Symptom
An OptiX OSN 6800 NE contains two subracks. The master subrack houses an active SCC and a standby SCC. The software package on the active SCC is correct and complete. A new OTU board is inserted, whose software version is different from the software version of the SCC. The NE software cannot match the software package automatically.
The SWDL_CHGMNG_NOMATCH alarm is reported. In this process, no SCC in the master subrack is removed, inserted, switched, or replaced.
Cause analysis
The SWDL_CHGMNG_NOMATCH alarm means SCC board changed alarm. The system re-checks whether the board software of each board matches the NE software after the NE starts up upon a power failure, the SCC unit is replaced, or a cold reset is performed on the SCC unit. The alarm occurs when the board software of a board mismatches the NE software. It indicates that the board software mismatches the NE software.
The software package is automatically matched in two stages:
In the startup process, the SCC only detects the board version, but does not start auto-match of the software package. After the SCC starts up, the SCC checks whether the board supports package loading. If yes, the SCC checks whether the software version of the board is consistent with the NE software version. This interaction process starts from the startup of the NE software and continues until the SCC changes from the pending stability state to the normal state.
The auto-match of the software package starts only after the NE state changes to normal. At this time, if no alarm related to package loading is reported (that is, the alarm that begins with SWDL_), the SCC matches the board software automatically. In the case of the board whose software version is different from that of the NE software, the SCC delivers the board software stored on the SCC, and activates the software.
If any alarm related to package loading is raised on the NE software, however, the SCC does not perform auto-match of software, but reports SWDL_CHGMNG_NOMATCH alarm.
NOTE:
The board here means any board except the active SCC of the master subrack, including the standby SCC of the master subrack and the SCC of the slave subrack.
Procedure
Use the correct software package to perform package loading successfully. If the SCC has a version identical with the software version of most boards (except one or two boards) in the software package, the loading process is quick, and the board with loaded software package is reset.
