Protection Switching Criteria For Tsncp; Table 7-13: Fault Criteria For Setting Tsncp Sf Flags - Ericsson Marconi OMS 1200 Product Description

7.6.3

Protection Switching Criteria for TSNCP

In general, the TSNCP switching criteria follows the same principles as defined in
Section 7.5.3 above, for VC-trail SNCP. However, additional fault types act as criteria
for setting the internal SF/SD signalling flag for autonomous protection switching.
There is also a different bi-directional APS switching protocol, which renders different
remote switching requests from the SMA at the far end of a protected tandem VC-trail.
The protection switching criteria for TSNCP are set out below.
7.6.3.1 Locally Detected SF/SD Flag Failure Requests
These switching requests arise from local detection of VC-trail fault types which act as
criteria for setting the internal SF/SD signalling flags for autonomous protection
switching. In the case of TSNCP, new fault types are added to the lists, from
monitoring over the tandem sub-layer VC-trails.
The SF flags are generated by outputs from the RST/MST/MSA/HPA/HPT functions,
the tandem VC-TCT/TCM functions, and the VC-POM functions. These functions all
reside on the bearer SDH interface units. The TCT/TCM functions are autonomously
enabled when you configure a protected tandem VC-SNC.
Depending on the network applications of TSNCP, these new fault types can either
add to the list of fault types, or provide alternatives to the lists. The complete fault type
listings are covered in Table 7-13 and Table 7-14 below.

Table 7-13: Fault Criteria for Setting TSNCP SF Flags

Fault Type
STM-n Loss of Signal
(RS-LOS)
STM-n Loss of Frame Alignment
(RS-LOF)
Multiplex Section AIS
(MS-AIS)
Multiplex Section Excessive BER
(MS-EXC)
Rx AU Loss of Pointer
(HP-LOP)
AU- Path AIS
(HP-AIS)
Loss of TU Multiframe
(HP-LOM)
TU Loss of Pointer
(LP-LOP)
TU- Path AIS
(LP-AIS)
HO Path Excessive BER
(HP-EXC)
HO Path Signal Label Mismatch
221 02-ZAP 701 25/1 Rev C 2006-08-04
03PHB00004AAV-CUA
Protection Enable/
Class Disable
SNC/I
SNC/I
SNC/I
SNC/I YES
SNC/I
SNC/I
SNC/I
SNC/I
SNC/I
SNC/N YES
SNC/N YES
© Ericsson AB 2006
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Marconi OMS 1200
Technical Product Description
Application Notes
All VC layer SNCPs
All VC layer SNCPs
All VC layer SNCPs
All VC layer SNCPs
All VC layer SNCPs
All VC layer SNCPs
only VC-1/2 layer SNCP
only LO VC layer SNCP
only LO VC layer SNCP
only HO VC-4 layer SNCP
only HO VC-4 layer SNCP
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