Customer reported a services was interrupted after the 1+1 LMSP switching. TU-AIS alarm was reported on the interconnected MW equipment and OSN report LP-RDI alarm..
The OSN equipment is OSN3500 and the version is 18.104.22.168.
Two solutions for this issue:
1.Upgrade the software to V2R11C00SPC300(22.214.171.124) or later version.
2.Replace the SSN1PSXCS board with SSN2PSXCSA board.
1.Frist we check all the SNCP group on the equipment. We find the working SNCP PG-ID is from 1 to 58, at same time the protection SNCP PG-ID is from 1951 to 2007. Please check attachment.
2. For the N1PSXCS board, it can support a maximum of 1184 SNCP pairs in V2R11C00 version, and the PG ID range should be no more than 1184.
If PG ID is larger than 1184 when we check it on the GSCC board, it cant be dispatched to cross-connection board successfully.So it means that all the cross-connections for the PG-ID larger than 1184 are not configured on the N1PSXCS board.
3.The larger SNCP ID is used for the SNCP auto-created normally, such as protection SNCP on 1+1 LMSP.
So this is the reason that the services were interrupted after 1+1 LMSP swiching.
3.This issue is caused by a customer requirement. One customer wants to increase the maximum SNCP paris of N2PSXCSA (from 1184 to 2016.).But GSCC software added it to both N1PSXCS and N2PSXCSA boards by mistake.
To confirm the issue:
we can get the SNCP PG-ID from PSXCS board by optp command:
:optp:9,0,ad,1,23,03; //check all the SNCP PG on the 9-XCS board
Through comparing the result from GSCC and PSXCS board, we can know whether any SNCP is lost on the XCS side.
Optp cmd : 2303
00 03 07 df 00 02 00 01
Total records :1
It shows that total 3 SNCP PGs,PG-IDs are: 0x07df,0x0002,0x0001.
SSN2PSXCSA board can support a maximum of 2016 SNCP pairs in V2R11C00 version,but this is not mentioned in the product manual, and not suggest to tell all the customer.