Hi,
Precisely which scenarios do you mean. It is pretty crazy to expect
such behavior, but I am not too surprised if there are scenarios like
that.
I think there are a cases that require a UAS to be psychic. (Those
related to REFER often feel that way. Dale has recently written
something on that.)
[CHH] It's quite a while since we discussed this, but hopefully those
who pushed for the specfic behavior can correct me if I'm wrong. The
scenario was something like the following:
User A receives an hold re-INVITE. Later (when some transfer functions
have taken place) user A receives an empty re-INVITE. Now, in order to
make things work, user A is supposed to un-hold the session and send
an SDP offer as for a new session - not simply return the SDP from the
previous offer/answer transaction.
This doesn't require User A to be psychic - only to keep stating its
desires at each opportunity.
In this scenario I believe User A was *put on hold* - he didn't *want*
to be on hold. So at each opportunity (like the offerless reinvite) it
simply
states what it wants - which is *not* to be on hold.
If, after A had been put on hold it decided to initiate its own hold
action (perhaps because another call was received), then when the
reinvite is
received it might indeed specify SENDONLY. That wouldn't be what the
sender of the reinvite wants to hear, but it is the current situation.
(Of course
when A decided to do it own hold it probably should have done its own
reinvite specifying INACTIVE.)
Ok, so what is the "desire" of an MGC (or any other entity without
direct user control)? How does an MGC know whether he "wants" to be on
hold or not?