[SR-Users] tm problem with two copies of the same invite

[Juha Heinanen]

there is a broken grandstream sip ua that sometimes sends two initial
invites back-to-back.  according to wireshark, sr received them about 10
microseconds apart.  sr then forwards the request to pstn gw, but i
don't have wireshark dump of that side of the traffic.  anyway, from the
ua side i see that about 10 milliseconds after receiving the invites, sr
replies to the ua "503 no more gateways available".

in my config that reply comes only from GW_FAILURE failure route,
which is set up like this:

t_on_failure("GW_FAILURE");
t_set_fr("120000", "5000");
t_relay()

so no way should failure route get executed before 5 seconds, but in
this back-to-back invite case it somehow gets executed almost
immediately.  i have not seen this behavior in other situation.

this looks like a bug to me.  perhaps there is some race condition
causing it?  version of sr where this appears is 3.0.3.

-- juha