Re: [Sipping] Summary of Closing the offer/answer rollback issue?

["Christer Holmberg" <christer.holmberg at ericsson.com>]

Hi, 

>>I think the one of the main issues at the moment is what happens after

>>preconditions have been met on both sides:
>>
>>1) Is the change now commited/in-use, and a re-INVITE failure would
not
>>change that?                                       <----- "in-use"
alternative
>>OR
>>2) Would a re-INVITE failure cause a fallback (this is what is meant
by
>>"late commitment")?                                <---- "late
commitment" alternative
> 
>Ahh.  Well if that's the issue, I vote for doing exactly 
>whatever would happen if a normal (non-pre-conditional) SDP 
>offer/answer is exchanged and the re-INVITE fails.  I have 
>absolutely no idea what that would be, but it should be the 
>same. :) (I mean I know what 3261 says, that it reverts all 
>the way back, but I have no idea if that's actually what most 
>people do)

Sure, the issue is valid also for non pre-condition use-cases.

For example.

The UAC sends an SDP offer in a re-INVITE, and receives an SDP answer in
a reliable 18x. But, then what happens when the re-INVITE fails?

1) Is the change now commited/in-use, and a re-INVITE failure would not
change that?                                       <----- "in-use"
alternative

OR

2) Would a re-INVITE failure cause a fallback (this is what is meant by
"late commitment")?                                <---- "late
commitment" alternative

>If I had my druthers the SDP change would stick (not revert), 
>because I personally think it's cleaner, but I can see an 
>argument for both ways.

Yes.

Regards,

Christer