SIP ALG stands for Application Layer Gateway. Certain routers come with internet service provider is configured to turn on by default. In that case, you might encounter connecting to our SIP server.
Some of the settings configured on the client-side (STUN, TURN, ICE), others are in the server-side (Proxy RTP as RtpProxy, MediaProxy).
Below are some guidelines to tun it off.
Maxis's Router :
1. Login to your router. Normally, the IP address is 192.168.0.1
2. user name and password is printed at back of your router
3. After logging in, go to Firewall > ALG and turn off RTSP and click on apply changes
TP Link's Router :
1. Login to your router. Normally, the IP address is 192.168.0.1
2. After logging in to the router, go to Advanced > Nat Forwarding and disable RTSP ALG