Solved Telnyx TLS trunk connection with V18

[Chris Ruffin]

It looks like 3CX doesn't try to connect to my Telnyx SIP credential-based trunk if I have the transport set to TLS (sip.telnyx.com port 5061). I can't find any useful debug information in Events or in the Activity Log. If I switch the same trunk to UDP and port 5060, everything works fine. I did a pcap capture and did a refresh registration, but there is no traffic captured to the trunk/port. It seems like there is some software glitch but I'm not able to find any log message. Is anyone using a credential based SIP trunk with TLS with success on V18?

 

[Evolute IT]

It looks like 3CX doesn't try to connect to my Telnyx SIP credential-based trunk if I have the transport set to TLS (sip.telnyx.com port 5061). I can't find any useful debug information in Events or in the Activity Log. If I switch the same trunk to UDP and port 5060, everything works fine. I did a pcap capture and did a refresh registration, but there is no traffic captured to the trunk/port. It seems like there is some software glitch but I'm not able to find any log message. Is anyone using a credential based SIP trunk with TLS with success on V18?

Have you uploaded the root certificate in the appropriate field?

https://www.3cx.com/docs/telnyx-voip-provider/#h.7ovuyic3movz

 

[Chris Ruffin]

Thank you fo

Have you uploaded the root certificate in the appropriate field?

https://www.3cx.com/docs/telnyx-voip-provider/#h.7ovuyic3movz

Thank you for the reply. I did upload the certificate that I had found from Telnyx support documentation. I tried this one as well but got the same result.

 

[Evolute IT]

Thank you fo

Thank you for the reply. I did upload the certificate that I had found from Telnyx support documentation. I tried this one as well but got the same result.

Strange. We use this exact setup (although with Telnyx.ca) and it works perfectly.

Can you upload screenshots of your trunk config in 3CX and Telnyx connection config as well? Be sure to hide any credentials or URLs.

 

[YiannisH_3CX]

Make sure that Auto Discovery is enabled next to the registrar address and you do not have a manual port there as that limits the DNS queries the PBX is making.

 

[Chris Ruffin]

Thank you, attached.

 

[Chris Ruffin]

Make sure that Auto Discovery is enabled next to the registrar address and you do not have a manual port there as that limits the DNS queries the PBX is making.

Thank you YiannisH, I tried it but got the same results.

 

[YiannisH_3CX]

Ok then i would recommend starting a capture and while running restart the SIP server service of 3CX. Once its back up give it a minute and stop the capture. Filter with the Telnyx IP Address and see if there is any traffic. Also check the activity log for errors.

 

[Chris Ruffin]

I don't see any traffic to port 5061. It lists "Resolving target Telnyx LLC Fax TLS" in the activity log, but no traffic goes out on 5061.

 

[YiannisH_3CX]

Can you navigate to Security / Secure SIP and see if the "Secure SIP/TLS" option is enabled and if the certificate and key values are populated?

 

[Chris Ruffin]

Can you navigate to Security / Secure SIP and see if the "Secure SIP/TLS" option is enabled and if the certificate and key values are populated?

Its not. Should it be? I did disable this because I thought it was part of the teams setup I did, but then dismantled. I wanted to use the auto-renewing Let's Encrypt keys for millcore.sc.3cx.us.

 

[YiannisH_3CX]

It should be yes. TLS does not work if that option is disabled. Those are the certificates for your 3CX FQDN. You need to repopulate those values. Did you save them by any chance?

 

[Chris Ruffin]

I don't think I have them if they were removed. Is it the same as the ones under the nginx directory?

 

[YiannisH_3CX]

No they are the ones under /var/lib/3cxpbx/Instance1/Bin/Cert and are the domain_cert and domail_key that match your domain name

 

[Chris Ruffin]

Unbelievable. I was able to restore those certificates and it immediately successfully registered. All working now! Thank you!!!

 

[YiannisH_3CX]

Glad to see the issue has been resolved.