Dear all: I have questions about VAD and echo cancellation. My FS is Version 1.0.head (git-) under Windows XP. My soft-phone is X-Lite. I use earphones and microphones for sip 1 which means the talking and hearing are separated; on the other hand, I use NB for sip 2 which makes the talking and hearing in the same place. Sip 1 (1000) calls sip 2 (1001) via FS. When I say something via sip 1, the echo will occur, and the echo will only occur on sip 1. How do I cancel the echo? Buy a hardware card or something else? I have two gateways which are Wellgate2644 and ata171m. Please give me some suggestions. When I enabled VAD, I found something strange. In the start of the session, I can hear the noise and echo on sip 1. If I say something via sip 2, the echo and the noise will disappear. Then the echo will not occur on sip 1 only in a short time, about several seconds. The echo and the noise will occur gradually if I say something via sip1. Is it a normal situation? Sincerely yours, Thisjoy.