[Freeswitch-users] FS behind NAT encounter no audio

Hi, I could make a call within NAT without any problem. When I made a call from internet, I got no audio. I have read the document http://wiki.freeswitch.org/wiki/NAT_Traversal and set the parameters. vars.xml <X-PRE-PROCESS cmd="set" data="bind_server_ip=my.server.ip"/> <X-PRE-PROCESS cmd="set" data="external_sip_ip=my.server.ip"/> <X-PRE-PROCESS cmd="set" data="external_rtp_ip=my.server.ip"/> internal.xml <param name="ext-rtp-ip" value="$${external_rtp_ip}"/> external.xml <param name="ext-sip-ip" value="$${external_sip_ip}"/> <param name="ext-rtp-ip" value="$${external_rtp_ip}"/> Any advice? Thanks. Jimmy