[Problem Description]
Trigger conditions:
An NE is powered cycled, and the SS49EFS board is cold reset.
Fault symptoms:
An OptiX Metro 1000 NE is interconnected with a third-party SDH device using SS49EFS boards. The alarms such as LP_TIM_VC12 and LP_SLM_VC12 are reported on the SS49EFS boards on the OptiX Metro 1000 NE. Consequently, the services on the SS49EFS boards interconnected to the third-party SDH device are interrupted.
Identification method:
All of the following conditions must be met at the same time:
SS49EFS boards earlier than V3.05 are configured on the OptiX Metro 1000.
[Root Cause]
After the SS49EFS boards are cold reset, the NE delivers overheard configurations to the boards. If no VCTRUNK is bound on the channels, the NE will read the default J2 and V5 bytes from configuration files and deliver them to the SS49EFS boards. The NE first delivers VC-12 overheads and then VC-3 overheads. The first three channels on an SS49EFS board are shared by VC-12s and VC-3s. The VC-12 overhead configurations will be overwritten by the VC-3 overhead configurations
[Impact and Risks]
After an NE is powered off or the SS49EFS board is cold reset, the services on the equipment interconnected to third-party SDH equipment may be interrupted.
[Measures and Solutions]
Recovery measures:
Check the received bytes on the SS49EFS boards. Reconfigure the to-be-transmitted and to-be-received J2 and V5 bytes on the SS49EFS boards to ensure that the to-be-received J2 and V5 bytes are the same as the received J2 and V5 bytes. (The problem will reoccur after the cold reset or power-off.)
Workarounds:
Do not use the one to three timeslot when configuring VC-12 services on the SS49EFS boards on an OptiX Metro 1000.
Solution
The SS49EFS board V3.06 resolved this problem.
[Rectification Scope and Time Requirements]
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