connect to NAS over a notwork with a voip

[m.tounsi]

Hi;

I have the following scheme:

Pc--->V90 modem--->PABX--->router 3662------router 3662-----PABX----modem v90------>Access server (cisco 2620 with asynch port & integrated modem).

When I use a default codec G729 in the dial peer ,the call can not be established but When i use the codec G711 the call can be done & i connect to the NAS.

What can I do in configuration if I want to connect to the NAS with G729 codec.

Thanks.

[beth-martin]

Some of these URLS should help you troubleshoot:

http://www.cisco.com/warp/public/788/AVVID/audio_decision.html

http://www.cisco.com/warp/public/788/voip/codec_complexity.html

http://www.cisco.com/warp/public/788/voip/voip_debugcalls.html

[yraps]

Data transmission (modem) is very sensitive for voice fluctuation and any lines disturbances.

The Modem connection is based on handshake, in any part during the transmission if you have a slightest interference in the middle the connection is been lost. Both Modems are out of synch.

Thus, each voice sample that is been decompresses and compresses, according to G.729 characteristics, you are subject to loose piece of information. G.711 in hence works well because it doesn't involve compression at all.

Regards,