Mitel 5000 6.1 Loop Start Hybrid test result meaning

[Crowtalks]

New Mitel 5000 6.1 with four Loop Start Trunks and five IP phones. Customer complaining of feedback/echo (customer had a AT&T/Lucent Partner system previous to this one).

I set the trunks to transmit of -12 dB which helped tremendously but they are still complaining somewhat of call quality (I don't hear it, but I have 60 year old ears). I ran a Hybrid Balance test and the result were:

Best Effective ERL for trunks one-thru three is 15.xx (...average was 15.35), but Best Effective ERL on line four is 3.xx.

What does Best Effective ERL mean?
What does the disparity between trunks 1-3 and trunk 4 mean?

[Tech Electronics]

Crowtalks,

Did you run a Loop Loss Test prior to doing the Hybrid Balance test?

Best Effective ERL means it is the best that the system could determine for the Echo Return Loss which is the amount of signal loss applied to the original far-end signal that returns as echo.

You have to take the numbers on an individual basis unless they are talking to one another. The bad part is that the first 3 trunks have terrible Echo Return Loss or your Hybrid Balance Circuit is out of phase with theirs. In an ideal world you would have an ERL of 0 on the Mitel 5000, but that will most likely never happen.

If you need to understand those terms better than you may want to go to www.sandman.com and learn more about them. There are physical circuits you can put in place to help alleviate it, but most likely calling the carrier is not going to help unless the circuit is outside their specifications.

Thanks,

TE