My Voice (VoIP) Gateway is plugged in via a firewall/router, and my VoIP calls always disconnect at exactly 10 minutes. Why does this occur? Every 10 minutes the network will audit (by sending a SIP INVITE) both ends of an active call to ensure they are still responding. If your VoIP client/CPE does not respond, or if the response is incorrect, it will result in the call being disconnected. The device should respond with „200 OK. message. The network performs these audits to protect users against scenarios that could result in excessive call charges, and is a standard part of the SIP protocol to ensure both ends of the call are still there at regular intervals. Why would my CPE not respond correctly? This could be caused by over aggressive firewalls with packet inspection, as these will block all outbound UDP packets, resulting in no message being sent in response. Additionally, if your setup involves NAT it may be failing if your equipment/software is trying to cover up the presence of NAT, and may rewrite the message content in a way that it cannot be recognized once it reaches your SIP-UA. How can I resolve the issue? Obtain updated firmware for your router Most likely it is your modem/router which will normally be doing the authentication, however if you have a bridged modem, a third device such as a wireless router or ATA may handle the authentication/NAT. Ensure you are running the latest firmware for your device from the manufacturer.s website. Contact the manufacturer for technical support If you have the latest firmware and you still experience problems, try contacting your router manufacturer to see if they have firmware to fix the issue. If you haven.t been able to get assistance from the manufacturer, there are a couple of band aid solutions to try; Port Forwarding We recommend port forwarding UDP ports 5060 and 16384 - 20384 to the IP address of your ATA. We would recommend you give your ATA a local static IP address, as your port forwarding rules require the IP address of your ATA. Dynamically assigned addresses are subject to change and may render your rules useless. DMZ If you can't get port forwarding working or are just seeking a quick fix, then DMZ is a means of forwarding all unused ports to your ATA. It is simpler than port forwarding, but less secure. To set-up DMZ, we would recommend you give your ATA a static IP address and add this address to the DMZ field of your router. Belkin and Other Voice/VoIP Routers SIP ALG If you are running a router/modem in front of your voice gateway device that also supports VoIP, you should also check and ensure you disable, or turn off “SIP ALG” method as below as this will effect your VoIP connection on your additional Voice device as it is trying to act as the VoIP gatway. It is also good to change the port of the actual SIP device sitting behind the router that you are using to register with to 5070 as this can sometimes get around the sip-nat/sip-alg interference issues. Different hardware has different ways of doing this (refer to manufacturers instructions) however, usually it.s as simple as appending „:5070. to the end of the sip server address – ie, „sip.wa.iinet.net.au. becomes „sip.wa.iinet.net.au:5070..