It should not change during the call. The rules prohibit that. The only way to change the
remote target address within a dialog is, ironically, via a reinvite and/or response, but
that would need to come from the UA itself.
Your best bet to ensure that the NAT pinhole to the endpoint does not go away during the
call is some sort of keepalive, be it the NAT "ping" functionality of the
nathelper module or the in-dialog OPTIONS pings from the dialog module. That should keep
the NAT mapping refreshed.
If the endpoint still becomes unreachable, there's not much you can do. Nothing that
would conform to the protocol state machine, anyway. :-)
--
Alex Balashov | Principal | Evariste Systems LLC
303 Perimeter Center North, Suite 300
Atlanta, GA 30346
United States
Tel: +1-800-250-5920 (toll-free) / +1-678-954-0671 (direct)
Web:
http://www.evaristesys.com/,
http://www.csrpswitch.com/
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