Having an issue with some Cisco IP 7941 Devices,
1. There is no NAT
2. All Ports are open between the SIP Server and the Phone Devices
3. NAT is set to NO in the SIP Config.
I have a few Cisco 7941 Devices that registered up to a Elastix Server perfectly. Outbound calls are fine no problem, RTP is going through great.
Inbound Calls are not working, I've narrowed down the problem to the fact that the 7941 inbound control port is 5060 however it registers with the server on a high UDP Port.
Asterisk tries to talk back to the phone on the high port rather than 5060. By setting qualify to no and doing a SIP Debug I was able to see the behaviour:
SIP Debug Below:
Retransmitting #6 (no NAT) to 220.127.116.11:49161:
INVITE sip:firstname.lastname@example.org:49161;transport=udp SIP/2.0
SIP Show Peers Below:
214/214 18.104.22.168 D A 49161 Unmonitored
As you can see above asterisk is trying to talk to the phone on the High Port that the phone originally registered with. However Asterisk is talking back to 5060 ok for Register requests because I saw the response go back to 5060. (Due to nat=no in the sip config)
It is only inbound calls to the device that it tries to communicate on the high port rather than the register port of 5060.
Any idea on how to force asterisk to communicate with the device on 5060?