Description
After many complains about several services got suddenly stopped, it discovered that the services pass-through a specific NE which is Huawei OSN1800 works as POTN.
When browsing the PWs which carry the services, there were no alarms on them, but when checking the real time performance, we found the traffic was totally stopped.
real time performance for PWs is 000
Procedures of Check
First I checked the path of all PWs, they all had one thing in common, they pass through a specific tunnel. The Tunnel path was correct and no fiber cut or fault along the tunnel path also the tunnel has 1:1 tunnel protection.
But there were a minor alarms “Ethernet APS switch fail” also “Eth APS lost” , the alarms indicate that protection of ethernet is lost or stopped.
Ethernet APS problem
The Solution
First, checking the protection group of the tunnel and the group members and state. The group was created correctly and deployed, also the traffic was on the working tunnel not switched to the protection.
Tunnel protection group
After checking historical alarms, it is found that the source NE of the tunnel had quick power off before alarm appearing that mostly is the reason of the alarm. The NE has probably hanged up while trying to switch tunnels from main to the protection.
Note:- if the Main Tunnel in the protection group is normal (not in fault state), so you can undeploy or even delete the protection group with out any affect for the services, because protection group is just to bind Tunnels in 1:1 relation.
After un-deploy and deploy the protection group the alarm persisted, so I deleted the protection group and then recreated it again using same tunnels, after that the alarm disappeared and the traffic flowed in the VPNs inside tunnels normally.
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