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New Member

Troubleshooting Echo's on 6608 and 6624 Modules

Hi, I am just starting to troubleshoot a few reported Echo's at one of my VoIP sites. I am curious if anyone has had success with adjusting the "Audio Signal Adjustment into IP Network".

I have a 6608 module with three PRI to NI2 switch and a 6624 module with 24 ports to Brooktrout voice cards on an Avaya UM server. I am getting consistent echos when calling from the PSTN into the Avaya UM server for the first few seconds of talking, then the echo cancellation seems to adjust and remove the echo. I also have reported echos on calls originating from IP phone going out the PRI's.



New Member

Re: Troubleshooting Echo's on 6608 and 6624 Modules

We are having the exact same problem with the echo, I have tried adjusting the signal strength numerous of times but nothing has worked so far. Today we are having our local provider come out and test the lines to see how "hot" they are coming in. Once that is determined we will then have the local provider make some adjustments to the lines. I will get back with you when I get our results

New Member

Re: Troubleshooting Echo's on 6608 and 6624 Modules

Had the same exact problems. You have to tweak your db settings on the gateway config. We had to decrease our db settings to -6db in and out of the IPT network to get consistency. (no echo) We also upgraded our 6500's and the code on each 6608 port (through ccm).

New Member

Re: Troubleshooting Echo's on 6608 and 6624 Modules

Thanks for the replies. I will be upgraded CCM from 3.08 to 3.09 this Sunday, just to get the last code. I have CatOS 6.1(2) on my 6500's, which I will stay on for now. I'll open a problem ticket to get the PRI's tested. Then I'll start making adjustments on db settings. I'll post my results.

Cisco Employee

Re: Troubleshooting Echo's on 6608 and 6624 Modules

I don't think any amount of dB tuning will make a difference if the echo is only present for the first few seconds of a call and is then gone for the remainder of the call.

That is what is heard when the ECAN function of the DSP converges.

There is work underway for a more robust ECAN function in the DSPs across several platforms, but I can't give you the what/when/how etc. because I don't have more details. I would suggest you engage your account team for more info on this topic.

Please note that this problem does not frequently occur, mainly due to inter-lata and IXC echo cancellers being properly provisioned with long tail circuits to handle round-trip delays encountered over long circuit distances. However, it's obviously not always that way.

Email me if you need more info.