I’ve never used Asterisk (to my knowledge) and know very little about it.
I am trying to assist someone having TLS Client and Server issues with Asterisk. us-east-va.sip.flowroute.com:443 seems to be something in the middle.
What TLS Certificates are required and where in the model?
I also have found and read TLS client certificate
It seems the @jcolp is the knowledge person on TLS from development of Asterisk point of view, which is good since we are trying to understand what and how Asterisk supports TLS.