I have got a CISCO router on our end and Adtran router at the remote end. AT&T with the help of LEC is providing us T1 line. Lately the line has been going up and down and we suspect clock issue being the cause. We ave done some testing on both of our ends and confident that there is no hardware failure and cables are OK.
We have set the clock source as "line" both at CISCO and Adtran . For the past year or so there has been no problems with the line and everything was OK. Now that we have issues , we suspect problems with T1 line.
I understand that if AT&T is not providing clock for the T1 line , we would have to provide that clock on our router end.
So if AT&T is not providing clock, I would set
CISCO router : clock source "Internal"
ADTRAN router : clock source "line".
My question here is , Is there a way that I can determine from my end whether clock is being provided in the T1 line by AT&T.. I am sure asking AT&T over phone would be the easiest but I am curious to know If I can determine and If yes, How ?
If yes , should I being any device to do that..
Hope I am clear