SIP Trunk Re-Authenticate Fail

[CTA-Tech]

Hi All,

I have a strange one here. I have a SIP trunk setup in the 3cx system which is "internode". I know this is not supported so "Generic" is used as the service.

I am able to add the trunk successfully and it all works and stays online until it comes time to "re-authenticate". When this occurs the trunk errors advising that "Registration at INTERNODE SIP TRUNK has failed. Destination (sip:203.2.134.1:5060;transport=TCP;lr) is not reachable, DNS error resolving FQDN, or service is not available.".

I have checked with Internode and they confirm they can see us sending them registration requests with auth (w/auth) however when the issue occurs they are sending us a register packet with out auth which is fine but as it has no auth details we will reject it with a 401 unauthorised and so the customer should then resend the register packet but this time with auth (w/auth) but the customer does not do this so the registration does not renew and the trunk becomes unregistered when the expiry timer on the last good registration expires.

Has anyone seen or know if there is a setting that i can change to fix this?

NOTE: i have tried UDP as well for communication with the exact same issue. I have confirmed that the settings are all correct and i have reviewed the firewall mutltiple times looking at Flood protection and other items mentioned in the forums and it looks fine.

Any suggestions would help

Thanks in advanced,
Joe

 

[YiannisH_3CX]

Hi @CTA-Tech

Unfortunately your issue will need some investigating as the only way to check what is happening is by running a packet capture and leaving it running until the issue occurs. As this may be random you may need to use tshark to prevent the machine from being overwhelmed from the size of the capture.
Before you do anything however make sure that you run the firewall checker and that passes all tests to minimize the chance of this being a firewall issue.

 

[CTA-Tech]

Hi,

Thanks for your reply.

I have configured the Firewall as per the instructions for the watchguard, however it does fail its "Full Cone" testing.

I have also run a Wireshark and can see that re-registration is working over and over but for some reason it just stops getting a response from the SIP server despite it sending the same "Request: REGISTER " packet that it has received responses for previously.

I think ill look into the Firewall again and see if i can work out whats going on their as it may be stopping these after some time.

Thanks for reply.

Regards,