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Re: [Sipping] Summary of Closing the offer/answer rollback issue?
Gao
I am confused about your explanation.
Does "the suspending state" mean "preconditions are not met" ?
What does "part of the original modification" mean ?
signaling | O/A state (no precondition)
---------------------+----------------------------
init-INVITE/200/ACK | audio1
re-INVITE/183-rel | audio2
PRACK/200OK | audio2 +video1
UPDATE/200OK | audio3 +video1
UPDATE/200OK | audio3 +video2
UPDATE/200OK | audio4 +video2
UPDATE/200OK | audio4 +video3
UPDATE/200OK | audio5 +video3
UPDATE/200OK | audio6 +video4
Which is a part of the original modification ?
Which is new modification ?
Is the decision depend on preconditions ?
Regards,
Shinji
>Comments inline.
>
>
>> Subject: RE: [Sipping] Summary of Closing the offer/answer rollback issue?
>> Date: Mon, 2 Mar 2009 14:45:10 +0100
>> From: christer.holmberg at ericsson.com
>> To: gao.yang.seu at hotmail.com; gao.yang2 at zte.com.cn; shin at softfront.co.jp
>> CC: sipping at ietf.org; gonzalo.camarillo at ericsson.com
>>
>> Hi,
>>
>> As we know, sometimes when you use preconditions you may do some modifications for a
>> stream, in ADDITION to simply change the precondition status. I guess the most typical
>> example is codec refine, ie you reduce the sets of codecs when it's know what both
>> ends support.
>>
>> Wouldn't it be possible to say that whatever change is done for a stream, if the the
>> re-INVITE fails before the preconditions have been met everything will be rolled back
>> for that stream?
>
>
>
>[Gao] If all the Offer/Answer pairs during the suspending state are part of the original
>modification, it is.
>
>
>
>But if there is a new modification, it is not.
>
>
>>
>> So, if I send an UPDATE and remove a codec, while preconditions still haven't been met,
>> that codec change would also be rolled back if the re-INVITE fails.
>>
>>
>> SDP before re-INVITE audio-codec = 4
>>
>> ----- re-INVITE audio-codec = 1,2,3 precon = not_met --- >
>> <---- 18x audio-codec = 1,2,3 precon = not_met -----
>> ----- UPDATE audio-codec = 1 precon = not_met ----> //codec refine
>> <---- 200 audio-codec = 1 precon = not_met -----
>>
>> <---- 4xx --------------------------------------------------------------
>>
>>
>> SDP after re-INVITE audio-codec = 4
>>
>
>
>
>[Gao] If treat "refine codec" as part of the original modification, it is.
>
>
>
>
>>
>> Regards,
>>
>> Christer
>>
>>
>>
>>
>>
>> ________________________________
>>
>> From: gaoyang [mailto:gao.yang.seu at hotmail.com]
>> Sent: 2. maaliskuuta 2009 15:32
>> To: Christer Holmberg; gao.yang2 at zte.com.cn; shin at softfront.co.jp
>> Cc: sipping at ietf.org; Gonzalo Camarillo
>> Subject: RE: [Sipping] Summary of Closing the offer/answer rollback issue?
>>
>>
>> 1.
>> The question is same as asking whether "refine codec" is a new modification or just
>> part of the original modification.
>>
>> By RFCs, it is a new modification. But I can not stop other people to treat as part of
>> the original modification.
>>
>> If "refine codec" is a new modification by UPDATE/200OK, its commitment will go on and
>> without rollback.
>> If "refine codec" is part of the original modification, it will rollback for the
>> faillure the original modification.
>> Not matter by which point of view, the session state is all clear.
>>
>> 2.
>> I have no right to decide it("refine codec") alone.
>>
>> If people want to reach a consensus to this point, we can talk further.
>>
>> If ask my personal view, I can accept:
>> 2.1 treat it as new modification. or
>> 2.2 treat it as part of the original modification, but "protected" by precondition.
>>
>> Why "protected" by precondition?
>> By RFCs it is new modification at all, and as to make it part of the original
>> modification, we should have semantics of suspending/resuming modification.
>>
>> How "protected" by precondition?
>> We can define that only use "refine codec" in suspending state of QoS precondition.
>> IMO, it is better to define a new precondition type for "refine codec".
>>
>>
>> > Date: Mon, 2 Mar 2009 12:02:54 +0100
>> > From: christer.holmberg at ericsson.com
>> > To: gao.yang2 at zte.com.cn; shin at softfront.co.jp
>> > CC: sipping at ietf.org; gonzalo.camarillo at ericsson.com
>> > Subject: Re: [Sipping] Summary of Closing the offer/answer rollback issue?
>> >
>> >
>> > Hi,
>> >
>> >
>> > >Explanation for Precondition notification
>> > >
>> > >Precondition notification can be treated as part of the original modification
>> > >triggered by Re-INVITE.
>> > >
>> > >And only SDP with Precondition notification and without any other modification of
>> > >session, during suspending state of session
>> > >modification, is called precondition notification.
>> >
>> > So, what if I e.g. Also do a "codec refine" inside a precondition notficiation?
>> >
>> > Regards,
>> >
>> > Christer
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > >
>> >
>> > OKUMURA Shinji <shin at softfront.co.jp>
>> >
>> > 2009-03-02 17:43
>> >
>> >
>> > 收件人
>> > sipping <sipping at ietf.org>
>> > 抄送
>> > "Christer Holmberg" <christer.holmberg at ericsson.com>, gao.yang2 at zte.com.cn, Gonzalo
>> > Camarillo <gonzalo.camarillo at ericsson.com>
>> > 主题
>> > Re: [Sipping] Summary of Closing the offer/answer rollback issue?
>> >
>> >
>> >
>> >
>> >
>> >
>> > Hi,
>> >
>> > The following table describes my understanding.
>> > Is this right?
>> >
>> > signaling | O/A state | media in use
>> > ---------------------+--------------------------------+--------------
>> > init-INVITE/200/ACK | audio1(met) | audio1
>> > re-INVITE/183-rel | audio2(notmet) | audio1
>> > (PRACK/200OK) | audio2(met) +video1(notmet) | audio2
>> > UPDATE/200OK | audio2(met) +video1(met) | audio2+video1
>> > UPDATE/200OK | audio2(met) +video2(notm et) | audio2+video1
>> > 4xx/ACK | |
>> > Gonzalo's proposal | audio2 +video1 |
>> > Gao's proposal | audio1 +video1(?) |
>> >
>> >
>> > Regards,
>> > Shinji