I have this problem: SIP will not work with this router. Configuring NAT, virtual server, etc., tried for many hours, but it will not work?? The (Siemens S450IP) will connect to the SIP servers, will authenticate, callsetup will go ok, but I cannot get an answer message (this is the C7 name, do not know the SIP equivalent), the called Bnumber picks up, I still hear the ringtone, so for some reason no speech path is created?? Is there anyone who has an idea why, or better have a solution???
Without SIP this (otherwise good router) is only to be used as an accesspoint......
Another thing, putting back my old router (WRT150N, with only port 5060 forwarded), works perfect. So modem etc are not the problem...
(DIR-825, B1, firmware 2.01EU)