite management controllers 514, 515, 516
via two pins in the PI connector of the front boards 506, 507, 508
and similarly to a satellite management controller on a non-front
board FRU 513 via two FRU-specific pins. As seen in FIG. 5, the
disaggregation of the platform management system 500 significantly
reduces the number of lead outs from the front board 501 via the Px
connectors.
[0047] A CompactTCA system implements a simplex IPMB-0. In the
platform management system 500 of FIG. 5, the root segment 503, the
routing element 504 and the branch segments 509a-d constitute the
simplex IPMB-0.
[0048] In some embodiments, as seen in FIG. 6, a platform
management system 700 utilizes two platform control elements and
two routing elements. A first platform control element 703 resides
upon a first FRU 701. In this illustrative embodiment, the platform
control element 703 resides upon a front board. A second platform
control element 704 resides upon second FRU 702. In this
illustrative embodiment, the platform control element 704 resides
upon a front board. In some embodiments, the first platform control
element and the second platform control element are adapted to
provide central management controller functions on a redundant
basis. In some embodiments, the platform control elements may
reside upon the same FRU.
[0049] A first routing element 706 is communicatively linked to the
first platform control element 703 via a first root segment 707.
The second routing element 718 is communicatively linked to the
second platform control element 704 via a second root segment 708.
The first routing element 706 resides upon a third FRU 705. The
second routing element 718 resides upon a fourth FRU 719. In some
embodiments, the routing elements may reside upon the same FRU.
Although the platform management system 700 has two platform
control elements 703, 704, as well as two routing elements 706,
718, this embodiment is a simplex IPMB-0 system. Each SMC (SMC 715,
for example) has a single IPMB-0 port. Thus, the two branch
segments (709b, 720b, for example) that link to a single SMC (715,
in this example) would be co-terminated at the same single port.
This embodiment is a redundant central MC system with redundant
platform control elements 703, 704, as well as redundant routing
elements 706, 718. Therefore, the IPMB-0 port of each SMC (SMC 715,
for example) is communicatively linked to both routing elements 706
and 718 and thereby to both platform control elements 703 and 704.
This redundant central MC, simplex IPMB-0 embodiment may be used in
a CompactTCA compliant system.
[0050] The first routing element 706 is communicatively linked to a
plurality of satellite management controllers 713, 714, 715, 716,
717 via a first plurality of branch segments 709a-e. The second
routing element 718 is communicatively linked to a plurality of
satellite management controllers 713, 714, 715, 716, 717 via a
second plurality of branch segments 720a-e. The satellite
management controllers reside upon on a plurality of FRUs. In this
illustrative embodiment, some of the FRUs 701, 702, 710, 711 are
front boards. One FRU 712 is not a front board in this embodiment.
The number and type of FRUs may vary across platform management
applications, and the number of satellite management controllers
may vary across platform management applications.
[0051] A satellite MC 713 resides upon the first FRU 701 upon which
the first platform control element 703 resides. A satellite MC 714
resides upon the second FRU 702 upon which the second platform
control element 704 resides. The FRUs upon which the platform
control elements reside may or may not have a satellite MC,
depending upon the application.
[0052] In some embodiments of the present invention, as seen in
FIG. 7, a platform management system 530 consists of a platform
control element 551 residing upon an FRU 550. In this illustrative
embodiment, the platform control element 551 resides upon a front
board. Two routing elements 554, 555 are communicatively linked to
the platform control element 551 via duplex root segments 552, 553.
The platform control element 551 is communicatively linked to a
first routing element 554 via a first root segment 552. The
platform control element 551 is communicatively linked to a second
routing element 555 via a second root segment 553.
[0053] The first routing element 554 is communicatively linked to a
plurality of satellite management controllers 560, 561, 562, 563
via a plurality of branch segments 559a-d. The first routing
element 554 is disaggregated from the platform control element 551.
The first routing element 554 resides upon an FRU 556. The second
routing element 555 is communicatively linked to a plurality of
satellite management controllers 560, 561, 562, 563 via a plurality
of branch segments 558a-d. The second routing element 555 is
disaggregated from the platform control element 551. The second
routing element 555 resides upon an FRU 557. In some embodiments,
the routing elements may reside upon the same FRU.
[0054] In this embodiment, there are two architectural buses, which
may be referred to as the A bus and the B bus. Typically, one of
the routing elements linked to the platform control element will be
part of the A architectural bus, while the other routing element
will be part of the B architectural bus.
[0055] In an ATCA environment, there are two architectural buses.
In such a duplex IPMB-0 system, one of the architectural buses,
with its root segment, and its associated routing element and
branch segments, is referred to as IPMB-A, and the other
architectural bus, with its root segment, and its associated
routing element and branch segments, is referred to as IPMB-B. A
satellite MC in an ATCA environment has an A port and a B port.
Using platform management system 530 as an illustrative embodiment
of an ATCA compliant system, for example, the IPMB-A root segment
552 linked to routing element 554 would communicate to the
satellite MCs 560, 561, 562, 563 using branch segments 558a-d which
are communicatively linked to the A ports of the satellite MCs.
[0056] In some embodiments, there is a plurality of logical buses
among the branch segments. Each physical branch segment may have
its own logical bus; communication sent along the logical branch
bus in such an embodiment may be limited to communication to and
from a single satellite MC. In some embodiments, there is a
plurality of logical buses, but a single logical bus may utilize
more than one of the branch segments.
[0057] In embodiments using a plurality of logical branch buses,
the routing element may selectively route communications between
the platform control element and the SMCs that are communicatively
linked to a particular logical branch bus. The routing element may
also selectively route communications from the SMCs that are
communicatively linked to a first logical branch bus to the SMCs
that are communicatively linked to a second logical branch bus.
[0058] The satellite management controllers reside upon on a
plurality of FRUs 564, 565, 566, 567. In this illustrative
embodiment, some of the FRUs 565, 566, 567 are front boards. The
number and type of FRUs may vary across platform management
applications, and the number of satellite management controllers
may vary across platform management applications. In some
embodiments, the front board 550 wherein the platform control
element 551 resides may also have a satellite management controller
communicatively linked to the first routing element 554.
[0059] In some embodiments, as seen in FIG. 8, the platform
management system 580 is utilized in an electronic platform
consistent with the PICMG ACTA or cTCA specifications. Some details
of the pictured embodiment in FIG. 8 are specific to ATCA, but the
description below covers embodiments consistent with either ATCA or
cTCA. The platform control element 502 resides upon a front board
521. The root segment consists of two or more sub-segments, a first
sub-segment 522 which routes the root segment from the platform
control element 502 to the zone 2 (ATCA) or P2 (cTCA) connector
524, and a second sub-segment 523 which routes the root segment
from the zone 2/P2 connector 524 to the switching element 504. In
some embodiments, connector 524 may be a zone 1/P1 connector. The
front board 521 is mounted to the rear transition module (RTM) 525.
In some embodiments, the routing element 504 is mounted in an air
plenum 530, typically outside the subrack. A demarcation line 532
on FIG. 8 approximates the boundary between the subrack, where the
front board 521 is mounted, and the air plenum above it.
[0060] A satellite MC 529 is mounted on the front board 521. The
satellite MC 529 is communicatively linked to the routing element
504 via a branch segment. The branch segment is comprised of at
least two sub-segments. A first branch sub-segment 590 routes the
branch bus from the satellite MC to the zone 1 (ATCA) or P1 (cTCA)
connector 526. A second branch sub-segment 531 routes the branch
segment from the zone 1/P1 connector 526 to the routing element
504. The zone 3 (ATCA) and other connector(s) (cTCA) 527 are not
utilized for platform management purposes in this embodiment.
[0061] FIG. 9 illustrates a partial front view of a shelf showing
potential mounting locations for FRUs used in platform management
according to some embodiments of the present invention. A plurality
of front boards (906, 907, 908, for example) are mounted in a shelf
in the standardized subrack area. An air plenum 910 above the
subrack 909 allows for the possible placement of FRUs 900, 901. The
FRUs may contain routing elements or platform control elements in
some embodiments. An air plenum 911 below the subrack 909 allows
for the possible placement of FRUs 902, 903. The FRUs may contain
routing elements or platform control elements in some embodiments.
FRUs 904, 905 may also be mounted along the end of the subrack and
may contain routing elements or platform control elements in some
embodiments. Space and cooling capacity for such FRUs outside the
subrack is often highly constrained. The disaggregation of routing
elements and platform control elements according to some
embodiments of the present invention can simplify meeting those
constraints.
[0062] In some embodiments of the present invention, a FRU may
itself have replaceable modules. In embodiments based on the AMC.0
specification, the replaceable modules are referred to as
AdvancedMCs, and plug into a carrier that is an AdvancedTCA board.
In some such embodiments, the platform control element resides on
an AdvancedMC, where both the AdvancedMC and its carrier board are
adapted to support that usage. In such embodiments of the present
invention, a star topology platform management bus architecture and
AdvancedMC-based platform control elements can be practical, where
otherwise this combination would likely not be practical. Other
embodiments of the present invention involving FRUs mounted on
other FRUs are possible.
[0063] In some embodiments, as seen in FIG. 10, a platform
management system 600 utilizes two platform control elements 603,
604. In this illustrative embodiment the two routing elements 605,
606 are not located on either of the FRUs upon which the platform
control elements 603, 604 are located. In some embodiments, the two
platform control elements 603, 604 reside on two separate front
boards 601, 602. In some embodiments, the platform control elements
may reside upon FRUs of another type. In some embodiments, the
platform control elements may reside upon the same FRU. A first
platform control element 604 is communicatively linked to each of
two routing elements 605, 606 via duplex root segments 622, 623. A
second platform control element 603 is communicatively linked to
each of two routing elements 605, 606 via duplex root segments 620,
621. In some embodiments, the routing elements reside upon separate
FRUs. In some embodiments, the routing elements reside upon the
same FRU. In some embodiments, the two platform control elements
603, 604 are adapted to provide central management controller
functions on a redundant basis. In some such embodiments, one of
the platform control elements is in an active mode while the other
platform control element is in a standby mode.
[0064] In this embodiment, there are two architectural buses, which
may be referred to as the A architectural bus and the B
architectural bus. Typically, one of the routing elements linked to
each of the platform control elements will be part of the A
architectural bus, while the other routing element will be part of
the B architectural bus.
[0065] In an ATCA environment, there are two architectural buses.
One of the architectural buses, with its root segment, and its
associated routing element and branch segments, is referred to as
IPMB-A, and the other architectural bus, with its root segment, and
its associated routing element and branch segments, is referred to
as IPMB-B. A satellite MC in an ATCA environment has an A port and
a B port. Using platform management system 600 as an illustrative
embodiment, for example, the IPMB-A root segment 622 linking the
first platform control element 604 to the first routing element 606
would communicate to the satellite MCs 607, 608, 609, 610, 611
using branch segments 625a-e, which are communicatively linked to
the A ports of the satellite MCs. The IPMB-A root segment 620
linking the second platform control element 603 to the first
routing element 606 would communicate to the satellite MCs 607,
608, 609, 610, 611 using branch segments 625a-e, which are
communicatively linked to the A ports of the satellite MCs.
[0066] The IPMB-B root segment 623 linking the first platform
control element 604 to the second routing element 605 would
communicate to the satellite MCs 607, 608, 609, 610, 611 using
branch segments 626a-e, which are communicatively linked to the B
ports of the satellite MCs. The IPMB-B root segment 621 linking the
second platform control element 603 to the second routing element
605 would communicate to the satellite MCs 607, 608, 609, 610, 611
using branch segments 626a-e, which are communicatively linked to
the B ports of the satellite MCs. In this embodiment, each of the
platform control elements uses the same routing element for IPMB-A
and IPMB-B, respectively; each routing element is shared by both
platform control elements for either IPMB-A or IPMB-B.
[0067] A plurality of satellite management controllers 607, 608,
609, 610, 611 reside individually on a plurality of front boards
601, 613, 614, 615, 602. Any number of such satellite management
controllers and front boards may be used in some embodiments. The
plurality of satellite management controllers 607, 608, 609, 610,
611 are communicatively linked to the routing elements 605, 606 by
a plurality of branch segments 625a-e, 626a-e. In some embodiments,
the plurality of branch segments 625a-e constitute a single first
logical bus, and the corresponding plurality of branch segments
626a-e constitute a single second logical bus. In such embodiments,
all of the communications sent to any management controllers via
the first or second logical buses are sent to all management
controllers communicatively linked to that logical bus.
[0068] In some embodiments, there is a first plurality of logical
buses among the first plurality of branch segments 625a-e, and a
second plurality of logical buses among the second plurality of
branch segments 626a-e. A first branch segment 626a may have its
own logical bus; communication sent along the logical branch bus in
such an embodiment may be limited to communication to and from the
first satellite MC 607 which resides upon a first front board 601.
Similarly, a second branch segment 626b may have its own logical
bus, and communications sent along this logical branch bus in such
an embodiment may be limited to communication to and from the
second satellite MC 608 which resides upon a second front board
613. In some embodiments, each of the branch segments of the first
plurality of branch segments 625a-e is part of a unique logical
bus. In some embodiments, each of the branch segments of the second
plurality of branch segments 626a-e is part of a unique logical
bus. In some embodiments, there is a plurality of logical buses,
but a single logical bus may utilize more than one of the branch
segments. In embodiments using a plurality of logical branch buses,
the routing element may selectively route communications between
the platform control element and the SMCs that are communicatively
linked to a particular logical branch bus. The routing element may
also selectively route communications from the SMCs that are
communicatively linked to a first logical branch bus to the SMCs
that are communicatively linked to a second logical branch bus.
[0069] In some embodiments, as seen in FIG. 11, a platform
management system 1000 utilizes two platform control elements 803,
804 and four routing elements 809, 810, 811, 812. The routing
elements 809, 810, 811, 812 reside upon FRUs 805, 806, 807, 808 in
this embodiment. In this illustrative embodiment the four routing
elements 809, 810, 811, 812 are not located on either of the FRUs
801, 802 upon which the platform control elements 803, 804 are
located. In some embodiments, the two platform control elements
803, 804 reside on two separate front boards 801, 802. In some
embodiments, the platform control elements reside upon the same
FRU. In some embodiments, two or more of the routing elements
reside upon the same FRU. In some embodiments, the platform control
elements may reside upon a FRU of another type. A first platform
control element 804 is communicatively linked to each of two
routing elements 809, 810 via duplex root segments 830, 831. A
second platform control element 803 is communicatively linked to
each of two routing elements 811, 812 via duplex root segments 832,
833. In some embodiments, both of the two platform control elements
803, 804 are adapted to provide central management controller
functions on a redundant basis. In some such embodiments, one of
the platform control elements is in an active mode while the other
platform control element is in a standby mode.
[0070] A plurality of satellite management controllers 817, 818,
819, 820 reside individually on a plurality of FRUs 813, 814, 815,
816. In this illustrative example, some of the FRUs 814, 815, 816
are front boards. Any number of such satellite management
controllers and front boards may be used in some embodiments. The
plurality of satellite management controllers 817, 818, 819, 820 is
communicatively linked to the routing elements 809, 810, 811, 812
by a plurality of branch segments. In some embodiments, the
plurality of branch segments that are communicatively linked to the
A ports of the satellite MCs is part of a first logical bus and the
plurality of branch segments that are communicatively linked to the
B ports of the satellite MCs is part of a second logical bus. In
such embodiments, all of the communications sent to and from the
routing elements and all of the satellite management controllers on
a particular logical bus are sent to all of the routing elements
and all of the satellite management controllers on that same
logical bus.
[0071] In some embodiments, there are two architectural buses,
which may be referred to as the A bus and the B bus. Typically, one
of the root segments and corresponding routing element linked to
each of the platform control elements will be part of the A
architectural bus, while the other root segment and corresponding
routing element for each of the platform control elements will be
part of the B architectural bus. In such a case, the A routing
elements, for example 809, 811, will be communicatively linked to
the A ports 817a, 818a, 819a, 820a of the satellite management
controllers, and the B routing elements, for example 810, 812 will
be communicatively linked to the B ports 817b, 818b, 819b, 820b of
the satellite management controllers.
[0072] In some embodiments, there is a plurality of logical buses
among the branch segments. Each physical branch segment may have
its own logical bus; communication sent along the branch segment in
such an embodiment may be limited to communication to and from a
single satellite MC. In some embodiments, there is a plurality of
logical buses, but a single logical bus may utilize more than one
of the branch segments. In embodiments using a plurality of logical
branch buses, the routing element may selectively route
communications between the platform control element and the SMCs
that are communicatively linked to a particular logical branch bus.
The routing element may also selectively route communications from
the SMCs that are communicatively linked to a first logical branch
bus to the SMCs that are communicatively linked to a second logical
branch bus.
[0073] In some embodiments, the satellite MCs 817, 818, 819, 820
will have an A port and a B port (4 connector pins total in some
such embodiments). In the case of four routing elements, the number
of branch segments (4 segments, 8 wires in some such embodiments)
coming into the satellite MC may exceed the number of available
ports (2 ports, 4 wires in some such embodiments). In such cases,
there may be sharing of satellite MC ports between the routing
elements. Typically, one of the routing elements linked to each of
the platform control elements will be part of the A architectural
bus, while the other routing element for each of the platform
control elements will be part of the B architectural bus. In such a
case, the A routing elements, for example 809, 811, will be
communicatively linked to the A ports 817a, 818a, 819a, 820a of the
satellite management controllers, and the B routing elements, for
example 810, 812 will be communicatively linked to the B ports
817b, 818b, 819b, 820b of the satellite management controllers. In
some embodiments, the A architectural bus from the first platform
control element will be joined with the A architectural bus from
the second platform control element at the satellite MC A port,
typically by the sharing of a connector pin by two wires (one wire
from each of the routing elements associated with that port), with
similar connections for the B architectural bus.
[0074] In some embodiments, as seen in FIG. 12, a platform
management system 1100 utilizes one platform control element and
two routing elements. A first platform control element 1102 resides
upon a first FRU 1101. In this illustrative embodiment, the
platform control element 1102 resides upon a front board. In this
embodiment, the first platform control element is adapted to
provide central management controller functions.
[0075] A first routing element 1105 is communicatively linked to
the first platform control element 1102 via a first root segment
1103. The second routing element 1106 is communicatively linked to
the first platform control element 1102 via a second root segment
1104. The first routing element 1105 resides upon a second FRU
1107. The second routing element 1106 resides upon a third FRU
1108.
[0076] The first routing element 11 05 is communicatively linked to
a plurality of satellite management controllers 1111, 1112 via a
first plurality of branch segments 1109a-b. The second routing
element 1106 is communicatively linked to a plurality of satellite
management controllers 1113, 1114 via a second plurality of branch
segments 1110a-b. The satellite management controllers reside upon
on a plurality of FRUs. In this illustrative embodiment, the FRUs
1115, 1116, 1117, 1118 are front boards. The number and type of
FRUs may vary across platform management applications, and the
number of satellite management controllers may vary across platform
management applications. In some embodiments, the platform control
element may be linked to more than one routing element. The
different routing elements may each be connected to different sets
of satellite management controllers.
[0077] As evident from the above description, a wide variety of
embodiments may be configured from the description given herein and
additional advantages and modifications will readily occur to those
skilled in the art. The invention in its broader aspects is,
therefore, not limited to the specific details and illustrative
examples shown and described. Accordingly, departures from such
details may be made without departing from the spirit or scope of
the applicant's general invention.
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