no voice after call get connected in g729 codec

Hi,
I setup a asterisk environment with the sip protocols and the codec used is g729. But for some calls, after connect there is no voice in the line.
Asterisk - 1.4.21.2

Kindly help me regard to this.
Thanks & Regards,
balasam

Hi

How many licences have you ?

Ian

Hi,
I purchased 151 licenses of g729.
Specification : 64bit
codec_g729a-1.4_3.0.3-nocona.tar.gz
Ouptut of show g729 CLI command.
> show g729
2/4 encoders/decoders of 151 licensed channels are currently in use.

Output of show translation CLI command,
>
> show translation
Translation times between formats (in milliseconds) for one second of data
Source format (Row) Destination format (Columns)
g723 gsm ulaw alaw g726aa12 adpcm slin lpc10 g729 speex ilibc g726 g722
g723 - - - - - - - - - - - - -
gsm - - 2 2 2 2 1 4 9 - - 2 -
ulaw - 2 - 1 2 2 1 4 9 - - 2 -
alaw - 2 1 - 2 2 1 4 9 - - 2 -
g7266aa12 - 2 2 2 - 2 1 4 9 - - 1 -
adpcm - 2 2 2 2 - 1 4 9 - - 2 -
slin - 1 1 1 1 1 - 3 8 - - 1 -
lpc10 - 3 3 3 3 3 2 - 10 - - 3 -
g729 - 2 2 2 2 2 1 4 - - - 2 -
speex - - - - - - - - - - - - -
ilibc - - - - - - - - - - - - -
g726 - 2 2 2 1 2 1 4 9 - - - -
g722 - - - - - - - - - - - - -



and the phone which i am using is Cisco 7940 and it support the g729 codec. The problem is 30% of calls are no voice calls.Now i am running short of time deadline. So Please Kindly direct me to make it work properly.

Thanks & Regards,
balasam.