Nortel Networks 8000 - Manual (Page 66)

Nortel Secure Router 8000 Series
Configuration -WAN Access 4 POS and CPOS interface configuration
The two TU-12s are adjacent if their numbers of TUG-3 and TUG-2 in the VC-4 are the same
while the numbers of TU-12 differ by 1.
CD
NOTE
The number in the preceding formula refers to the location number of VC4 frame.
The value of the number of TUG-3s ranges from 1 to 3; the value of TUG-2 is from 1 to 7 and the value
of TUG-12 is from 1 to 3.
The number of TU-12 indicates which one of the 63 TU-12s is in the VC-4 frame according to the
sequence.
Figure 4-4 Sequence of arrangement of TUG-3, TUG-2 and TU-12 in VC-4
When using the multiplexing route of AU-3, the calculation method of TU-12 sequence
number can be deduced accordingly.
When you configure the CPOS interface with 63 E1 channels or 84 T1 channels, you can
directly apply the channel using numbers ranging from 1 to 63 or from 1 to 84. If you use
channelized STM-1 interfaces on the routers from both Nortel and other companies, note the
difference in numbering.
Overhead bytes
The SDH monitors the section and channel layers.
Monitoring the section layer involving the following types of monitoring:
• Regenerator section monitoring
• Multiplex section monitoring
Monitoring the path layer involves the following types of monitoring:
• Higher order monitoring
• Lower order monitoring
Overhead bytes implement the monitoring functions.
Issue 5.3 (30 March 2009) Nortel Networks Inc. 4-5