atcomsystems.ca/forum Forums TDM Business Telephone Systems Avaya - Lucent Telephones & Systems Poor voice quality Legend PRI

Customer has a Legend that we recently converted from 16 copper lines to a PRI with DID's. The initial cutover problems we had were typical scheduling BS between Verizon and the CLEC except now they are complaining about poor sound quality primarily when they call into their home office. Other party describes a "tunnel" sound to the call quality. CLEC has changed some settings on their switch, but did not fix the poor call quality. I don't want to change The DS1 card or start to assume it's in the Legend at this point. Any suggestions? Its a R7 Legend. The CLEC installed a Adtran unit which we ran directly into the T-1/PRI card in the Legend. DID calls route fine and we also have 2 copper lines (old hunt group pilot numbers) we forward after hours to an outside answering service and forward to the console DID during the day. All works well except for the call quality. Any quick thoughts? Thanks

Here we go again. The CLEC is likely using VoIP somewhere along the way and needs to revisit several paramaters. Push them 'til they get it right or move on to a different carrier. You can replace that T1 card if you wish, but I have far, far more confidence in Avaya's old iron than I do shiny new CLECs.

The tunnel or flange sound is caused by VoIP packets transmissions at a razor's edge of acceptable delay. Futher delays would cause full-fleged echo.

And don't let anyone tell you that you can't control the volume on a digital circuit. "What, you want us to make the zeros and ones bigger?" Whether you're working with true GR-303 or a softswitch, there SHOULD be a way to control the audio levels.

Ask the tech to look at "padding" parameters...perhaps even borrowing values from a known-working circuit. This may have to be done at the Adtran as well as whatever beast they have upstream.

Thanks Dwood. I thought I was the bad guy here, but everything works well except for that damn tunnel sound. I've forwarded this post to the consultant on the job.Thanks again.
Rich

Dwood, you were correct. I got the carrier to change the PRI to connect directly to their DMS switch. We got rid of their adtran and put in our own adtran csu and the problems went away. Thanks for your help.

Thanks, bro. But it sounds like YOU were the one who did all the work. All I did was point out the obvious.

In any case, I'm glad that it worked out and that you found this board. Keep coming back.