Ideally I think Kamailio should send correct (i.e increasing) CSeq numbers.
in my mind it can't be increased by kamailio because of:
1. kamailio send OPTIONS with cseq+1
2. media server may send some indialog reinvite with cseq+1 and then kamailio have to remember that OPTIONS and translate reinvite to cseq+2.
Fair point, statelessness is important.
I don't know why for "ka-src" CSeq is 0 and for "ka-dst" the one is equal: so may be it is possible to be fixed
I'll investigate, under the assumption everyone agrees it's a bug.
(for example BYE) to be dropped by the firewall.
this may be achieved by
1. usrloc pinging
I'm not sure that is usrloc pinging, but if you mean nathelper's nat_ping, then that wouldn't work for me because it's only for MUAs that use REGISTER, which on my system does not always happen.
2. short re-registration period for endpoint (60 sec for ex)
Aside from the fact that REGISTER is not guaranteed to ever happen, this is also a UA setting that can't be enforced by the server and has serious implications on battery life outside of a call.
3. let's media server send options by itself via kamailio
This may or may not be possible on my setup, I'll have to investigate - thanks for the suggestion!
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