Register a Remote Extension with OBi

[QBZappy]

I recently replaced my  router from an Asus WL-500gP v2 with an Asus RT-N16. I had the ability to register the OBi as a remote extenstion to a Grandstream 5024 PBX using a DynDNS name. Both routers have been flashed with Tomato firmware.

Problem:
I can no longer register a remote extension with "abc.dyndns.com"

I have compared the settings from the two routers trying to spot a reason why the new router will not allow the OBi to connect to the PBX witout any success. It worked under the Asus WL-500gP v2. I see no reason why it should not work with the Asus RT-N16.

Related to above, I can no longer make extension call using sip URI "114@abc.dyndns.com:5060"

Can someone suggest something I could try.

[QBZappy]

Well, I'll reply to myself with the solution to my problem of registering a remote extension if it can help others.

Summary:
My router setup new Asus RT-N16 flashed with Tomato firmware (v1.28.9054 MIPSR2-beta K26 USB vpn3.6)

Problem:
Remote registration with DynDNS name not connecting to my Grandstream PBX.

Solution that fixed my problem:
1) Changed SIP port in PBX to 5064
2) Port forwarded ports 1-65,000 UDP&TCP to PBX
3) Rebooted everything for good measure (Router, PBX. OBi)

Bingo it registered.

4) Changed SIP port back to 5060
5) Changed Port forwarded ports back to OBi default ports
6) Rebooted everything for good measure (Router, PBX. OBi)

Everything still registered over WAN with DynDNS name, including softphones.

Looks like all or a combination of the above opened up the firewall in the router. This may possibly work with any other router having similar issue.

[OBiSupport]

Thanks for sharing, QBZappy, interesting...