Netvanta 7100 and Polycom VVX 400 Phones have internal feedback

[braintoss]

Howdy!

I installed a system about 2 weeks ago, and ever since the customer has been having random feedback issues (they hear people in the same room as them echoing through the handset). I tested this today on site and found the issue happens even when the phone volume is lowered below the halfway point. I'm not sure where to go from here, I've tuned the lines (2 analog trunks) but it didn't help. If I can't figure out a good solution I'm going to try to swap out the unit with a demo unit I have sitting at the office. Any help is appreciated!!!

- Jason

[Anonymous]

Jason, what voice codec are the phones using? Thanks

Jay

[braintoss]

Thanks for your response! Sorry about my delay - alas, the issues still persist a bit - Not all the time but randomly.

They are using G.711 uLaw - I'm attaching a log - curious to why only one extension (202) is showing  as having higher delays. The other extensions always have 50/50 avg/max delay.

The LEC swapped the port at the CO - This seemed to clear up a bit of the line echo which I was getting directly from the NID.

I also enabled ANLP on the lines/extensions - which got rid of the dual voice white noise issue.

As I was about to leave their office yesterday, the customer states they heard an echo. Can't confirm this, going to follow up with the customer later today.

Thanks!!!

[Anonymous]

Jason, can you try swapping that phone out to a different port or wire run? There shouldn't be any internal network delays unless there are network issues.

[braintoss]

I'm on a different port and directly into the unit - no IW at all. Still getting an echo/static white noise. It's adjustable with the transmit/receive gain - but I can't get it to completely go away. =(

[braintoss]

Another update. Used a completely different 7100 connected to one of the analog lines and a completely different phone. The problem still occurs. It seems like it's on the Telco side, but they've been out and changed the wire to the building already. Is it maybe something to do with the way the 7100 is reacting to their switch in the CO?

We are planning a work around for this issue ... going to be installing some Voip lines to replace the analogs eventually. But I'm still curious as to why this is happening, and will it happen if I install another system in the same area, using the same CO possibly.

Thanks again!

[Anonymous]

Jason, have you run the ERL test tool on the line? Thanks

Jay

[braintoss]

Yes I ran the ERL tool a few times - sometimes it would just fail the line.

Anywho - update - We converted the lines over to VoIP - and the echo problem is gone. I don't know what it was, but Telco insists that their copper had nothing to do with the interference.

Either way - I'm gonna say this is closed - until it happens again maybe hah.

Thanks everyone for the help!

[Anonymous]

Jason, I went ahead and flagged this post as "Assumed Answered". If any of the responses on this thread assisted you, please mark them as Correct or Helpful as the case may be with the applicable buttons. This will make them visible and help other members of the community find solutions more easily. If you still need assistance, we would be more than happy to continue working with you on this - just let us know in a reply.

Thanks,

Jay