Hi,

for a start - did you already tried this parameter:http://www.kamailio.org/wiki/cookbooks/5.5.x/core#tcp_reuse_port

Then have a look for example to this discussion:https://lists.kamailio.org/pipermail/sr-users/2019-November/107222.html

Thanks for the pointers. Got it to work.

For the record, what I did:

* add "name sock_tls" to the listen= parameter

* set tcp_reuse_port=yes

* the handler for OPTIONS saves the remote port to $shv(port__XXX)

* my call handler sets $fsn="sock_tls" and $rp to $shv(port__XXX)

… and that's it. So that was easier than expected.

NB, when browsing the sources for this I noticed that the "tcp_reuse_port" option is not recognized at all if the OS does not support SO_REUSEPORT.

However, here we're re-using an existing connection instead of opening a new connection from a port that has existing connections. Thus on systems that don't have SO_REUSEPORT (some BSDs, AFAIK) this method doesn't work (but should).

This mismatch is also the reason why I didn't notice this option in the documentation …