We need to take care of cases, when one leg has pending
transaction(s), and an opposite leg triggers media re-negotiations,
which assumes we have to update the first leg as well (the one which
has a pending transaction).
Perviously we used to only support sending a fake 200OK to the one,
who triggered a media attributes re-negotiation, and scheduling
an update for the opposite leg for a later time (as soon as its done
with its own transaction(s) ).
For now we can optionally decide whether:
- to send 200OK to the one who triggers re-INVITE
- to send 491 Pending to the one who triggers re-INVITE
Using the approach with 491, gives a solution to the problem,
when a fake 200OK is sent to the remote side, and ACK after a while
is not matched to any of the existing local transactions.
This can happen in case, we have sent a fake 200OK, but SBC triggers
one more transaction towards the same side (over already existing one).
This behavior leads to a failure when trying to match coming ACK to the fake 200OK.
By default, enabled behavior - generate fake 200OK.
Optionally it's now possible to enable 491 Pending response,
by setting sems.conf option:
- send_491_on_pending_session_leg = 'yes'
Change-Id: I17f41833651eb006666315c1f9a7cfd4c0441f8a
Donat Zenichev
cb48c879b7