Unwanted TLSv1 to SIP Provider

[Michael Moore]

I have an IP authenticated SIP trunk setup between our 3CX and Fusion. They did a capture related to a different issue we were having an were seeing a lot of TLSv1 handshake requests coming from us. I'm trying to figure out how to turn off the secure SIP option for this SIP trunk since it's not supported by the provider.

You can see in the attached screenshot the packets I'm talking about circled. I've deleted the IP's but one is our 3CX and the other is the ITSP's SIP server.

Any help would be great.

 

[YiannisH_3CX]

Hello @Michael Moore

Please check the following post and check if you issue is related to the one there. If so please implement the same solution and let us know if that works
https://www.3cx.com/community/threads/503-certificate-validation-failure-outbound-calls.54273

 

[Michael Moore]

In that reply someone says you can:
"If they support SIP over TCP you can prepend transport-tcp. to your registrar and force the PBX to use TCP to communicate to the provider."
How do you do that? If I can force the 3CX to do that instead of try and connect via TLS that would solve my issue.

 

[YiannisH_3CX]

How do you do that? If I can force the 3CX to do that instead of try and connect via TLS that would solve my issue.

This is what is described in the thread. You need to prepend " transport-tcp." to your registrar to force the trunk to register with TCP instead of TLS
Edit you trunk and adjust the registrar field by prepending " transport-tcp."