Equipment Type: Metro 1000V3
NE Version: 5.37.02.22
T2000 Version: T2000V200R006C01
Customer reported that broad band services of one of their ONU is down and it was not connecting to DSL terminal. 8Mb (4*E1) Service is configured from ONU (Metro1000V3) EFS board till their ADM (Optix 2500+) EFS board. EPL service
is configured for transporting broadband service. Configuration detail is as,
Metro 1000V3: EFS board
Port1, VCTrunk1, VC4:2:22,23,24,25.
Optix 2500+: EFS board
Port2, VCTrunk11, VC4:2:22,23,24,25.
Following steps were performed to handle the issue.
1- Services were checked end to end but no issue found.
2- Checked the Ethernet service including VcTrunk bound E1’s at Metro 1000V3 and Optix 2500+, no issue found.
3- Check the trail for all four E1's they are using the same route from ONU to ADM.
4- Checked the link losses in the whole ring but no abnormality found.
5- Reconfigure the Ethernet service but this also didn’t resolve the issue.
6- Change the VCTrunk at Metro 1000V3 but VCAT_LOA alarm reappeared again.
7- Change the VCTrunk at Optix 2500+ but this didn’t resolve the issue.
8- Remove the last three 3E1’s (VC4:2:23,24,25) form both VCTrunk and configure the service at 2Mb (1*E1), this time VCAT_LOA alarm removed from Metro 1000V3 EFS card and ONU connected to DSL Terminal.
9- Include the second E1(VC4:2:23) in VCTrunk1 and then check VCAT_LOA alarm didn’t appear.
10- Include the third E1(VC4:2:24) in VCTrunk1 and then check VACT_LOA alarm reappeared again at EFS card and services went down again.
10- Eliminate the third E1(VC4:2:24) from VCTrunk1 and include the fourth E1(VC4:2:25) so the service configured at 6Mb (3*E1) and then check VCAT_LOA alarm removed and service is working fine. So the third E1 in link have some issue due to which VCAT_LOA alarm is appearing at EFS card and services are
not working fine.
Following are the possible causes.
1- Services wrongly configured.
2- Ethernet service not properly configured.
3-Service path have Bit errors.
4- Link losses in ring.
5- Timeslot configured in VCTrunk are using different path of different distance.
6- E1’s bounded in VCTrunk have some problem.
7-Problem in VCTrunk at Metro 1000V3 or at ADM (Optix 2500+).
While troubleshooting VCAT_LOA alarm do check if some E1’s have issue or not.