I am facing a small problem using asterisk, at the time of conf. the voice becomes very low, the called party cannot hear the third party and vice versa, is there anything that can be done to increase voice in the conference.
need more info - what type of hardware are you using, what types of channels are connecting to the conference?
I am using a Xeon server as an asterisk server (asterisk 1.2.4) and moreover the SIP phone is Grand Stream BOX with codec as Alaw
And calling through IAX trunks with codec as GSM