sundance-communications.com/forum Forums TDM Business Telephone Systems Inter-Tel Telephones & Systems Soft switches and echo

Our CLEC uses a soft switch that converts the IP to a PRI using an Adtran unit. While using the the echo profiles has greatly improved our problems with echo, we still have a few daily incoming calls with echo. Some of the calls are cell calls and some from the wireline carriers.

Are calls with echo more a product of an IP PBX or our CLEC's soft switch or both. I'm trying to learn and resolve the echo issues (if possible)and not turn this into a finger pointing thing. What have been your experiences with echo?

I don't believe the LAN is an issue. Tests of the LAN show no dropped packets with very low delay.

The switch is a CS5000 with 2.3.6 sw.

Any ideas?

Echo is caused by a combination of two things: Reflection and Delay. Reflection is sometimes referred to as side tone or talkback, but basically it is the fact that you can hear yourself through the handset when you speak. This is induced by the fact that a handset is actually a 4 wire circuit (transmit and receive) that is converted to a 2 wire circut (in the case of a 2500 series set via Tip and Ring). This is known as a Hybrid. Reflection is normal and expected as that is the way a telephone has always sounded to the ear. You take away the reflection and users will complain. If delay is induced, the reflection becomes echo. Typically anytime there is a hybrid in the mix and you have delay, echo is the result. When I say 4 wire, that isnt literal, it really means a separate path for transmit and receive.
Analog DT- 2 wire
PRI- 4 wire
Analog Set- 2 wire
T1- 4 wire
ENet- 4 wire
you get the idea. It sounds as if you have all 4 wire circuits in your configuration, determining the source of the echo is going to be tough though it sounds like the echo is coming from the Telco; though it will be hard to prove. What is their stance?

Just found this thread. We sometimes have very bad echo and delay. Sometimes minor. We get it only on outbound calls and only the caller can hear it, not the other party. I had to mediate between our carrier and Inter-tel for months, each blaming the other. It seemed to go away for a while, but it's started to come up again. I haven't reported it yet, as I know it's just going to start the finger pointing again.

Our Telco denies any problem that causes echo. But they are a small company that has always bee honest with me. No reason to doubt their word. How rare is that? Moving all of the trunks to the highest echo profile helped a great deal, users reported.

BUT, we had trouble with one way transmission, in addition to the echo. We're not positive, but a lot of our issues may have been attributed to the T1 cards that our PRI's terminate on. Our vendor said that Inter-Tel had a problem with the T-1 cards that needed a software patch. Apparently, our switches' software level (2.3.6.47) didn't have the patch. They replaced the T1 cards with the dual models, updated to 2.4.1.39, and our one-way transmission ceased. Users report very few echo issues. But calling users and asking them if they have echo problems isn't someting I do a lot LOL. I'm busy enough!

I know our vendor spent a lot of time with Intertel to help them pinpoint the problems.

Hpe this helps.