[Asterisk-Users] Re: Echo and other reasons to migrate to BRI from POTS? Was (Echo on PRI/BRI?)

[Brent Torrenga]

Paul,

Ah, I see. Our echo is largly under control now. It took me a while to
figure out the gains and get them tuned, and now the echo only leaves very
small artifacts. Nonetheless, this still provokes the odd complaint here and
there. We use VOIP for outgoing calls when our POTS lines are congested, and
we find zero echo during those calls. Therefore, I assume that our handsets
(Cisco _79[46]0's) handle echo properly, and the source is our local loop.

I suppose then I cannot promise that migrating to a pair of BRI circuits (4
channels) will eliminate echo. It would be safe to say that echo would
PROBABLY be eliminated?

Other reasons to migrate: eliminate static/line noise (from our local loop,
can't do anything about the other end), speed up call setup time, eliminate
the 1 in 1000 chance that you will accidentally "answer" an incoming call
when trying to place an outgoing call.

Reasons not to migrate: more costly (about $15/month/channel), harder to
configure (I'm a bit intimidated - can't have downtime), if the * server
blows up one cannot simply plug in a $10 handset from Walmart to get some
bit of functionality - MUST use ISDN hardware.

Any experianced opinions on this?

>Brent-

>Echo can occur for all sorts of reasons- analog conversions as someone else
>already mentioned, 4 wire to 2 wire in particular- but could also occur in
>the IP path due to network issues, and can occur on any sort of digital or
>analog circuit due to various electrical or audio components. (one of the
>more commonly neglected causes is poor handsets, that do a bad job of
>isolating the speaker and microphone, or attempt to add sidetone
incorrectly
>(sidetone is the slight echo you should hear of your own voice- it's very
>hard to hear, but without it, you get the feeling that you're talking to a
>dead wire).  Conversion to BRI/PRI is a last step only, in my opinion,
>unless you have other compelling reasons to do so- there's a lot of other
>places to look first.

>If you could describe more of your particular setup, I'd be happy to give
>more detailed description of where the problems might lie.

>-Paul Davidson
> PlanCommunications, LLC


Sincerely,

Brent A. Torrenga
brent.torrenga at torrenga.com

Torrenga Engineering, Inc.
907 Ridge Road
Munster, Indiana 46321-1771

219.836.8918x325 Voice
219.836.1138 Facsimile
www.torrenga.com