I notice that
Asterisk needs to be patched to do it the way Kamailio does:
https://issues.asterisk.org/jira/browse/ASTERISK-17727
The Asterisk TCP/TLS implementation is marked experimental for a reason. And it's
been that way for many years.
All the more reason for people to use a product like Kamailio as the
`hub' of their SIP network, and keep Asterisk as a service hanging off
the side