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Too much noise in inbound calls

We have an installation with CCM 3.3(3) and the connection to PSTN are two PRIs E1 in a 6608 card. The outbound calls are OK, but now and then the inbound calls are received with lot of noise and it is impossible to hear any word. If the call is repeated after a while (one minute) you don't have this problem. Which can be the cause of this noise?


Re: Too much noise in inbound calls

After receiving a noisy inbound call, you might try haivng the far end hang up and repeating the call, to see if the noise repeats. I don't really know, but you might try this to troubleshoot. Assuming your traffic load will permit: Put outbound calls on one PRI and inbound call and the second PRI. If you continue to see noise on inbounds, then reverse the PRI's to see if the noise follows. This will tell you whether or not you have a PRI span that is giving you random problems. The other approach would be to put all traffic on one PRI and open a trouble ticket with your carrier and have them test the span (make sure they test using more than one test pattern to stress test). If that tests clean move the traffic over to that span and have the carrier test the second span. The above will rule out PRI span issues. Another approach would be to record the details of one inbound call with noise and open a trouble ticket with the carrier and have them do some testing. You might also try moving to another port on the 6608 blade if you can isolate the noise to a specific PRI (assuming you have spare ports). Just some thoughts, anyway good luck.

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