Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

slowly incrementing T1 errors

We have have a problem with a t1 circuit, the circuit is a point to point t1 line with clocking set to line, every few weeks the crc's start incrementing at a wild rate, and we have to reset everything inorder for it to come back. the Question I have if there is a problem with clocking would it take a few weeks to show itself like that or what do you think might be causing this? Also during the time when the circuit is fine the Crc's never increment.

New Member

Re: slowly incrementing T1 errors

Have you taken loop tests with your Service Provider at both ends.Try to isolate it at both ends. Incase the errors occur at a particular time of the day repeatedly you need to talk to your provider.

VIP Purple

Re: slowly incrementing T1 errors

Hello Dave,

since you say the problem occurs only once every few weeks, you might want to check with your provider to see if they can see those errors as well and if they might be caused by something on their side. If these errors were due to a faulty cable or a noisy serial line, they would most likely appear more often.

There is a pretty comprehensive document which explains some testing mthods to isolate the cause of these errors, not sure if you have already seen it:

Troubleshooting Serial Lines



New Member

Re: slowly incrementing T1 errors

thanks both u guys, I'm going to talk to the provider

New Member

Re: slowly incrementing T1 errors

I would also check with the provider to ensure they are providing clock for the circuit. We've had cases where providers didn't provide clocking on the circuit so we had to configure our CSU (or internal on the router) to provide timing on the circuit in some cases.

CreatePlease login to create content