enable_tls=1
tcp_async=no # do not include in 3.1
listen=udp:0.0.0.0:5060
listen=tcp:0.0.0.0:5060
^^^^^^^^ it should not be 0.0.0.0 but an
actual IP.
If you use 0.0.0.0 you _must_ set adevertised_adress or
you will have some strange Vias && RRs.
listen=tls:0.0.0.0:5061 # not needed in 3.1
^^^^^^^^^^^^^^^^ - it's optional only if you have another
listen which does not specify the protocol
(e.g. listen=10.0.0.2:5060 or
listen=10.0.0.2). In this case ser will
listen on all protocols on the default
port). I
This is true also for 3.0 and at least for
all ser versions.