Alcatel-Lucent 1643 AMS User's Operation Manual page 559

Traffic maintenance
Termination points (TPs)
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Introduction
In the termination points the path overhead of the STM-1, VC-4, VC-3or VC-12 signal
is terminated (added or removed). In the AU-4, TU-3 and TU-12 termination points the
path overhead is not terminated, but can be monitored.
The following information can be retrieved from the path overhead:
• a Trail Trace Identifier (TTI), used for path trace
• a Signal Label, indicating what type of signal is carried
• error checking information, a signal degraded threshold can be set
Alarms
When a termination point is set to Monitored alarms related to this termination point
are reported. A termination point is set to Not Monitored (alarms are not reported)
when it is not used.
Path trace
To check whether a path is correctly provisioned a path trace can be set. A label (for
example a word) is sent along the path from one termination point to the other. This
label is called Trace Identifier (TI). If the TI is a specific string, this string is called
Access Point Identifier (API). If the expected API equals the accepted API, the
transmission path is well provisioned.
In the path overhead of a VC-4/VC-3 signal, byte J1 in the regenerator section is used
to the TI. For a VC-12 signal, byte J2 is used. A 16 byte frame is formed of which one
byte is used for error detection. Therefore the string that can be inserted in these bytes
has a maximum length of 15 characters (or 30 hexadecimal digits).
TIM detection
If the Trace Identifier Mismatch (TIM) detection is enabled, traffic will be lost when a
mistake in the trace string is detected. Upon mismatch, an Alarm Indication Signal
(AIS) is inserted in the downstream signal and a Remote Defect Indicator (RDI) is
inserted in the upstream signal.
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365-312-807R7.2
Issue 4, May 2007
Alcatel-Lucent - Proprietary
See notice on first page
9-7