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IP 650 Local Echo Problem

Occasional Visitor

IP 650 Local Echo Problem

We have an issue with our IP 650 phones where the person using the phone hears an echo of their voice. Most of the time this only happens  in the first 10 to 15 seconds of the call but sometimes happens longer. Everything sounds fine on the other end.


The phones are using the UC 3.3.2 firmware and the server is running Elastix 2.


We were not able to hear the echo in call recordings initiated from elastix or even in wireshark captures which leads us to believe it is a phone issue. It has been reported in 4 out of our 20 phones but those 4 are the ones that use the phone the most.


Any insight into this issue would be appreciated.

Message 1 of 3
Polycom Employee & Community Manager

Re: IP 650 Local Echo Problem

Hello Noventech,


welcome to the Polycom Community.


Please follow the suggestions in the FAQ before posting a new Question to search the Feature Descriptions & Technical Notifications.


You could have found this Document => here <=


Please follow these troubleshooting Tips and ensure you are taking a Wireshark Trace at the mirrored/spanned Port of the Phone.


Other community Members may have additional suggestions for you.


You may, in addition, want to contact your Reseller or if the Phones are outside warranty to work with Polycom Support via PPI (Pay Per Incident) to get further assistance.


Best regards


Steffen Baier


Polycom Global Services

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Message 2 of 3
Occasional Visitor

Re: IP 650 Local Echo Problem

Thanks. I did find that article before but was unsure how to perform the procedure below. Can you clarify what I should set the gain to. It also references a pre UC settigns file, maybe this should be updated for the new UC 3firmware.


For handset issues:

— In the sip.cfg configuration file, reduce the value of voice.gain.tx.analog.handset by 6.

As of SIP 3.0, voice.gain.tx.analog.handset is set to 6


Also, I attempted to open a support ticket with Voip Supply but they've been incredibly unhelpful. The phones are brand new and we've been having these issues from the beginning. Can we open a support ticket directly with polycom?

Message 3 of 3