voip softphone behind a linksys home router - one way voice

[adavenport]

Either a softphone or a 7960 works when connected directly to a users DSL modem, but behind this particular linksys router it results in no inbound voice stream.

I have to assume that this particular linksys router/fw is firewalling off the returned udp stream. We have tried putting the PC at a fixed address, putting it in the DMZ, as well as setting all udp inbound ports to point to the internal address. Nothing seems to work.

At other external locations, this setup, without any special stuff works fine. I have come to the conclusion that this is specific to this particular model of router/firewall.

The device is a Linksys BEFW11S4, not the more common WRT54G series.

Anyone have any suggestions? My next step is to bring it back to our lab where we can do packet captures.

Roger

[budfox128]

I have this same Linksys router and it works fine with a SIP based IPT using a 7960 and a softphone. With no modifications to the Linksys whatsoever. I have used the phones with SIP services such as FWD and SIPPhone as well as connecting to my own servers. You just have to use STUN or a SIP outbound proxy server.

I believe you are correct though and that the DMZ and port forwarding doesn't work on this router at all. I have tried it and nothing works. I believe the OS is faulty. I have tried using a couple of different versions of the firmware and none work.

[adavenport]

Not running SIP. Call setup is done via CCM (v4.x I think, although I'm not the sysmgr on it). I think I'm going to suggest they get a different router. I've used the Linksys WRT series and they are known to work.

Thanks for your input.

Roger