Dear all, just tested a 3cx 15.5 runing on Windows 2008 R2 server , with 1 sip trunk to voip provider Mobiltel in Bulgaria. Connectio to provider is done via separate LAN card via vlan from provider. Authentication is IP based from voip provider. Еverything is fine exept when we make OUTGOING call AND remote party doesn't have activity on microphone. In this scenario i hear clearly that voice activity detection supress a noice. Thise lead to inconvenience - after long pause first letters of remote party word are missed. I try to disable on phones VAD ,but it doesn't help. I try also with software phone from 3CX - still the same issue. All phones are in sepate vlan with qos, there is no losses All phones has Alaw codec which is the same for SIp trunk Alaw (no transcoding) When I got a INCOMING call , it can be heared that there is no voice activity detection and calls are perfect. I've got from provider information following information: voip signaling should be send to 188.8.131.52 and voip media (rtp) should be send to 184.108.40.206 I've separate LAN card with private IP from voip provider 10.253.2.XX. This has been added to SIP configuration of trunk for IP which will be used, and also added in localsubnets (to avoid nat) At the moment I think that voip media 220.127.116.11 should be used somewhere in SIp trunk, or I need to disable this voice activity detection somewhere. What can be the issue ?