[Asterisk-Users] audio outband bad quality

[Pol]

I'm using asterisk as a sip client with a sip proxy server... I've made 
the pertinent extensions and I've configured the sip.conf correctly or I 
think so..

I'm using x-lite as a client and when I ring to a public telephone 
through proxy, the arriving sound it's perfect but the sound I send is 
very bad, they hear me like a robot and distorted.

Anyone know what's the problem?

Thank you very much.

Pol.