PBX 200 Ok not sending

[karjune]

We have installed a 3CX v20 ok digital ocean about 10 months ago. We used a SIP provider for external calling since then too. Our SIP trunk worked great for the last 10 months until today when our trunk shows unregistered for hours then registered for a few minutes before going unregistered again. A call with the SP showed that 3CX isn't sending '200 OK' to the provider. Not sure how to resolve this via Digital Ocean POV. Any suggestion is appreciated.

 

[KyriacosS_3CX]

Hello,

Is this a Supported SIP provider, with the build in template? Have you made a packet capture to see if indeed the 200 OK is not being sent?

 

[TheodorosG_3CX]

Further to @KyriacosS_3CX reply, does your firewall checker pass successfully?