feedback on SIP phones

[RLyon]

I have a client whos Sip Phones with analog lines have been working great. They were with a standard ISP but switched to fiber and now they are getting feedback on their phones. What could be the issue?

[Tech Electronics]

RLyon,

Most likely this is an issue with the Fiber to Analog conversion process that is not balanced out correctly by the provider.

Hook a test set on the analog [POTS] connection and see if the problem is there as well. If the problem doesn't exist there then rebalance out the MiVO-250 with the new analog [POTS] lines.

Depending on how long you have been in this line of work you may have run into a Hybrid-Balance issue and this is one of the issues you can have.

Thanks,

TE

[RLyon]

The Hybrid Balance refers to the Echo on Analog Loop Start Trunks. While I do have Analog Loop Start Trunks, I should clarify that the feedback is a static noise on outgoing calls. I believe the caller hears the static, but the receiver does not. I should point out that they are using 6900 SIP phones. I know 6900's are not ideal for the Mitel 250 system, but that is what they wanted. I know there is the feature code 320 for Audio Diagnostic and it leads you through a prompt where you can choose static. I am trying to figure it out with out interrupting the client.

[RLyon]

We had the client put in a Loop Current Attenuator e.g. Independent Technologies ITC-4001