U.S. patent application number 14/815223 was filed with the patent office on 2015-11-26 for method and apparatus for circuit emulation with integrated network diagnostics and reduced form factor in large public communication networks.
The applicant listed for this patent is Hubbell Incorporated. Invention is credited to David Owen CORP, Natalie C. RAMSAY, Peter Bradley SCHMITZ.
Application Number | 20150341186 14/815223 |
Document ID | / |
Family ID | 47911203 |
Filed Date | 2015-11-26 |
United States Patent
Application |
20150341186 |
Kind Code |
A1 |
SCHMITZ; Peter Bradley ; et
al. |
November 26, 2015 |
METHOD AND APPARATUS FOR CIRCUIT EMULATION WITH INTEGRATED NETWORK
DIAGNOSTICS AND REDUCED FORM FACTOR IN LARGE PUBLIC COMMUNICATION
NETWORKS
Abstract
An multiservice access device (MAD) for Ethernet and DS1/DS3
services is provided for public communications carriers (telcos),
for example, and has a reduced form factor (e.g., Type 400 NCTE
mechanics or small enclosure), at least two 2.5 Gb/1 Gb facility
side ports, at least four full rate GigE drops, complementary RJ48C
demarcation and stub-ended DS1 cable options, integral T1 NIUs for
in-band loopback, NPRM, SPRM, AIS/AIS-CI and RAI/RAI-CI
diagnostics, lightning protection, and protection switching. The
MAD has built-in SynchE and IEEE 1588 synchronization, and Stratum
3 and incoming DS1/DS3 synchronization capabilities.
Inventors: |
SCHMITZ; Peter Bradley;
(Fairfax Station, VA) ; CORP; David Owen;
(Clifton, VA) ; RAMSAY; Natalie C.; (Herndon,
VA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hubbell Incorporated |
Shelton |
CT |
US |
|
|
Family ID: |
47911203 |
Appl. No.: |
14/815223 |
Filed: |
July 31, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13283069 |
Oct 27, 2011 |
9100208 |
|
|
14815223 |
|
|
|
|
61539730 |
Sep 27, 2011 |
|
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Current U.S.
Class: |
370/249 |
Current CPC
Class: |
H04J 3/0688 20130101;
H04L 12/40032 20130101; H04J 3/04 20130101; H04L 12/40006 20130101;
H04J 3/0638 20130101 |
International
Class: |
H04L 12/40 20060101
H04L012/40; H04J 3/06 20060101 H04J003/06; H04J 3/04 20060101
H04J003/04 |
Claims
1. A multiservice access device, comprising: a synchronous network
receiver for receiving synchronous network traffic; a plurality of
network interface debuggers integral to the multiservice access
device for generating messages related to the status of the
synchronous network; a packet processor for processing the
synchronous network traffic and messages into packetized
synchronous network data for asynchronous transmission over an
Ethernet network in a first bus format; a first bus translator for
translating the first bus format into a second bus format; an
Ethernet processor for receiving the packetized synchronous network
data in the second bus format and asynchronously transmitting the
packetized synchronous network data over Ethernet; a clock
synchronizing device for receiving clock information from a
plurality of devices and status information from the synchronous
network receiver, the network interface debuggers, and the packet
processor and determining a clock, and providing the clock to the
synchronous network receiver, the network interface debuggers, and
the packet processor, and a processor for managing the operation of
the transceiver, the packet processor, and the Ethernet processor,
wherein the processor sends and receives control information from
the Ethernet processor on a third bus interface.
Description
[0001] This application is a continuation application of U.S.
patent application Ser. No. 13/283,069, filed Oct. 27, 2011, which
claims the benefit of U.S. provisional application Ser. No.
61/539,730, filed Sep. 27, 2011, the entire contents of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a multiservice
access device for large public communication networks, and to a
method and apparatus for providing circuit emulation with
integrated network diagnostics and reduced form factor (e.g., an
Ethernet access device with TDM service, alarms and diagnostics)
for large public communication network equipment.
[0004] 2. Description of Related Art
[0005] Large public communication carriers (hereinafter "telcos")
desiring to sell a service, such as a DS1 or DS3, generally must do
so with certain performance assurances to their customers. For
example, if a circuit fails or if there are too many errors within
the delivered DS1 or DS3, telco customers may be eligible for a
partial refund of fees paid based upon the length or severity of
failure. By contrast, such performance assurances are generally not
required of large and small private networks providing DS1 and/or
DS3 over an Ethernet network. In addition to service assurances,
telcos must be able to provide services in a cost-effective manner.
A need therefore exists for improved large public communication
network equipment that provides services such as DS1 and/or
DS3.
SUMMARY OF THE INVENTION
[0006] Illustrative embodiments of the present invention provide a
multiservice access device (MAD) and method to integrate network
diagnostics (e.g., similar to diagnostics used by public
communications carriers or telcos for TDM circuits) into a simple
self-contained printed circuit board designed to match the same
telco shelf standards used for subscriber-located DS1 installations
to significantly reduce the complexity and cost of providing DS1
and/or DS3 services over Ethernet. The integrated diagnostics can
apply to other mounting configurations as well.
[0007] Further, illustrative embodiments of the present invention,
the multiservice access device (MAD) incorporates in-band
loopbacks, Network Performance Report Messages (NPRM), Supplemental
Network Performance Report Messages (SNPRM), Alarm Indication
Signal (AIS) and Remote Alarm Indication (RAI), Alarm Indication
Signal-Customer Interface (AIS-CI) and Remote Alarm
indication-Customer Interface (RAI-CI) for one or more DS1 and/or
DS3 circuits within an FPGA, for example, for use with a circuit
emulation chip and an Ethernet switch to provide a multiservice
access device. The MAD also comprises integrated Network interface
Units (NIUs) and lightning protection. Thus, the MAD is
miniaturized so that it can fit on the referenced standard
mechanics of telcos, while other similar versions of the
multiservice access device are optimized for use in relatively
small outdoor boxes for deployment on exterior telco-customer
building walls, in accordance with different illustrative
embodiments of the present invention.
[0008] In accordance with illustrative embodiments of the present
invention, the MAD has configurable synchronization options to
minimize delay, jitter and synchronization differences that can
occur when transporting DS1 and/or DS3 signals over an Ethernet
network. The configurable synchronization options can be, for
example, SynchE, IEEE 1588 synchronization, synchronization to
incoming DS1 or DS3 signals, Stratum 3 synchronization, and
Adaptive Clock Recovery.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention will be more readily understood with reference
to the illustrative embodiments thereof illustrated in the attached
drawing figures, in which:
[0010] FIG. 1 depicts a multiservice access device configured to
plug-in to existing cell site and business mountings in accordance
with an illustrative embodiment of the present invention.
[0011] FIGS. 2, 3, 4, 5 and 6 are block diagrams depicting
respective configurations using multiservice access devices in
accordance with illustrative embodiments of the present
invention.
[0012] FIG. 7 is a block diagram of a multiservice access device in
accordance with an illustrative embodiment of the present
invention.
[0013] FIG. 8 is a block diagram of a multiservice access device in
accordance with an illustrative embodiment of the present
invention.
[0014] FIG. 9 is a front view of an edge connector of a
multiservice access device in accordance with an illustrative
embodiment of the present invention.
[0015] FIG. 10 is a block diagram of a multiservice access device
with remote loopback in accordance with an illustrative embodiment
of the present invention.
[0016] FIG. 11 is a front view of a face plate of a multiservice
access device in accordance with an illustrative embodiment of the
present invention.
[0017] FIGS. 12A and 12B depict, respectively, a front view of a
face plate of a multiservice access device configured to map
pseudowire DS1s into an OC3 and corresponding example network
configuration, in accordance with an illustrative embodiment of the
present invention.
[0018] FIGS. 13A and 13B depict, respectively, a front view of a
face plate of a multiservice access device configured for DS3 to
DS3 mapping, and corresponding example network configuration, in
accordance with an illustrative embodiment of the present
invention.
[0019] FIG. 14 depicts a front view of a face plate of a
multiservice access device configured for Ethernet access, in
accordance with an illustrative embodiment of the present
invention.
[0020] Throughout the drawing figures, like reference numbers will
be understood to refer to like elements, features and
structures.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0021] In accordance with an illustrative embodiment of the present
invention, a multiservice access device (MAD) 700 is implemented as
an all-in-one Ethernet and DS1 access card 10, as shown in FIG. 1.
The card 10 has a reduced form factor (e.g., for shelf slot plug-in
capability) that provides access to both Ethernet and DS1 ports via
its front panel 12. For example, the card has Industry Standard T1
NIU or Type 400 network channel terminating equipment (NCTE) or
Smart Jack mechanics. Thus, the card-based, T1 sizing of the
multiservice access device allows it to plug into thousands of
existing cell site and business mountings and realize advantages
such as placement at subscriber sites with limited space. Although
the multiservice access device or MAD 700 is miniaturized (e.g., as
a card 10) so that it can fit on the referenced standard mechanics
of telcos, other similar versions of the multiservice access device
can be optimized for use in relatively small outdoor boxes for
deployment on exterior telco-customer building walls in accordance
with different illustrative embodiments of the present
invention
[0022] As described below (e.g., in connection with FIGS. 7 and 8),
the MAD 700 has built-in Layer 2 OAM and synchronization
capabilities, as well as twelve full-featured T1 NIUs with
GR-1089-CORE Issue 6 lightning protection and AIS-CI, RAI-CI, NPRM
and SPRM diagnostics built into a card 10 or other reduced form
factor MAD. Thus, the MAD 700 is particularly useful in large
public communication networks where other Ethernet access devices
are inadequate. For example, Circuit Emulation Service (CES)
equipment is generally supplied in a "pizza box" style rack mounted
chassis. Although this equipment usually has extensive Ethernet
diagnostic capabilities, it lacks some or most of the diagnostics
used by telcos to maintain traditional time division multiplexing
(TDM) DS1 and DS3 circuits. Telcos often install additional
equipment called Network Interface Units (NIUs) to provide these
diagnostics rather than invest in a totally different means of
centralized network management (that is, use of Ethernet
diagnostics for DS1 and DS3 circuits) to maintain their network.
The external NIUs add cost and, worse, installation complexity.
Such installations generally comprise a relay rack, power system,
wiring and shelves and network demarcation points, and therefore
are in contrast with installations in accordance with illustrative
embodiments of the present invention that employ, for example, DS1
equipment placed at a subscriber site comprising a self-contained
printed circuit board designed to match telco shelf standards for
installation in mountings or boxes with integral demarcation
jacks.
[0023] Use of Ethernet rather than traditional time division
multiplexing (TDM) is one way telcos can minimize the cost of
carrying data from one location to another. There are two other
important ways to reduce the cost of providing service. One way is
to minimize the cost of the equipment installation at a subscriber
site. Another way is to minimize the number of "truck rolls"
necessary to maintain a circuit and diagnose service problems. As
described herein, illustrative embodiments of the invention
advantageously reduce installation and truck-roll costs via (1) the
convenient plug-in operation or installation of the card 10 or
other reduced form factor MAD 700, and (2) integral NIU provide
diagnostics within the self-contained card or other reduced form
factor MAD which includes, but are not limited to, in-band loop
backs, Network Performance Report Messages (NPRM), Supplemental
Performance Report Messages (SPRM). Alarm Indication Signal (AIS).
Remote Alarm Indication (RAI), Alarm Indication Signal-Customer
Interface (AIS-CI) and Remote Alarm Indication-Customer Interface
(RAI-CI). For example, the provision of AIS-CI and RAI-CI
significantly reduces, if not prevents, "truck rolls" (i.e.,
deployment of fleet vehicles or trucks for repairs). In addition,
the diagnostics further refine information received when an alarm
signal is received by indicating, for example, an alarm signal
occurred because a subscriber unplugged the cable, in which case no
repair truck deployment is needed, or an error has occurred in a
system component, in which case a repair (e.g., "truck roll") may
be needed.
[0024] While telcos increasingly rely more on Ethernet than T1s for
data service, telcos continue to support T1s for 911 services and
legacy systems. The MAD 700 constructed in accordance with
illustrative embodiments of the present invention provides Ethernet
and T1/DS1 access, but unlike other access devices, the MAD 700
employs the referenced standard mechanics of telcos for compact and
convenient installation, as well as diagnostics on the T1 services
that other Ethernet and DS1/T1 access devices fail to provide
without reliance upon external devices.
[0025] Providing fiber to cell towers for Ethernet service has
become more practical than copper lines and often necessary to
support higher Ethernet speeds. Cell tower equipment, however,
needs lightning protection since significant voltages occur between
site equipment when lightning strikes. Ethernet access devices
generally do not have integral means to prevent service failure due
to lightning strikes. As described below, the MAD 700 constructed
in accordance with illustrative embodiments of the present
invention also provides built-in lightning protection (e.g.,
GR-1089-CORE Issue 6 DS1 Class 3a/b and 5a/b lightning
protection).
[0026] The MAD 700 constructed in accordance with illustrative
embodiments of the present invention employs SynchE, IEEE 1588 and
Stratum 3 synchronization. The MAD 700 avoids 1588/SynchE coupling
issues found in some other products that can generate wander and
prevent use in 4G networks. Timing for proper synchronization is
critical to providing "Carrier Grade" DS1 and DS3 service. The MAD
700 provides DS1 and DS3 diagnostics and timing to support such
Carrier Grade services.
[0027] With continued reference to FIG. 1, the MAD 700 (e.g., card
10) comprises at least two optical facility-side Ethernet ports 22
and 24 (e.g., small form pluggable or SFP ports labeled "NET1" and
"NET2" on the front plate 12), each capable of adapting to 2.5
Gigabit per second (Gb) or 1 Gb operation (e.g., single fiber, dual
fiber and/or conventional or course wave division multiplexing
(CWDM)). The MAD 700 also comprises four Full Rate Gigabit Ethernet
(GigE) drops, that is, two optical drops 26 and 28 (e.g., labeled
"DROP1" and "DROP2" on the face plate 12) and two electrical drops
30 and 32 (e.g., labeled "DROP3" and "DROP4" on the face plate 12),
as well as a DS1 connector 34 for supporting twelve DS1 drops. For
example, the DS1 connector has twelve 4-wire DS1 interfaces, with
each interface comprising a standard transmit pair and receive
pair. Thus, MAD 700 manages more than 8 Gb of bandwidth through a
14 Gb wirespeed switching core, described below, to support
non-blocking services, as well as robust micro-ring and daisy-chain
topologies, as described below in connection with FIGS. 5 and 6,
respectively. By managing up to 8 Gb of bandwidth, the MAD 700
(e.g., the simple all-in-one Ethernet and DS1 access card 10 shown
in FIG. 1) supports multiple generations of cell site backhaul and
evolving business service requirements.
[0028] With continued reference to FIGS. 1 and 11, LEDs or other
indicators 14, 16 and 18 corresponding to connectors 2, 24, 26 and
28 are provided for indicating conditions with respect to the card
or unit 10 itself, a DS1 and/or an Ethernet link connected thereto
(e.g., see front-panel LEDs for Ethernet, DS1 and UNIT for a quick
view of over-all operational status). The ACT LED 38 indicates
activity on the Management port (MGMT, 38) when the MGMT port is
connected to a computer to provision the unit. LEDs can be
multi-color, using red, green or yellow using different
annunciation periods to indicate different operating states,
thereby simplifying operation and reducing the size of the MAD
700.
[0029] As shown in FIG. 1, the front panel 12 of a card or other
reduced form factor MAD 700 has a DB-9, RS232 female port 20 for
access via a personal computer (PC), laptop or other computing
device, for example, that is running HyperTerminal or other VT-100
emulation program, to provide secure provisioning of DS1
parameters. This asynchronous serial port operates at 9600 baud
with 8 bits of data, no parity, no flow control, and 1 stop bit,
for example. A standard RJ45 Out of Band management port 36
provides secure provisioning of Ethernet parameters.
[0030] The SFP Ethernet ports 22 and 24 (e.g., NET1 and NET2) each
accommodate a multi-rate Ethernet SFP to operate at either a 1 Gb
or 2.5 Gb Ethernet rate. NET1, for example, can provide an
interface to the network-side facility. NET2 can provide an
interface to the network-side facility in switch-to-protect
configurations or an extension to another card 10 micro-ring or
daisy-chain applications described below with reference to FIGS. 5
and 6.
[0031] Similarly, the DROP1 and DROP2 can be SFP Ethernet ports 28
and 30, respectively, and each accommodate a 1 Gb Ethernet SFP so
that DROP1 and DROP2 can each operate at a rate of up to 1 Gb, for
example. DROP1 and DROP2 can each provide an interface to an
optical subscriber demarcation jack or, in bookend configurations
(e.g., FIG. 2), to a network switch or router.
[0032] The DROP3 and DROP4 ports 30 and 32 can each be an RJ45
10/100/1000BaseT Ethernet port. DROP3 and DROP4 can each operate at
a rate of up to 1 Gb and provide an interface to an electrical
subscriber demarcation jack or, in bookend configurations (FIG. 2),
to a network switch or router.
[0033] As shown in FIG. 2, two multiservice access devices (e.g.,
both are cards 10) are installed in an illustrative bookend
configuration at respective sites 40 and 42 such that the bandwidth
of the link 44 between them is 1 Gb to 5 Gb, depending on the 1310,
1550, CWDM or single fiber SFPs employed in the ports 22 and/or 24
of the respective cards 10. The site 40 can be, for example, a
remote terminal (RT), controlled environmental vault (CEV), hut,
building telephone room or central office (CO), and so on. The site
42 can be, for example, a cell tower or cell site suite, a closet
or other enclosure on a building rooftop or other customer premise,
or a Westell CellPak CP258 equipped with a CSSI kit (available from
Pulse Communications Inc., Herndon, Va.), among other customer
accessible demarcation points 54.
[0034] With continued reference to FIG. 2, various interfaces can
be connected to the ports 26, 28, 30, 32 and 34 (e.g., DROP1,
DROP2, DROP3 and DROP4, and DS1 on the face plate 12) of the
respective MADs 700 deployed at the sites 40 and 42. As explained
above, the DS1 connector 34 has twelve DS1 interfaces. When a MAD
700 constructed in accordance with an illustrative embodiment of
the present invention (e.g., card 10) is deployed in a mounting 46
at a site 42 such as a 3O3D3-CPL2C multi-slot TDM/IP mounting
available from Pulse Communications Inc., Herndon, Va., for
example, a cable 48 (e.g., a CPM-SG-12DS1X available from Pulse
Communications Inc.) can be used that provides 12 RJ48C bulkhead
jacks for 12 DS1 demarcation points indicated generally at 54. LC
and/or RJ45 Ethernet demarcation points are also available.
[0035] As shown in FIG. 2, a MAD 700 constructed in accordance with
an illustrative embodiment of the present invention (e.g., card 10)
at a site 42 can be deployed in a mounting 50 such as a shelf
(e.g., 2O3D3-19A two-slot TDM/IP mounting available from Pulse
Communications Inc., Herndon, Va.), and a cable 52 (e.g.,
MRJ-MSL/U50Sxxx available from Pulse Communications Inc. where
"xxx" in the part number represents the cable length in feet)
provides a stub-ended cable with separate transmit and receive
pairs. An adapter (e.g., a MRJ-MBL/TRANS adapter available from
Pulse Communications Inc.) provides a female AMP connector
interface with screw-lock strain relief hardware designed to
interface existing male 50-pin AMP connector interfaces (e.g.,
AMP-MBL/U50Sxxx cables available from Pulse Communications Inc.).
The MAD 700 (e.g., card 10) in mounting 50 can also provide 1-4 Gb
of Ethernet bandwidth as indicated at 56.
[0036] With reference to FIG. 3, sites 40 and 42 can each be
configured with a MAD 700 (e.g., card 10) and links 44a and 44b to
manage 8 Gb of bandwidth. The specific mounting is omitted from the
figure. It is to be understood that the mounting can be selected
from among a number of different types of mountings (e.g.,
different types of shelves, enclosures, and so on).
[0037] As shown in FIG. 4, a user can plug in a second card 10 to
manage 16 Gb in a -40.degree. C. to +70.degree. C. wall mounting or
one remote unit (RU) shelf. For example, a pair of MADs 700 (e.g.,
a pair of cards 10) can plug into an existing 19''/23'' rack
mounted 2O3D3-19A 1.75'' (1 U) high shelf, or a 3O3D3-CPL2C locking
wall mounting, to provide 8 Full Rate GigE drops plus 24 DS Is at
that site 40 or 42. Correspondingly, as shown in FIG. 6, the site
40 can have an aggregator 58. Adding a third card 10 at site 42
(e.g., using a daisy-chain topology, allows, for example, a 1 Gb
input 44 to provide 12 GigE drop interfaces plus 36 DS1s at 42.
[0038] A MAD 700 constructed in accordance with an illustrative
embodiment of the present invention (e.g., card 10) can be
configured to implement micro-ring and daisy-chain topologies such
that a single fiber 60, for example, can deliver dozens of DS1
ports and dozens of GigE ports (e.g., Ethernet drops such as two
RJ45 and two SFP, as indicated generally at 62 in FIG. 5), and
therefore facilitate expansion and resiliency, simple growth, and
low first costs. With reference to FIGS. 5 and 6, switch-to-protect
service is also provided by the MAD 700 in accordance with an
illustrative embodiment of the present invention, which is a
significant advantage over Ethernet access devices for private
networks that do not provide micro-ring applications since telcos
are interested in having protected Ethernet rings in much the same
way telcos are interested in having protected SONET rings.
[0039] For example, if one of the paths in a MAD 700 failed (e.g.,
card 10b in FIG. 5), Ethernet traffic can be automatically sent to
the network via another path 64. As shown in FIG. 5, a fiber 60 is
provided to the network side port 22 (e.g., a SFP Ethernet port) on
device 700a, which can manage Ethernet throughput (e.g., 2.5 Gb) to
port 22 on device 700b. In the event that a network side path
failed (e.g., in device 10b), an Ethernet switch on the device 700b
(described below) can manage Ethernet throughput (e.g., 2.5 Gb)
using the other path (e.g., via port 24) to the device 700c to
provide a path 64 back to the network. The devices 700a, 700b and
700c use, for example, ERPS with 50 ms, switch-to-protect, or RSTP
to implement redundant network pathways. Such switch-to-protect or
redundant pathways operation of the MAD 700, in accordance with an
embodiment of the present invention, represents a significant
advantage over existing suites of vendor equipment deployed, for
example, at a cell tower. Vendors' suites of equipment do not share
equipment with other vendors. Thus, to avoid loss of service due to
a network pathway being down, each suite of vendor equipment
generally has its own path back to the network (e.g., via an
external box or equipment), thereby adding to complexity and cost.
The MAD 700 constructed in accordance with an illustrative
embodiment of the present invention overcomes these disadvantages
because it can be simply a card plug-in at each vendor's suite,
thereby eliminating additional external equipment, and the Ethernet
switch (described below) in the MAD manages throughput if a fiber
is out. For example, the multiservice access devices deployed in
several vendors' suites at a cell site can communicate with each
other (e.g., using link aggregation control protocol (LACP)) to
ensure continued service when a fiber fails. For example, LACP
allows a network device such as a card 10 in one suite to negotiate
an automatic bundling of links by sending LACP packets to a peer
(e.g., a directly connected card 10 in another suite that also
implements LACP).
[0040] Thus, as illustrated in FIGS. 2 through 6, the MAD 700 in
accordance with illustrative embodiments of the present invention
provides universal and integrated topologies to leverage existing
SONET, DCS, Router and Aggregator infrastructure.
[0041] FIG. 7 illustrates a block diagram of the MAD 700 in
accordance with an illustrative embodiment of the present
invention. In the example of FIG. 7, a switch core 702 that
performs the core switching functionality is coupled to an Ethernet
PHY device 704, which provides a plurality of Small Form factor
Plugs (SFP) for networking functionality. For example, the Ethernet
device 704 interfaces with a pair of facility side SFPs (e.g., each
SFP operating at 1 or 2.5 Gb), a pair of SFPs (e.g., each operating
at 1 Gb), and a pair of RJ45s (e.g., each a 10/100/1000BT port). An
RJ45 interface for managing the MAD 700 (e.g., for local out of
band (OOB) management) is coupled to the switch core 702. The
switch core 702 is also coupled to a processor 706 that controls
the overall operations of the multiservice access switch 700. The
switch core 702 is also coupled to a Structure Agnostic TDM over
Packet (SAToP) device 708. The SAToP 708 receives synchronous
traffic from a Network Interface Unit (NIU) 710 and converts all
traffic to a packet format suitable for Ethernet transmission. For
instance, SAToP 708 may receive TDM synchronous data from a DS1 or
DS3, which must be converted into a packetized format suitable for
asynchronous Ethernet transmission.
[0042] The NIU 710 is also coupled to the processor 706 and
performs telecom diagnostics on the network. In the example of FIG.
7, the NIU 710 is integral to the MAD 700 and thereby provides
telecom diagnostics (e.g., AIS-CI, RAI-CI, NPRM, SPRM, etc.) on a
plurality of telecommunication network interfaces (DS1, DS3, etc.).
A line input unit (LIU) 712 receives the physical network traffic
and provides the received data to the NIU 710 for diagnostics and
transmission to the SAToP 708.
[0043] In the example of FIG. 7, the LIU 712 is coupled to multiple
DS1 interfaces (e.g., 12 interfaces as described in connection with
FIG. 1) via power input protection device 714 to provide power
protection to prevent service failure (e.g., a line surge or a
lightning strike). For example, in a cellular application, an
antenna of a base station may be struck by lightning due to its
height, thereby causing a brief high voltage/high current surge in
the system which may cause temporary or permanent failure of
devices in the MAD 700. Accordingly, the power input protection
device 714 is configured to handle suitable events that could cause
temporary or permanent failure based on the type of
installation.
[0044] FIG. 8 illustrates a more detailed block diagram of a MAD
700 in accordance with an illustrative embodiment of the present
invention. In the example of FIG. 8, a Field Programmable Gate
Array (FPGA) provides a plurality of functions and interfaces to
allow devices therein to communicate, thereby allowing high-level
integration to reduce the physical footprint of the MAD 700. A
processor 802 that provides the overall control of the MAD 700 is
coupled to an Ethernet processor 804, at least one transceiver 806,
and a programmable logic device (PLD) 830. Generally, the processor
802 receives status and control information from the various
devices and transmits information over the bus to control the
operation of the various devices. That is, the processor 802
generally does not receive network traffic to perform any
switching. However, the processor 802 can receive some network
information in order to perform diagnostic tests, provide
information to a user on debug interfaces, and so forth. Further,
as illustrated in FIG. 8, the processor 802 can be directly coupled
to the Ethernet processor to control its operation (e.g., generate
an interrupt, provide clock information, etc.).
[0045] In the example of FIG. 8, the transceivers 806 are
configured to send and receive data via a conventional synchronous
network such as DS via a DS1 connector 810. However, the
transceivers 806 are coupled to the DS1 connector 810 via
protection devices 812 that are configured to protect the MAD 700
from event failures as noted above. In one example, the protection
devices 812 protect the transceivers from lightning events that
generate high voltage/current for fractions of a second.
[0046] The transceivers 806 are also coupled to a FPGA device 814
that implements telecommunications diagnostics and loopback
functions. For example, the FPGA device 814 implements in-band
loopback functions that allow network diagnosis and other tools
such as AIS-CI, RAI-CI, SPRM, NPRM, and so on. The FPGA device 814
therefore performs the functions of a plurality of NIUs which, as
described in detail below, allow an operator of the MAD 700 to
configure and troubleshoot the associated network connections in a
more time efficient manner.
[0047] The FPGA device 814 is coupled to a Structure Agnostic Time
Division Multiplexing over Packet (SAToP) processor 816, which
receives and converts the network data (i.e., synchronous TDM data
from transceivers 806) into packetized Ethernet packets for an
asynchronous network. The packet processor 816 is agnostic with
regard to the structure of the input and can, for example, receive
a framed or unframed data input. The packet processor 816 outputs
the TDM over packet (TDMoP) traffic (i.e., data) via a bus
interface. The Ethernet processor 804 in conjunction with the
processor 802 assigns high priorities, as well as other parameters,
to the packetized TDM signals to help ensure that they are
transported in accordance with Carrier Grade criteria so that telco
standards can be met. The MAD 700 includes a high capacity Ethernet
processor (e.g., 14 Gb throughput in terms of the MAD 700 shown in
FIG. 1) to help avoid contention between the Structure Agnostic
Time Division Multiplexing Packets and other Ethernet signals. In
the example of FIG. 8, the packet processor 816 outputs the TDM
over packet (TDMoP) traffic (i.e., data) on a Fast Ethernet
(FE)/media independent interface (MII) bus that is received via
FPGA device 818. Generally the MII connects different types of
physical transceivers to Media Access Controllers (MAC) to thereby
allow any MAC to be used with any transceiver regardless of the
network signal transmission media (e.g., twisted pair, etc.).
[0048] However, the Ethernet processor 804 can use different bus
interfaces than the packet processor 816. For example, as noted
above, the packet processor 816 transmits and receives TDMoP
traffic over a FE/MII bus, and the Ethernet processor 804 transmits
and receives the network traffic over a Serial Gigabit MII (SGMII)
bus. Accordingly, in the example of FIG. 8, the MAD 700 includes
the FPGA device 818 to convert the MII bus data into second bus
data format such as the SGMII bus associated with the Ethernet
processor 804. Accordingly, the FPGA device 820 converts
bidirectional traffic to and from the packet processor 816 and the
Ethernet processor 804.
[0049] That is, synchronous DS1 traffic is received by a FPGA
device 814 for diagnostic purposes, converted from the TDM
synchronous format into asynchronous packets on a first bus
interface, converted from the first bus interface into a second bus
interface, and provided to the Ethernet processor 804 for suitable
routing. Similarly, for data being transmitted from the Ethernet
processor 804 via DS1, a corresponding process occurs to output the
data via one of the transceivers 806. The FPGA device 814 also
generates telecom diagnostic information to allow efficient
troubleshooting of the network. The telecom diagnostic information
is packetized and transmitted via Ethernet, thereby allowing a
network operator to more efficiently troubleshoot any network
errors associated with the synchronous network.
[0050] The Ethernet processor 804 is configured to perform the core
switching, but, as described above, the processor 802 manages the
operation of the devices in the MAD 700. Accordingly, the Ethernet
processor 804 transmits and receives control information to allow
the processor 802 to manage its operation. In the example of FIG.
8, the Ethernet processor 804 transmits and receives the management
(MGMT) traffic over a SGMII bus. However, the processor 802
transmits and receives MGMT traffic over a MII bus and the Ethernet
processor 804. Accordingly, in the example of FIG. 8, the MAD 700
includes a FPGA device 820 that converts the MII bus data into
second bus data format such as a SGMII bus. Accordingly, the FPGA
device 820 converts bidirectional traffic to and from the processor
802 and the Ethernet processor 804.
[0051] The Ethernet processor 804 is configured to communicate via
a plurality of network interfaces. In the example of FIG. 8, the
Ethernet processor communicates with four SFP ports 822 for fiber
optic networking (e.g., a pair 26 and 28 for 1 GB subscriber drops
and a second pair 22 and 24 for 1/2.5 GB network connections as
described with reference to FIG. 1) and a pair of RJ45 for GigE
subscriber drops (e.g., ports 30 and 32 in FIG. 1). Accordingly, to
accommodate such bandwidth, the Ethernet processor 804 is
configured to have substantially higher switching speed than the
sum of the four network ports 22, 24, 26 and 28 described above.
Further, as described in detail below, the Ethernet processor 804
can be configured in either daisy-chain configuration or can be
configured in a ring topology. In the example of FIG. 8, the
Ethernet processor 804 can accommodate 14 Gb of core switching.
Because the Ethernet processor's switching capability (e.g., 14 Gb)
exceeds the sum of the network connections drop provided to the
subscriber (e.g., 4 Gb), the Ethernet is generally not running at
maximum capacity, thereby allowing the Ethernet processor to avoid
contention between Ethernet signals, operate at a low temperature
and be positioned for later migration to additional ports in
subsequent implementations of the multiservice access device in
accordance with illustrative embodiments of the present invention.
The Ethernet processor 804 is also coupled to a non-volatile memory
device such as a Serial Flash memory 826 and a volatile memory such
as DDR2 828 for temporary storage (e.g, low priority packets,
etc.).
[0052] The processor 802 is further coupled to a programmable logic
device (PLD) 830, which is further coupled to output indicators 832
(e.g., LEDs, matrix displays, etc.). The PLD 832 is coupled to
multiplexer (MUX) 833, which is further coupled to the plurality of
SFP ports 822 via a bidirectional interface (e.g., I2C, etc.). The
PLD 830 receives information regarding the status of the ports and
provides fixed logic functionality regarding the status of the SFP
ports 822. For instance, the PLD 830 determines if a cable (e.g.,
available from Pulse Communications Inc.) is used in the SFP ports
822 and, if so, can determine if the cable plugged into the SFP 822
is properly terminated at the receiving device. Accordingly, the
PLD 830 cause the output indicators 832 to provide a visual display
to indicate that the network connection is properly terminated at
the receiving device.
[0053] The processor 802 is also coupled to a Clock Sync device
834, which is also coupled to the Ethernet processor 804. The Clock
Sync device receives clock instructions from the processor 802, and
exchanges clock information with Ethernet processor 804. In
particular, the Ethernet processor 804 is configured to provide a
precision time protocol such as IEEE 1588 or Synchronized Ethernet
(SynchE), and processor 802 provides instructions as well as
exchanges information from other devices in the switch 700 (e.g.,
FPGA 814, packet processor 816, etc.) regarding the status of the
synchronization of the devices in the switch 700. Synchronization
from the Ethernet processor 804 is also shared with these devices.
The synchronization operating mode is by initial default or
provisioned by the telco or user, for example, and that mode is
provided to the Clock Sync 834 as well as the Ethernet Processor
804 to determine the source of clocking, which in turn is provided
to FPGA device 814, packet processor 816, and FPGA device 818. The
Clock Sync device 834 can also receive a clock source from a
Stratum 3 clock 836 or from the incoming DS1 or DS3 signals as an
alternative to IEEE 1588 or Synchronized Ethernet (SynchE)
synchronization. In the event the devices in the MAD 700 are
unsynchronized, the operation of the DS1 or DS3 network would not
function correctly, if at all. Thus, the Clock Sync device 834 may
use several different, alternative clocking sources for
synchronization.
[0054] Thus, the MAD 700 in accordance with an illustrative
embodiment of the present invention is particularly advantageous
for telcos that provide SONET and Ethernet services. Synchronized
networks such as SONET have precise timing, whereas Ethernet
networks may have no such timing requirements. Standards and
techniques for transporting standard DS1 and/or DS3 signals over an
Ethernet network instead of a traditional Time Division
Multiplexing (TDM) network are known. In general, a synchronous DS1
signal is "packetized" for Ethernet compatibility and various means
are utilized to "reassemble" the packets into a conventional and
properly timed DS1 or DS3. Improvements to minimize delay, jitter
and synchronization differences, however, are needed. The MAD 700
constructed in accordance with an illustrative embodiment of the
present invention has configurable synchronization options to
address these issues.
[0055] Accordingly, to support telcos that provide both SONET and
Ethernet services, the MAD 700 employs SynchE, IEEE 1588,
synchronization to incoming DS1/DS3 signals and Stratum 3
synchronization capabilities, as well as Adaptive Clock Recovery
(ACR). For example, a user or telco can select one of SynchE or
IEEE 1588 via provisioning. If the telco or user equipment does not
support either SynchE or IEEE 1588, the user or telco can select
one of synchronization to incoming DS1/DS3 signals or Stratum 3
synchronization (e.g., via provisioning or default configuration);
otherwise, ACR can be used. The MAD 700 employs ITU G.824 (e.g.,
the control of jitter and wander within digital networks which are
based on the 1544 kbit/s hierarchy), ITU G.8261 (e.g., timing and
synchronization aspects in packet networks), Network Timing
Protocol Version 4 (NTPv4) to convey timekeeping information from
primary servers, as well as IEEE 1588v2 (e.g., IEEE Standard for a
Precision Clock Synchronization Protocol for Networked Measurement
and Control Systems; Precision Timing Protocol (PTP) with one or
two step clock), SynchE ITU G.8262 (e.g., timing characteristics of
synchronous Ethernet Equipment slave Clock (EEC)), and SynchE ITU
G.8264 (e.g., distribution of timing information through packet
networks).
[0056] It is noted that 4G cellular applications require very
precise timing, and certain implementations of IEEE 1588 and SynchE
may result in interaction that may preclude use in 4G networks
because of small synchronization instabilities. The configurable
synchronization of the MAD 700 described above in accordance with
an illustrative embodiment of the present invention avoids such
detrimental interaction so that use with 4G networks is
possible.
[0057] The MAD 700 also includes a first debug interface 838 for
configuring the synchronous network and a second debug interface
840 for configuring the asynchronous network. The first debug
interface 838 may be a standard D-subminiature 9 (i.e., DB9)
connector to control and configure the FPGA device 814 integral NIU
functionality that corresponds to that of conventional NIUs and
other parameters related to the synchronous network. Conventional
NIUs are individual cards (e.g., implemented in Type 400 mechanics)
that require an operator to plug into each individual NIU and
configure it manually, even if the configuration between NIUs is
identical. By contrast, an advantage is realized by an illustrative
embodiment of the present invention, wherein there are multiple,
integral NIUs implemented in the FPGA device 814, and the debug
interface 838 allows an administrator to configure one or many of
the NIUs at the same time. Thus, the administrator can quickly and
efficiently configure the NIUs in the MAD 700. Further, because
NIUs can be configured at the same time, this prevents minor
clerical errors by the administrator. Further, as stated above, the
form factor of the MAD 700 is reduced by having integral NIUs
versus having to use plural, external cards or other devices.
[0058] The second debug interface 840 is implemented using
conventional port (e.g., RJ45, USB, etc.) and is used to configure
the network configuration with respect to the asynchronous network.
As illustrated above, the administrator can configure the
arrangement of the network connections. For example, as illustrated
in FIG. 3, two MADs 700 can be configured to provide 8 Gb of data
from combined gigabit Ethernet and DS1/DS3 signals. Further, as
illustrated in FIG. 5, MADs 700 can be implemented in a ring
configuration via the second debug interface 840 or, in some cases
using LACP, the MAD 700 can configure themselves automatically.
[0059] Thus, the one or two MAD 700 can be configured to support
the following speeds and capacity: 14 Gb Wirespeed Switching Core
Speed, 8 Full Rate GigEs+24 DS1s (e.g., for Subscriber Locking Wall
Mount Enclosure capacity and rack mounted shelf capacity), latency
of 2.8.mu.sec+frame, Jumbo Frame support, a payload of 32 Full Rate
GigE circuits plus 96 DS1s per fiber pair with CWDM optics, and CO
capacity (in bookend configuration) of 160 Full Rate GigEs plus 480
DS Is in a standard 7 Ft. rack assembly.
[0060] The MAD 700 constructed in accordance with an illustrative
embodiment of the present invention has a surge-protected 24 VDC to
48 VDC input voltage range. External adapters are available for
local 120 VAC powering and remote powering. Thus, the MAD 700 can
be powered via a wide array of redundant or non-redundant powering
options such as 48 Vdc, cell-site 24 Vdc, 120 Vac via an optional
(e.g., the 2100-0300 power converter available from Pulse
Communications Inc.) or remote powering over up to 4 miles of 22 Ga
copper pairs via optional Span Power units (e.g., also available
from Pulse Communications Inc.).
[0061] The MAD 700 supports Layer 2 Carrier Ethernet such as 802.1
Q-in-Q (formerly known as 802.1ad), 802.1D MAC Bridging and Auto
Learning, 802.1Q VLAN (e.g., 8K MAC; 4K VLAN; STP, RSTP and MSTP),
Hierarchical MEF compliant policing and scheduling, MEF 6, 9, 10,
14 and 18, and VLAN Translation, MAC-based VLAN and Protocol-based
VLAN.
[0062] The MAD 700 supports Class of Service (CoS)/Quality of
Service (QoS) such as Committed and Excess Information Rate
(CIR/EIR) granularity of 64 k, CoS per port (e.g., VLAN ID (C-tag),
VLAN P-bits, MAC, DSCP), eight CoS queues per port and eight 802.1p
priorities, Multicast, Broadcast and Unicast Storm Control, RFC2698
Two Rate 3 Color Marker (tr3CM) for ingress policing, Policing by
port, service, bandwidth and queue, and Strict or deficit weighted
round robin scheduling.
[0063] Protocols used by the MAD include, but are not limited to,
SAToP (Structure-Agnostic TDM over Packet), ITU-T Y.1453: TDM-IP
interworking-User plane interworking, RFC 4553: Structure-Agnostic
Time Division Multiplexing (TDM) over Packet (SAToP), MEF18: Test
Suite for Circuit Emulation Services over Ethernet based on MEF 8:
Implementation Agreement for the Emulation of PDH Circuits over
Metro Ethernet Networks, RFC 4385: Pseudowire Emulation
Edge-to-Edge (PWE3) Control Word for Use over an MPLS PSN, ANSI
T1.403: Network and Customer Installation Interfaces--DS1
Electrical Interface, ANIS T1.231.02-2003(R2007): DS1--Layer 1
In-Service Digital Transmission Performance Monitoring, and REACT
test system.
[0064] With regard to protection switching, the MAD 700 is
configured to support IEEE 802.1ad Link Aggregation Control
Protocol (LACP), IEEE 802.1AX (prior 802.3ad) Standard for Local
and metropolitan area networks--Link Aggregation, Static Link
Aggregation support for legacy network applications, ITU-T
G.8031/Y.1342: Ethernet linear protection switching, G.8032/Y.1344:
Ethernet ring protection switching, Protection switching under 50
ms, and 1+1, 1:1, 1:N and Provider Backbone Ethernet Virtual
Connection (PB-EVC) E-line protection.
[0065] With regard to management, the MAD 700 supports IEEE
802.1AB: Station and Media Access Control Connectivity Discovery
(Link Layer Discovery), IEEE 802.1ag: Connectivity Fault
Management/Flow OAM, IEEE 802.3ah: Ethernet in the First Mile/Link
OAM: monitoring, signaling, loopback, ITU-T Y.1731 OAM functions
and mechanisms for Ethernet based networks ETH-APS (Ethernet
Automatic Protection Switching), ITU-T Y.1731 OAM functions and
mechanisms for Ethernet based networks ETH-RAPS (Ethernet Ring
Automatic Protection Switching), ITU-T Y.1731 OAM functions and
mechanisms for Ethernet based networks ETH-DM (Ethernet frame delay
and frame delay variation measurement), SNMP v1/2/3, Command Line
Interface (CLI), Telnet, and TIA 1057 Link Layer Discovery Protocol
for Media Endpoint Devices (LLDP-MED).
[0066] FIG. 9 depicts the card 10 edge connector 66 to a backplane
(e.g., of a shelf or other mounting device or enclosure 40, 42).
The edge connector 66 has DC contact closures (e.g., for legacy
applications) to provide information to the card 10 and therefore
user (e.g., via the LEDs) on the operation of DC contact closure
alarms. For example, dry contacts at pins 47 and 41 (e.g., R1 and
T1) are for a Link Down function on an enabled Ethernet port, LOF
or LOS on an enabled T1, or Unit failure. Power supply connections
indicated generally at 70 can be, for example, negative and
positive supply inputs (e.g., at pins 35 and 17, respectively) and
ground (e.g., chassis ground at pins 27 and 1). Dry contacts for
Far End Fault Indication (FEFI) are also provided as indicated at
72 (e.g., at pins 13 and 7 for R and T). The pins 72 on the edge
connector 66 provide FEFI or OAM Link down indicator on an enabled
Ethernet port, and AIS or RAI on an enabled T1. Simultaneous T/R
and T1/R1 contact closures indicate internal unit failure or loss
of power. As stated above, the LEDs 14, 16 and 18 can show
Ethernet, DS1 and UNIT status.
[0067] As described in connection with FIG. 1, the MAD 700 (e.g.,
card 10) is provided with a craft port (e.g., CRAFT port 20 which
can be a RS232 DB9 craft port) and a management port (e.g., an RJ45
Ethernet Out of Band (OOB) Ethernet management or MGMT port 36).
The CRAFT port 20 provides access for DS1 provisioning. For
example, the Craft port 20 can provide access to a menu-driven DS1
Command Line Interface (CLI) for provisioning of DS1 parameters.
The Craft port 20 can be accessed from a personal computer (PC),
laptop, or other computing device using VT-100 emulation (e.g., a
computing device running HyperTerminal or compatible VT-100
terminal emulation program connected to the CRAFT port 20 via an
RS-232 standard communications cable). Although the CRAFT port 20
provides access to a full range of provisioning and monitoring
capabilities associated with DS1 Structure-Agnostic Time Division
Multiplexing (TDM) over Packet (SAToP), also called DS1 pseudowire,
it is to be understood that most applications can be supported with
default parameters for the MAD 700. The following table provides
examples of default parameters for a MAD 700 in accordance with an
illustrative embodiment of the present invention.
[0068] Multiservice Access Device (MAD) Provisioning
TABLE-US-00001 Feature Option and Description Default A. Unit
Provisioning Unit State In service or out of service In Service
Unit Type Remote or CO: Remote is generally used Remote when the
MAD is at the subscriber site. CO is used when the MAD is located
on the central office side of the circuit, even though the MAD may
be physically installed in an RT cabinet and connected via fiber to
a downstream MAD Series unit at a subscriber site. B. DS1
Provisioning Name Permits assigning a 12-character name to DS1
#(1-12) each DS1 State Disable, enable (in service) or maintenance
Disabled (out of service) Framing Format Superframe (SF), extended
superframe ESF (ESF), or unframed Line Coding Bipolar with 8-zero
substitution (B8ZS) or B8ZS alternate mark inversion (AMI) Line
Build Out 0-133 ft., 134-266 ft., 267-399 ft., 400-533 ft., 0 to
133 feet 534-655 ft. DS1 Loopback Enable or disable Enable* DS1
Loopback 1, 2, 4, 8, 60 minutes, or No TimeOut 60 minutes* Timeout
Response to DS1 Send AIS to network (i.e., toward the CO Send AIS
(or Loss of Signal when the MAD is at the subscriber site) or
AIS-CI) to initiate loopback network NOTE: When AIS-CI is enabled
and the MAD is provisioned as an RT unit, an AIS-CI will be sent
toward the CO for a subscriber DS1 LOS. Loopdown on AIS Yes or no
No* AIS-CI Generation Enable or disable Enable* RAI-CI Generation
Enable or disable Enable* NPRM Generation Enable or disable Enable*
SPRM Generation Enable or disable Enable* ature functions only when
units are provisioned as Remote; feature is not applicable to units
provisioned as CO. Note: Changes to global DS1 settings can affect
enabled circuits. indicates data missing or illegible when
filed
[0069] Provisioning can be accomplished using a DS1 Interface
Configuration menu as indicated in the following table, for
example.
[0070] DS1 Interface Configuration (per DS1)
TABLE-US-00002 Parameter Default Configurable Values Line Build Out
0-133 ft 0-133, 134-266, 267-399, 400-533, 534-655 Ft T1 Loopback
Enable Enable/Disable T1 Loopback 60 Min 1, 2, 4, 8, 60 Min or
Never Timeout Response to Send AIS to Network Send AIS/Loopback T1
LOS toward network Loop down on AIS No No/Yes AIS-CI Generation
Enable Enable/Disable RAI-CI Generation Enable Enable/Disable NPRM
Generation Enable Enable/Disable SPRM Generation Enable
Enable/Disable
[0071] DS1 performance parameters can be accumulated and stored
over 15-minute and 1-day periods on a memory of the MAD 700 or
other local or remote memory. Parameter history is available at
15-minute periods for the last 96 intervals and at 1-day periods
for the last 7 days via the Performance Manager Menu. Current
performance monitoring (PM) data can be reset, and PM history can
be erased.
[0072] The Management Port (e.g., MGMT port 36 on the faceplate 12)
provides access to a Graphical User Interface (GUI) and permits
provisioning of Ethernet parameters, among other parameters such
as: System configuration parameters, Port configuration parameters
upon viewing link status, Security parameters, Network parameters,
Aggregation parameters (e.g., static parameters such as Hash code
contributors and group assignments, and LACP settings per port),
Link OAM parameters (e.g., Port settings such as OAM
Enable/disable, OAM Mode Passive/Active, Loopback Support
Enable/disable, Link Monitor Support Enable/disable, MIB Retrieval
Support Enable/disable, Loopback Operation Enable/disable, and
Event settings such as (per port) window and period threshold for
Error Frame Event, Event Seconds Summary, Symbol Period Error
Event, and Frame Period Error Event), LLDP parameters, Synch E
parameters, Alarm parameters (e.g., Ethernet Ring Protection
Switching (ERPS) settings, MAC settings, VLAN settings, QoS
settings), and Monitoring parameters).
[0073] FIG. 10 illustrates DS1 remote loopbacks implemented at a
site 42 using a MAD 700 (e.g., card 10) constructed in accordance
with an illustrative embodiment of the present invention. The MAD
700 in the mounting device at site 42 can recognize in-band and ESF
data link loopback codes.
[0074] To respond to DS1 loopbacks, the MAD 700 (e.g., card 10) is
provisioned as a Remote (CPE-side) unit (default), has its
loopbacks enabled (default), and is provisioned for either ESF
(default) or SF operation. When provisioned for ESF operation, the
MAD 700 will respond to either in-band or ESF data link
(out-of-band) loopback codes; when provisioned for SF operation,
the multiservice access device will only respond to in-band
loopback codes.
[0075] During a loopback, an alarm indication signal is sent to the
DS1 Tip1/Ring1 (receive) pair. If the multiservice access device is
provisioned for "Loopdown on AIS=YES" and the multiservice access
device receives (from the network link) an AIS signal in the DS1
circuit being looped back, the MAD loopback will be
deactivated.
[0076] If provisioned as a CO-side unit, the MAD automatically
disables all remote loopback detection. Loopbacks can be enabled on
any or all DS1s in a unit provisioned as Remote via a CRAFT port
loopback enable screen. Manual loopbacks are available on both the
CO and Remote units via the DS1 configuration screens.
[0077] Three types of T1 manual loopback are available for use via
the CRAFT port 20. These loopbacks can be accessed via the
Maintenance Manager Menu: (1) Network (toward network interface);
(2) Customer (toward DS1 drop interface); and (3) Bilateral (toward
network and DS1 drop interfaces).
[0078] The following table provides illustrative loopback
requests.
TABLE-US-00003 A. SF Configuration In-Band Loopback Code Binary
Activate (Network) 11000 (2 in 5) Deactivate (Network) 11100 (3 in
5) AIS (Deactivate)* All Ones B. ESF Configuration Binary In-Band
Loopback Code Activate (Network) 11000 (2 in 5) Deactivate
(Network) 11100 (3 in 5) AIS (Deactivate)* All Ones ESF Data Link
Loopback Code Activate (Line) 00001110 11111111 Deactivate (Line)
00111000 11111111 Universal Deactivate 00100100 11111111 AIS
(Deactivate)* All Ones *When unit is provisioned for "Loopdown on
AIS = YES"
[0079] As described above, the MAD 700 has a reduced form factor
(e.g., convenient plug-in card or module for use in many existing
T1 NIU shelves or other cell site and business telecommunications
equipment mountings) that can provide the desired integrated
diagnostics. Although the multiservice access device or MAD 700 is
miniaturized (e.g., as a card 10) so that it can fit on the
referenced standard mechanics of telcos, other similar versions of
the multiservice access device can be optimized for use in
relatively small outdoor boxes for deployment on exterior
telco-customer building walls in accordance with different
illustrative embodiments of the present invention. For example, the
MAD 700 can be deployed in a Network Interface Device (NID)
comprising a small enclosure having a separate, lockable interior
space for electronics, and an accessible extension with DS1 RJ48C
jacks, to provide a demarcation point between a carrier's local
loop and customer premises wiring. Regardless of the form factor,
the multiservice access device 700 can be purpose-built for Harsh
Environments (e.g., GR-3108-CORE Class 3 including 40.degree. C. to
+70.degree. C. operation) in accordance with an illustrative
embodiment of the present invention.
[0080] FIGS. 12A, 13A and 14 provide additional examples of a MAD
700 in accordance with illustrative embodiments of the present
invention. With reference to FIGS. 12A and 12B, a MAD 700
configured as a card, enclosure or other form factor device 76 can
map, for example, as many as 84 pseudowire DS1s (e.g., from cards
10) into an OC3 (e.g., connected to an ADM SONET). With reference
to FIGS. 13A and 13B, a MAD 700 configured as a card, enclosure or
other form factor device 78 can provide similar Ethernet
capabilities as described above in connection with the card 10, for
example, but without DS1s to address shifting a network to
Ethernet. For example, the device 78 can address 20,000 O3D3 TDM
units available from Pulse Communications Inc. A DS3 port 80 is
provided in lieu of a DS1 connector 34. While only 1 DS3 is shown,
additional DS3s can be accommodated in place of one or more
Ethernet drops 26, 28, 30 and 32. The MAD 700 shown in FIG. 14 is a
card, enclosure or other form factor device 82 having no DS1 or DS3
ports, and operates as a somewhat depopulated MAD 700 in the sense
that it provides Ethernet access while eliminating DS1 pseudowire
(PWE) costs.
[0081] As stated above and in accordance with illustrative
embodiments of the present invention, the MAD 700 comprises at
least two 2.5 Gb/1 Gb Ports (e.g., single fiber, dual fiber and/or
CWDM). The MAD 700 can also have at least four full rate GigE
subscriber ports (e.g., two SFP GigE and two RJ45 10/100/1000BT
ports, all with Jumbo Frame support and wirespeed switching core).
The MAD 700 provides complementary RJ48C demarc, connectorized and
stub ended DS1 cable options. The MAD 700 operates in accordance
with a plug-and-play universal mode with 1-to-1 Ethernet and DS1
port mapping end-to-end. The MAD 700 implements at least twelve,
integral, full featured T1 NIUs (e.g., inband loopback,
GR-1089-CORE 3a/b and 5a/b lightning protection, NPRM, SPRM,
AIS/AIS-CI and RAI/RAI-CI). The MAD 700 has an Ethernet processor
or other circuit or module with SynchE, IEEE 1588 synchronization
built in, as well as Stratum 3 and incoming DS1/DS3 synchronization
capabilities. The MAD 700 provides 50 ms Protection Switching
(e.g., built in ITU G.8032 ERPS and IEEE 802.1AX link aggregation),
OAM (e.g., IEEE 802.1ab, 802.1ag, 802.3ah, ITU-T Y.1731), and is
configured to withstand harsh environments (e.g., complies with
GR-3108-CORE Class 3 including -40.degree. C. to +70.degree. C.
operation in existing or new CP528 OSP demarc enclosures). The MAD
700 can implement micro-ring and daisy-chain topologies (e.g., with
single fiber delivery of dozens of DS1 ports and dozens of GigE
ports) and therefore facilitate expansion and resiliency, simple
growth, and low first costs. The multiservice access device can be
powered via 24/48 Vdc, as well as having remote powering and local
120 Vac powering capability.
[0082] In addition to comprehensive Layer 2 Ethernet and DS1
capabilities, the miniaturized or reduced form factor MAD 700 in
accordance with illustrative embodiments of the present invention
has unique installation capabilities to address the real-world
challenges faced when deploying Ethernet-over-fiber such as:
cabinets, relay racks, power, demarc relocation, fiber starvation,
resiliency; growth, turn-up time, existing infrastructure,
troubleshooting, training, DS1 transitions, site preparation,
planning, engineering, harsh environments, lightning, and
temperature extremes.
[0083] Thus, in terms of impact, it takes only about 30 seconds to
plug an MAD 700 (e.g., the simple all-in-one Ethernet and DS1
access card 10 shown in FIG. 1) constructed in accordance with an
illustrative embodiment of the present invention into many existing
T1 NIU shelves, either side-by-side or instead of existing
copper-based T1/HDSL plug-ins or other cards (e.g., O3-4D1, O3-12D1
or O3D3 units available from Pulse Communications Inc.). Expansion
is just as fast. The side-by-side card 10 is plug compatible with
other 400-mechanics TDM, Ethernet-over-SONET and Native-Ethernet
plug-ins (e.g., available from Pulse Communications Inc.) to meet
virtually any combination of legacy and emerging service needs,
even Program Channel High Fidelity Broadcast Audio links.
[0084] Illustrative embodiments of the present invention have been
described with reference to a card or other form factor with FPGA,
circuit board or other module programmable or configured to provide
at least the functions described herein. It is to be understood,
however, that the present invention can also be arranged in other
configurations construed as within the scope of the invention by
those persons skilled in the art to which the present invention
pertains.
[0085] While the invention herein disclosed has been described by
means of specific embodiments and applications thereof, numerous
modifications and variations can be made thereto by those skilled
in the art without departing from the scope of the invention.
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