[Asterisk-Users] frames/packet

[Steve Underwood]

Paul Lambert wrote:

>"Not yet." implies that it is coming. 
>
Look at the latency it causes, and you will see its not that useful.

>I know it would help on Internet
>connections such as fixed wireless and cable modem where packet rate is
>an issue. 20ms translates to 50 packets/sec. 
>
30ms per block codec aren't bad. Going beyond that gets nasty. 2 x 20ms 
blocks per packet about the most people will tolerate.

>I believe cable modem
>upstream packet rates cap at 150-200 packets/sec. G729 gets the bit rate
>down to 8kbits. 
>
G.729 gets the rate down to 8kbps. Then RTP puts it back up to several 
times that.

>So based on a bit rate of 256K the theory is that the
>link could handle 32 calls. But, that would produce packets coming out
>at a rate of 1600 packets/sec beyond the limitation of most Internet
>connections including a T1.
>  
>
A T1 has no particular packet limit. It is just limited to 1544kbps. 
Some routers choke on large numbers of small packets, but that is not a 
T1 problem.

Regards,
Steve