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Multiple E1 in one router problem


I have a 3660 router with 6 connected E1. (3 NM-2CE1U).

When E1, connected to controller 1/0 goes down (shutdown on remote end), I started to loose packets on E1, connected to controller 1/1.

All controllers are configured equally:

controller E1 1/0

framing NO-CRC4

channel-group 0 timeslots 1-24

"Show controller E1" shows that all controllers have "Clock Source is Line" and zero counts for all errors.

The IOS version is c3660-is-mz.121-5.T.bin

I think this is the problem related to clock synchronization but can someone advise?



Re: Multiple E1 in one router problem

Are you using any sort of load balancing? If not, check for bugs, and then give the TAC a call.

Community Member

Re: Multiple E1 in one router problem

I'm guessing that you have more than one telco? There are known issues when trying to recover network timing from multiple sources. I haven't actually ever had that problem myself, so I'm not sure if it is only a problem if you do it on the same multi-port interface or if it can be a problem on an overall chassis. There have been some threads in the past where I seem to recall that a TAC CCIE chimed in. Can't seem to find it in the archives though.

Also, of course, it could just be a misconfiguration. You can only recover timing if the other end is providing it or telco is timing via a DACS.

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