[asterisk-dev] RTP trunking - 58% savings on media bandwidth?

[Jared Smith]

On Thu, 2008-12-18 at 01:33 -0800, Maxim Sobolev wrote:
> In many cases you can get sufficient saving 
> by just increasing RTP payload size. By going from 10ms to 90ms you
> get about 70% saving on G.729 and it works with any standard UA, no 
> additional support is required.

This is the method I initially tried when I invented IAX2 trunking, but
I found that it doesn't scale nearly as well as combining payloads from
concurrent calls into the same UDP packet.  In other words, scaling
across concurrent calls scales better than scaling across time.

The company I was working for when I developed IAX2 trunking had an
instant savings of between $20,000 and $70,000 USD per month on their
telecom costs (depending on their voice traffic), and have been actively
using it since 2002.

I don't see why we shouldn't be able to get the same kinds of gains over
RTP as well.  To be completely honest, I'm surprised nobody has done it
before now.


-- 
Jared Smith
Training Manager
Digium, Inc.