| "Christer Holmberg"
<christer.holmberg@xxxxxxxxxxxx>
2009-04-07 18:36 |
|
Hi,
>I mean rejectable in app-level. 491 is beneath app-level.
>And precondition notification is not a rejectable usage in app-level.
Ok, so where is all that defined?
[Gao] By RFC3312: The offerer generates a transaction
status table, identical to its local status table, and sends it to
the answerer in the offer. The answerer uses the information of this
transaction status table to update its local status table. The
answerer also updates the transaction status table fields that were
out of date and returns this table to the offerer in the answer. The
offerer can then update its local status table with the information
received in the answer. After this offer/answer exchange, the local
status tables of both user agents are synchronised.
The precondition state is just notification/updating, not negotiating.
>BTW, I saw some points of view (just today and yesterday) which want to make it simple.
I also want to make it simple.
Saying that something must never happen is a very simple solution. We sould do that for other things also, and our specs would become very short... :)
[Gao] I am not sure we are talking the same thing :)
I mean that some people do not want modification here.
Regards,
Christer
Hi,
>>I think we already a while ago agreed on the principle that it shall be possible to send a non-200 response to a PRACK (not only for offer/answer, but possibly also due to other reasons).
>
>[Gao] Then, it is a modification of RFC3262.
Yes.
>And, in that case, why would an intermeidate be allowed to reject a PRACK, but not the UAS?
>
>[Gao] I think, by RFC3262, it is not suitable to put too much usage in the PRACK to make it rejectable.
Every request is rejectable, no matter how much or little usage you have in it.
Regards,
Christer
From: sipping-bounces@xxxxxxxx [mailto:sipping-bounces@xxxxxxxx] On Behalf Of gao.yang2@xxxxxxxxxx
Sent: Tuesday, April 07, 2009 4:33 AM
To: Paul Kyzivat
Cc: sipping-bounces@xxxxxxxx; sipping@xxxxxxxx; Christer Holmberg
Subject: [Sipping] 答复: Re: PRACK: Change MUST requirement to include SDP offer in first reliable provisional response
More points of view to this question:
By RFC3262:
1. "Retransmissions of the reliable provisional response cease when a matching PRACK is received by the UA core."
2. "If the PRACK does match an unacknowledged reliable provisional response, it MUST be responded to
with a 2xx response."
So, when UAs receive a matching PRACK, it will stop re-transmit the reliable provisional response(18x). And the response
to PRACK MUST be 2xx.
It is simple and clear. And when UAs receive non-2xx response to PRACK, it is clear that the other side do not receive the
PRACK. It can send a new PRACK(CSeq++, the same RAck).
And now, we can use PRACK to send "precondition notification" and "codec refine". When we need to issue session modification like adding codec,
adding/removing media streams, we MUST using Re-INVITE/UPDATE.
I think we should not re-write RFC3262 to allow the UA to reject the PRACK.
| Paul Kyzivat <pkyzivat@xxxxxxxxx>
发件人: sipping-bounces@xxxxxxxx 2009-04-06 20:16 |
|
I think I also agree. There are a lot of things that in hindsight we
probably would have done differently. But that is water over the dam. We
are where we are.
Paul
Rockson Li (zhengyli) wrote:
> I totally agree with Hadriel's insight here.
>
> It should have been avoided to put too many jobs into PRACK,
>
> I miss KISS(Keep It Simple and Stupid) principle
>
>
>
> Regards,
>
> -Rockson
>
> ------------------------------------------------------------------------
> *From:* sipping-bounces@xxxxxxxx [mailto:sipping-bounces@xxxxxxxx] *On
> Behalf Of *Hadriel Kaplan
> *Sent:* Tuesday, March 31, 2009 9:50 PM
> *To:* Christer Holmberg; sipping@xxxxxxxx
> *Subject:* Re: [Sipping] PRACK: Change MUST requirement to include SDP
> offer in first reliable provisional response
>
>
>
>
>
> In hindsight I’m thinking we probably also shouldn’t have made the SDP
> answer (or another offer) required or even possible in the PRACK
> either. I think it should have been for one and only one purpose: to
> acknowledge receipt of the provisional response.
>
>
>
> -hadriel
>
>
>
>
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Sipping mailing list https://www.ietf.org/mailman/listinfo/sipping
> This list is for NEW development of the application of SIP
> Use sip-implementors@xxxxxxxxxxxxxxx for questions on current sip
> Use sip@xxxxxxxx for new developments of core SIP
_______________________________________________
Sipping mailing list https://www.ietf.org/mailman/listinfo/sipping
This list is for NEW development of the application of SIP
Use sip-implementors@xxxxxxxxxxxxxxx for questions on current sip
Use sip@xxxxxxxx for new developments of core SIP
--------------------------------------------------------
ZTE Information Security Notice: The information contained in this mail is solely property of the sender's organization. This mail communication is confidential. Recipients named above are obligated to maintain secrecy and are not permitted to disclose the contents of this communication to others.
This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the originator of the message. Any views expressed in this message are those of the individual sender.
This message has been scanned for viruses and Spam by ZTE Anti-Spam system.
--------------------------------------------------------
ZTE Information Security Notice: The information contained in this mail is solely property of the sender's organization. This mail communication is confidential. Recipients named above are obligated to maintain secrecy and are not permitted to disclose the contents of this communication to others.
This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the originator of the message. Any views expressed in this message are those of the individual sender.
This message has been scanned for viruses and Spam by ZTE Anti-Spam system.
--------------------------------------------------------
ZTE Information Security Notice: The information contained in this mail is solely property of the sender's organization. This mail communication is confidential. Recipients named above are obligated to maintain secrecy and are not permitted to disclose the contents of this communication to others.
This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the originator of the message. Any views expressed in this message are those of the individual sender.
This message has been scanned for viruses and Spam by ZTE Anti-Spam system.
-------------------------------------------------------- ZTE Information Security Notice: The information contained in this mail is solely property of the sender's organization. This mail communication is confidential. Recipients named above are obligated to maintain secrecy and are not permitted to disclose the contents of this communication to others. This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the originator of the message. Any views expressed in this message are those of the individual sender. This message has been scanned for viruses and Spam by ZTE Anti-Spam system.
_______________________________________________ Sipping mailing list https://www.ietf.org/mailman/listinfo/sipping This list is for NEW development of the application of SIP Use sip-implementors@xxxxxxxxxxxxxxx for questions on current sip Use sip@xxxxxxxx for new developments of core SIP
