I have a new install and the customer is complaining that they hear noise on all calls, no matter if it is internal or external, desk phones or softphones. The noise is only present when the user is speaking, not the remote side. The remote side does not hear the noise, only the local user.
We are using Asterisk .1.8.11-cert8 on a CentOS 6 machine with a Digium AEX800 card and DAHDI 2.6.1. I really do not know how this noise is generated. Where can I look? Why would a SIP to SIP call have this noise?