Story 1 Details:

One day I have got call from our supervision team that MSC connected to one pair NE40E router is getting total service outage. Then I have logged into our NE40E_X8 routers and found uplink between A (PE) router and P router is down due to fiber link down. The link between router B (PE) to P was up. So the traffic should go router A (PE) --> router B (PE) --> P router (as this MSC voice and Signal traffic connected as active/standby VRRP mode, So all traffic coming from MSC to router A (PE) as this is VRRP master).

Then I have tried to find out the problem. Found OSPF peer between router A (PE) --> router B (PE) and router B (PE) --> P was up. So, no problem is in dynamic routing. Traceroute and PING was successful from both router to other routers that was located in different MSC. That time I was getting confused. What is the problem?

After that I have checked the MPLS and MPLS LDP between router B (PE) --> P, that was ok. Then I have found MPLS LDP session was down between router A --> router B. I found that mpls ldp configuration was missing router B.

I have configured that command in router B. Then all the traffic of that MSC was up and everything was ok.

Thanks//

very good & keep it up...