[asterisk-users] Re: VOIP Bandwidth questions

[Eric "ManxPower" Wieling]

Vikki wrote:
> I think vonage is using g723.1 which requires 6.4kbps voice bandwidth
> compared to g711 - 64kbps.
> 
> For SIP to SIP calls, RTP doesn't necessarily goes thru the server. Only
> Signalling goes to the servers. This means no bandwidht usage for the
> provider.
> For SIP to PSTN calls, it has to goes thru a media gateway (owned by the
> provider) which may be seperate from the sip server.

I imagine that most of Vonage's customers are behind NAT and direct RTP 
(re-invites) don't work well with the endpoints behind NAT.