PRI circuit - Screech upon call answer at attendant

[nord860]

Oue complany recently upgraded about 20 of our CO and TIE trunks accross the country to PRI and three different locations hear a loud screech before the call is answered by the attendant. In the event log, the only thing that shows close to the time of the problem is "Answer back merge failure" error code 1504. Avaya has no idea why this is happening. My thought is that it has something to do with protocol, but I'm not sure why all calls connect, and only some arrive with a screech. We turned off auto-answer at the attnedant and the screech stopped, however we can't keep it that way.

Thank you for your attention to this - looking forward to any suggestions.

 

[josiecza]

I would start by reviewing my DS1 config, Signaling Group config, and Trunk Group config. If that all looks good, you may want to check with your provider and verify the signaling with them, there could be a mismatch. I have had instances where my trunk group was set to FAS and the TelCo had their signaling set to NFAS. Very similar but different protocols.

 

[nord860]

Thanks for the feedback - That's where we'll start.