Cisco 7912 Asterisk 1.4 VAD problem

If you have problem with speech quality in Asterisk, check this message in log files:

Comfort noise support incomplete in Asterisk (RFC 3389). Please turn off on client if possible. Client IP: XX.XX.XX.XX


Go to client phone settings:
Go to WEB --> Audio Parameters --> AudioMode --> 0x00000010

More info about  AudioMode bits:

be sure that AudioMode is set to 0x00000010 rather than 0x00000011.
Note that the bits of the Audio Parameters also set the DTMF method used, as follows:
Bit 0: G.711 silence suppression:
–0=Disable.
–1=Enable.
Bits 1-3: Reserved.
Bits 4-5: DTMF transmission method:
–0=Always inband.
–1=Negotiated via SDP.
–2=Always out-of-band.
Bits 6-31: Reserved.

1 = G.711A-law
2 = G.711u-law
3 = G.729a

http://www.voip-info.org/wiki/view/Cisco+7905/7912+IP+Phones