I'm testing a SIP solution for a client and can barely get beyond first base. An answer to this simple question will help heaps:
Does the DSL Router I'm using (Dlink DSL-G604T) have to specifically support SIP for it to allow pass thru of SIP traffic from LAN clients to public SIP servers? Or is it sufficient to open UDP port 5060? My router was firewall & NAT enabled and port 5060 open for UDP, but registration of the SIP softphone client with the sip server fails. I can telnet to the SIP server on 5060, so something's getting through, but does that demonstrate that SIP should also work? Or do I need a new router?