[Asterisk-Users] iaxtel and jitterbuffer

[Rich Adamson]

> > Had this problem earlier this week - ensure 'trunk=no' in iax.conf if you're
> > using fairly current CVS code. There is something not right w/the trunking
> > that causes choppy sound. See the wiki for more info.
> 
> I am using current CVS code and I have trunk=no.  Still sounds crappy.  I need
> to check with my ISP and make sure they aren't throttling in that range.  I'm
> only getting about 4.5Kbps of throughput...  Any available codecs that can use
> that level of bandwidth?
 
I do a lot of work with companies throughout the US on network performance
and we _frequently_ run into routers, switches, servers, etc, that are
allowed to auto-negotiate their half vs full duplex nic interfaces. About
50% of the time, systems will get it wrong as there are no standards as
to how the negotiation should be done.

A recent case this past week indicated that data flow between two servers
on the same layer-2 network was around 400 kbps when it should have been
able to sustain at least 80 meg.

You might double check each of your ethernet interfaces to ensure duplex
settings are correct. If not at full duplex all the way through, you'll
run into the strangeness you're seeing under varying traffic loads.