[Asterisk-Users] IAX Codec

[Martin Roy]

I have 2 Asterisk servers connected with IAX. It's working fine I can 
call an extension from one phone in an office to another phone in the 
other office. The only problem I have is lagging. What codec should I 
use? I have Cisco phones 7960 on both end. Currently in the IAX trunk I 
configured it to disallow all and use GSM only. In my sip config of each 
phone I use disallow all and allow ulaw and alaw only.

I see that the Cisco phone support G.729a, G.711u and G.711a codecs.

I know that Digium is selling G.729 codec on there website. Should I get 
that to fix my problem?

The less bandwitdh the codec takes over the Internet the better chance I 
have that it will work fine I presume.

The maximum upload speed I can reach is 64k/sec so 512kbits. But that's 
if there's nothing else using the internet. I see that G.729 use 8kbps 
per call which seems quite small. The sound quality is good enough for 
SIP to SIP phones over the Net?

Thanks

Martin