Re: VS: VS: [Sipping] FW: I-DACTION:draft-sawada-sipping-sip-offeranswer-01.txt (Comments 4 to 6)

[Paul Kyzivat <pkyzivat at cisco.com>]

Christer Holmberg (JO/LMF) wrote:

> > 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.)

	Paul

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