Brent Torrenga
2006-Feb-28 08:52 UTC
[Asterisk-Users] Re: Echo and other reasons to migrate to BRI from POTS? Was (Echo on PRI/BRI?)
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 sidetoneincorrectly>(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, LLCSincerely, Brent A. Torrenga brent.torrenga@torrenga.com Torrenga Engineering, Inc. 907 Ridge Road Munster, Indiana 46321-1771 219.836.8918x325 Voice 219.836.1138 Facsimile www.torrenga.com