Hosted VoIP phones will not Register with SIP ALG Disabled and call drop when enabled

[Aodhan]

I have updated to the newest firmware release of Merlin for an Asus rt68u
before I was able to run my VoIP phone to a cloud based PBX server with no issues on the registration. Now I am seeing issues with calls dropping after 30s and when I disable the SIP ALG in the UI the phone will not REG at all. I have also telnet in to the router and set nvram set nf_sip=0 and have the same out come. I am going to set up a tap between my Asus Rt68u and my Motorola SB6141. I will test more to see what I find. Any assistance would be greatly accepted.

 

[davros1999]

Hi

I've noticed in recent builds setting SIP ALG off adds an iptables rule that blocks UDP SIP. See my post: http://www.snbforums.com/threads/issue-with-sip-nat-passthrough-disabled.30761/

I think this is a bug.
I have to manually delete the entry to allow SIP through the router.

In previous builds I found the SIP ALG to be unreliable (I work for a SIP provider so I have experience) so I would recommend turning it off if your provider supports hosted NAT traversal.

I just need to find out how to submit an issue report for the iptables rule...

Cheers
Dave