I am trying to configure a Cisco SPA8000 to function as a SIP ATA behind a RV220W router. I cannot seem to get port forwarding working or otherwise allow the SIP traffic to the SPA8000. When I replace the RV220W with another router / firewall everything works fine, but when I put in the RV220W I am not able to register etc. I have been over and over the manual and "yes" I have the SIP ALG enabled. Here is my setup:
Internet => RV220W (public) => SPA8000 (private)
Can anyone suggest anything please?
P.S. on hold for nearly 3 hours waiting for Cisco support!!
Yes, I was able to get this working and it has been doing extremely well for about 4 months. The key in my case was to make sure the SIP AGL was ENABLED. The problem was that the service provider's SBC was seeing a non-routable IP address in the SIP header and was requiring a shorter registration interval than the endpoint. The result was that the SBC would eventually deny the connection when the registrations got out of synch.
I can recommend this configuration now and for high SIP traffic (in excess of 12000 minutes per month on 5 channels).