I installed asterisk pbx first time. I tested the functions with my PAP-2 box at home. Now, I am trying to send calls to VoIP provider. I tried many of them but none of them has succeeded. Some providers told me that I need to have g729 codec and some told I need to be change my broadband router settings to traverse NAT. Do you know any provider that supports SIP or IAX with GSM or ILBC codec and NAT friendly service because I can’t change the broadband router settings?
you can try asterisk2pstn, they support gsm codec and provide worldwide termination services with very acceptable rates. Online signup is possible from www.asterisk2pstn.com
You can try Voipjet - they will give you 0.25$ for tests.
Please be aware that some of their servers are using g729 - others use all codecs
220.127.116.11 - they are using only G729
I use g711u on that voipjet server all the time, works fine.
Exgn.net support IXA with GSM as a codex. Most providers will support G711 ulaw and alaw
asterisk2pstn gives upto 60 minutes of free test calling, all international.