Intermittant echo on lines

[busster]

Customer using IP500v2 in basic mode. 4 pots lines. 9508 phones. Plantronics c054 headsets. Complaining of echo on calls. Verified and re-grounded the system. Checked voltage on the lines, all four between 46 and 49 volts on the meter. When on a headset call they sometimes hear echo. While on the same call, if they move to the handset, no echo. If they move to the speaker, it may or may not give them terrible feedback screeching and echo.
Turned off the speaker AGC. This helped with the speakerphone screeching and feedback sounds, but did not completely resolve the echo problem.
Called Plantronics and verified their recommended settings on the headsets working with 9508 phones. Changed headset settings within the 9508 phones to see if it made a difference.

Swapped around ports, headsets, and physical phones. No change.

Can not narrow down the echoing to specific telephone lines, headsets, or 9508 phones.

 

[kelltele]

Do you hear the echo on a buttset? if so check loop current should be 20ma to 35ma.

 

[busster]

No echo on lines directly on the DMarc

 

[TouchToneTommy]

I had a site with 1416's and CS540 headsets. Lots of echo on headsets only. Fine at demarc, settings on headsets correct for phone type. Fix was a factory reset of the headset

1) Place the headset in the base station.
2) Then unplug the power supply cable from the base station.
3) Remove the headset from the base station. Turn off the headset by pressing and holding the talk button (the 4 LED lights on headset will flash rapidly red, then stop).
4) Place the headset back in the base station
5) Plug the power supply cable back into the base station (Headset will automatically turn back on).