[SR-Users] Q: purpose of t_newtran() in kamailio-basic.cfg route[LOCATION]?

In kamailio-basic.cfg route[LOCATION] we have the following:

--snip-- $var(rc) = $rc; t_newtran(); switch ($var(rc)) { case -1: case -3: --snip--

What is the purpose of t_newtran() here? Since we have not hit t_relay() yet (and don't have a transaction) is this to ensure the caller sees/acks the 404/405?

Earlier in the mailing list https://lists.kamailio.org/pipermail/sr-users/2015-April/088062.html I read, although this is in reply to a different situation:

"Why do you need to create new transactions yourself with t_newtran()? Nonexotic applications of Kamailio usually don't require this. ..."

# User location service route[LOCATION] { if (!lookup("location")) { $var(rc) = $rc; t_newtran(); switch ($var(rc)) { case -1: case -3: send_reply("404", "Not Found"); exit; case -2: send_reply("405", "Method Not Allowed"); exit; } }

# when routing via usrloc, log the missed calls also if (is_method("INVITE")) { setflag(FLT_ACCMISSED); }

route(RELAY); exit; }

Thanks AAlba