[Asterisk-Users] Codecs and bandwidth

[Rich Adamson]

> If you include down + up, yes, it's actually about 150-160 using uLaw + 
> IP/UDP/RTP/signaling overhead.  But that's a little misleading, I think. 
> 
> 1/2 of that (~75-80) is down, 1/2 of that (~75-80) is up.  So if you 
> have, say, a 1.5Mbps down/384 up DSL connection, you can do up to 4 
> calls simultaneously.  80*4 = 320.  You'd be using 320kbps down and 
> 320kbps up, which is within your 1500kbps down / 384 kbps up.
> 
> Someone please correct me if I'm wrong.

That analysis is right, however seldom will the math work out exactly
like real world usage. In all likelihood, other dsl traffic will consume
a part of that bandwidth and two or maybe three calls might be usable.
Implementing Quality of Service (QoS) on the outbound data flow might
increase the probability of having more usable simultanous calls though.