SPA504G Codec Negotiation Problems.

[Hitirvine]

I’ve got a SPA504G with Asterisk PBX and broadband.com SIP service. I can recieve calls fine on the handset, but when I make outbound calls, about half of the calls have one way audio or no-way audio. When I have audio problems, I can hit the hold button and then imediatly take the call off hold and that usually solves the audio problems.

The phone HW ver, is 1.0.3 and SW ver. 7.5.1a.

I have tried putting G729a as prefered codec and ulaw as secondary, and also ulaw prefered and G729a secondary, makes no difference.

Any ideas?

Thanks

[Dan Miley]

usually one way audio is caused by a nat or firewall device between the call manager and the phone.

Does your firewall have sip-alg (application layer gateway) or sip fixup  enabled?

does the phone do the same thing when on the same network as the asterix server?

You can also go into the sip tab and NAT Support              Parameters to setup a STUN server, Search for nat support in the admin guide.

Dan