g.711 vs g.729a

[ctaranto]

I didn't want to bother support with this question (as my service is working fine).

I recently received a PAP2T as a replacement for a (defective) RT31P2. I also had a PAP2T with my previous VoIP provider (VoicePulse). The RT's web interface is very bland compared to the wealth of information the PAP2T provides. That said, I don't know what the RT uses...

The PAP2T with VOIPo is using the g.729a compression codec. My previous provider was using the g.711a codec (again, using the same kind of ATA). I did a little research this morning on the differences. The 729 is newer, but does a lot more compression, and is quite a complex algorithm, mixing synthesized data and the actual voice data. The 711 is the traditional codec which does very little compression and passes along the actual voice.

The 729 uses only 8kbps of upstream bandwidth. The 711, on the other hand, uses 64kbps of upstream bandwidth.

Logic says that the 711 will sound better since there's less compression, and it's sending along the voice without much fuss. But on a call with my wife this morning, I really couldn't determine a difference. Granted at home we have cordless phone, and the phones at my work are also VoIP. Bandwidth for me isn't a big deal (Comcast 12/2 service).

I'm curious if anyone has opinions on the quality of 711 vs 729, issues with 729 regarding faxing, DTMF, etc. Is there a way to switch to 711 if one wanted to (this is more for VOIPo support that others here)?

Update:
I found this useful link: Voice Over IP - Per Connection Bandwidth. Actual usage of 711 is ~87kbps, 729 is ~31kbps.


Thanks,

-Craig