I use a Dlink DVG-1120S (flashed from 1120M) as my voip gateway. It is connected behind my 2Wire 2701HG-B AT&T gateway-router. My desktop and the VOIP gateway are connected to two lan ports in the router. The firewall has been configured in the router to support this setting.
I do not have any issues in making/receiving calls using this setup. But, when I switch off my desktop (which is connected to the router's LAN port) the VOPI gateway loses its registration after an hour. The reg status lights that indicates its registration with the SIP server, starts blinking, instead of being "solid green".
My view is that since the computer and the VOIP gateway are connected to two different LAN ports on the router, these should act independently. That is, even if the computer is turned off, the voip gateway should function properly as long as the router and its broadband connections are up. I have been exploring various options in my router and the voip gateway for the last 6 months. But couldnt figure out why this happens. Has any one else seen this/know a way to resolve this issue?
My voip gateway is assigned a DMZ-plus mode in the router firewall ( I know its not safe, but I find that it works right now. I will make changes when I find time)
Server FQDN : enabled
Domain Name : proxy01.sipphone.com
Port : 5060
Service Domain :
URL Format : SIP-URL
User Parameter Phone : disabled
Timer T2 4 sec
Register Expiration 1800 sec
Session Expires 180 sec
Min-SE : 180 sec
Session Expires Refresher uac