[asterisk-users] Noise on phones while speaking...

[Joshua Colp]

Carlos Chavez wrote:
> The card itself does not have hardware echo cancellation so we use MG2.
> I am not fixated on the card because this should not affect a SIP to SIP
> internal call unless the card is really defective and provides bad
> timing to Asterisk.

Actually when bridging channels Asterisk acts as either a low level 
packet router ("Packet2Packet" or "Local" bridge - RTP packet is read 
in, minimally modified, and immediately sent back out) or as a higher 
level media forwarder (RTP packet is read in, dissected some, stuffed 
into internal data structure, shipped off to other channel, RTP header 
added, packet sent - although monitoring/recording/transcoding is 
involved it's in that list of operations too). Timing from an external 
source isn't used. So really, I'm fairly certain it's something to do 
with your phones. If you could post a short snippet of a phone calling 
another and the bridge that occurs I could be more certain.

Cheers,

-- 
Joshua Colp
Digium, Inc. | Senior Software Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at:  www.digium.com  & www.asterisk.org