Configure AT&T U-Verse 3800HGV-B Router for VOIP With Other Provider: SIP ALG Issue
I'm using an Obi202 unit and PhonePower as my VOIP. I recently switched to PhonePower since support for Google Voice is ending. However, I'm having problems getting the configuration to work: basically there is one-way audio. I cannot hear the person calling me, but (s)he can hear me. This problem affects inbound and outbound calls.
I have followed all the instructions regarding port-forwarding and this made no difference. The AT&T 3800HGV-B router does not allow me to disable SIP ALG. Is there a newer model that allows me to configure this setting?
I also have a secondary NETGEAR router which I put in the DMZplus zone. I tried hooking the Obi202 to the NETGEAR router, disabling SIP ALG, and applying port-forwarding and that too made no difference.
Looking at the router logs I'm not seeing packets being dropped so it appears the port-forwarding and or DMZ zone is working. I have not tried putting the Obi202 unit as the DMZplus "computer" on the AT&T router because then I would have to disable my NETGEAR router.
Any help is appreciated. Is the fact that I cannot disable SIP ALG in the AT&T router mean that it still is an issue when I hook the Obi202 to the NETGEAR router which does have it disabled?
When putting the device in DMZ mode, it should bypass the SIP ALG protocol. If you could please try removing your Netgear router and connecting the Obi202 directly to the 3800 and putting it in DMZ mode, this will help isolate any other devices that may be causing issues.
Let us know how it goes.
If you encounter any issues with your service or equipment, I recommend checking out our Troubleshoot & Resolve solutions to help diagnose the issue.
*I am an AT&T employee, and the postings on this site are my own and don't necessarily represent AT&T's position, strategies or opinions.
The AT&T U-verse router has an option to select an "Application Type" when setting up port forwarding. Setting an "Application Type" is optional - the value can be blank. When I initially setup port forwarding I had chosen the application type of "SIP Telephony".
However, upon checking the AT&T U-Verse router NAT logs I noticed that the log entries with port-forwarding rules stated "SIP ALG" which means the very thing we did not want enabled was being applied to port-forwarding.
I removed the "SIP Telephony" application type from all my port-forward settings for the Obi202 device in the AT&T U-Verse router. Suddenly, everything started working for two-way audio. I can hear the caller and (s)he can hear me, and, it works for incoming and outgoing calls.
I previously mentioned that I have a secondary NETGEAR router in the DMZplus zone of my AT&T U-Verse router. Since the DMZplus zone is occupied by this router, I cannot put my Obi202 device there. I had tried putting the Obi202 on the NETGEAR router and it did not work even though I had disabled "SIP ALG" and applied port-forwarding on the NETGEAR router. However, my guess is that the packets were already "re-written" by the AT&T U-Verse router using "SIP ALG" prior to them being "forwarded" to the NETGEAR router.
I would like AT&T to provide detailed documentation as to what each of the "Application Type" settings change in the port-forwarding operations.
Anyway, the Obi202 device is now working with Phone Power and the AT&T U-Verse router. The key was not to choose an "Application Type" when setting up port-forwarding.