Merge Manager; Trunk Unwrapping On The Per-Port Switching Modules; Trunk Unwrapping On The Module-Switching Modules - IBM Nways 8260 Manual

8.12.3 Merge Manager

The function of the Merge Manager is to periodically check RI and RO trunks to
see if the cause of the beacon has been resolved and the trunks can be
unwrapped.
To check the trunks, the Merge Manager creates a ring segment with the trunk
under the test and the URA.
The URA checks to see whether this ring segment either has an Active Monitor
(indicating a healthy ring) or is capable of passing traffic generated by the URA.
If the segment passes one of these tests, the trunk is deemed to be recovered
and is unwrapped. If it fails the test, retry will be attempted at intervals
described below.

8.12.4 Trunk Unwrapping on the Per-Port Switching Modules

For trunks attached to the 18-port active per-port switching module and the
10-port dual fiber repeater module, merging (unwrapping) is attempted:
Because these modules have switching capability, the Recovery ASIC may be
switched onto the faulty segment without disturbing the rest of the stations on
the module. Thus, we can test faulty segments without disrupting the working
ring segments.

8.12.5 Trunk Unwrapping on the Module-Switching Modules

For trunks attached to the module-switching modules merging (unwrapping) is
attempted:
1. Every 5 seconds
2. Every 30 seconds
3. After 5 minutes
4. After 20 minutes
5. Never again. This means that manual intervention (using D M M commands)
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8260 Multiprotocol Intelligent Switching Hub
Note
On the 18-port active module switching module, the URA cannot be switched
to the backup path. This means that the operation of this module is not IEEE
802.5C conformant.
Note
The Merge Manager algorithm is the same on the per-port switching modules
and module-switching modules; the only difference is in the timers which
determine how often the trunk test gets executed.
After 5 seconds
After 30 seconds
Every 5 minutes
will be necessary to unwrap RI and/or RO ports.