Sync
Status Message Software For Dallas/Maxim Devices
NComm
Sync Status Message Software provides a complete software solution
for the implementation of a T1/E1 system. It will be
complete and is designed to come up completely functional
with no additional work required to achieve full standard compliant
operation.
This
module will perform the SSM processing according to GR-253, ETSI
300-417-6-1 and G.781. Additionally, as with other NComm TMS modules,
the SSM software is completely data driven, allowing operating modes,
and thresholds to be configurable on a static or run time basis. The suite
includes 2 levels of ANSI-C Application Programming Interfaces (APIs),
encapsulating the details of SSM operation and the underlying hardware
elements, and providing a clean integration to the target system’s
operating environment.
Target
Applications
- Single and Multiple-span T1/E1
- T1/E1 and M13
multiplexers
- PBX and Channel Bank
- ISDN/PRI HDSL transport
- VoIP (Voice over IP)
- Router/GatewayProtection Switching
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Main
Features
- To maintain traceability to a identifiable primary clock
reference source
- To ensure that higher stratum clocks are never slaved
to lower stratum clocks
- To ensure that all Network Elements have both a primary
source and a secondary source in case of a primary failure
- To
ensure that timing loops are avoided
- Runs with or without Real Time Operating System (RTOS)
on virtually any processor and host environment. Currently
ported to Linux, OSE, VxWorks, and Nucleus
- Simple Application Programming
Interfaces (APIs)
- Processor independent ANSI-C
source code
- Fully customizable
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SSM Trunk Management Software (TMS) Architecture |
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In an environment of a hierarchical network, clock traceability
is fairly straight forward, and at least logically manageable
with respect to quality and source. In the flat landscape
of SONET/SDH networks, this could be much more difficult.
And, not only are these newer networks flat, they also will
tend to be owned by many different providers.
To address this potential weakness, SONET/SDH adds a new mechanism
to both make it clear of the quality and traceability of the
clock source, and to permit the network to intelligently choose
the best clock from those available should an issue arise.
This new mechanism is the Sync Status Message (SSM) and the
rules of use associated with them.
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The SSM Module will have the following features:
- Determination of the proper source from which to generate
timing by processing the TBs (see below for definition)
- Interface to a Timing Device Driver (i.e. DS3100 chip's
timing functions).
- The processing of timing input from external Line cards
(e.g. S1 byte-sonet/sdh, SSM/TM-e3, BOC-T1, Sa bits-E1)
[TERMINOLOGY NOTE: This is called Timing Bits (TB) from
now on]
- Provision for Redundant timing card control and switch
over between them for support of equipment redundancy requirements.
- Provision of transmit relay of timing control information
(i.e. updates Tbs) for the system in the transmit direction
- Algorithms for controlling timing per GR-253 for SONET/T1.
- Algorithms for controlling timing per ETSI 300-417-6-1
and G.781
- Algorithms will default to standard plus be selectable
and configurable by the user
- A well defined API consistent with current NComm TMS
products
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Telecom
Devices