Ive been trying for over 24 hours to get a Cisco 7945g IP Phone to talk to Asterisk.
The phone is running the SIP firmware and ive got the config XML files on a local TFTP server.
Asterisk has a public IP and is in a datacentre.
The phone is behind a NAT in my office.
I've found that the only way I can get the phone to authenticate with Asterisk, is by setting NAT=no in the sip.conf file for the peer.
Otherwise, I just see UNAUTHORIZED in SIP Debug.
However, when i set NAT=no, there is only one way audio.
I've got a Polycom phone which is also behind the NAT in my office, and that works fine.
I've tried mapping ports, but that didnt seem to help.