[asterisk-users] what can we do with lost voice packet on a congestioned VPN?

[Julio Arruda]

nik600 wrote:
> Hi to all
> in a scenario where:
> 
> - the bandwith is shared with other traffic (HTTP,VPN,ecc)
> - the PBX is on a remote VPN peer
> - due to many reasons Qos is not usable
> 
> There is a IAX trunk between 2 Asterisk 1.4 i've tried different
> codecs (ulaw,alaw,gsm) but the main problem still remain the same: too
> many voice packet get lost.
> 
> The main problem is surely on the network, but the strange thing is
> that on the same network there is an H323 trunk from an Alcatel and a
> Cisco CCM (using g711 codec) and in that case the voice isn't so bad!
> 
> i've tried to enable jitterbuffer but i can't notice some difference.
> 
I think if you have packet loss, a jitterbuffer would make no difference..
SOmething like PLC (packet loss concealment maybe ?) come to mind ?

Have you tried ILBC ? or SPEEX ? G.711 should be resilient, but I 
understand iLBC and Speex both have some tricks to handle PLC.
Also, GIPS had some kind of magic sauce they offered (code-wise) to 
offer PLC to vendors ??

> Is there something else that i can do?
> 
> Thanks to all
>