Subject: [Sip] A thread about problem of SIP event framework

From: Xiao Wang <[email-masked]>
Date: Mon, 20 Feb 2006 16:35:04 +0800

Hi, all

         As we all know that SIP event framework RFC3265 define one method
(SUBSCRIBE) to implement two functions,

One is initial subscription, another is refresh subscription. According to
RFC3265, the refresh SUBSCRIBE request not only

refresh subscription, but also get a full state of last resource in NOTIFY
request. It is overloaded to refresh SUBSCRIBE request,

in some cases, the functions of refresh subscription and get resource full
state must not provided together. User can choose to refresh

subscription alone or get full state of last resource alone.

         The draft "draft-niemi-sip-subnot-etags-00" try to solve this
problem, but it did not completely solve, it only restrain to contain the
full state in NOTIFY that refresh SUBSCRIBE request make, but NOTIFY request
is always sent after refresh SUBSCRIBE request.

         There have been a few threads about it. I will start a thread here.

         Define a parameter in Event header field, called "nonotify", like
this   

Event: presence; nonotify

         If subscriber did not want to get full state of last resource ,
then include "nonotify" in the Event header field of refresh SUBSCRIBE
request, otherwise did not include.

        The notifier received refresh SUBSCRIBE request, check Event header
field, if notifier supported  "nonotify" parameter, then it did not send
NOTIFY, otherwise according to RFC3265 to do.

Xiao

_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [email-masked] for questions on current sip
Use [email-masked] for new developments on the application of sip

---

From: Avshalom Houri <[email-masked]>
Date: Mon, 20 Feb 2006 12:16:01 +0200

Xiao,

I raised the issue several times in the simple list and in the 
sip-implementors list and got very small attention.
The direction that you suggest seems as a good approach. I think that not 
sending the NOTIFY for
SUBSCRIBE refreshes should have been the default behaviour in RFC 3265 but 
now your suggestion seem
good to me.

Thanks
Avshalom

Xiao Wang <[email-masked]> 
20-02-06 10:35 AM

To
[email-masked]
cc

Subject
[Sip] A thread about problem of SIP event framework

Hi, all

         The draft "draft-niemi-sip-subnot-etags-00" try to solve this
problem, but it did not completely solve, it only restrain to contain the
full state in NOTIFY that refresh SUBSCRIBE request make, but NOTIFY 
request
is always sent after refresh SUBSCRIBE request.

         There have been a few threads about it. I will start a thread 
here.

        The notifier received refresh SUBSCRIBE request, check Event 
header
field, if notifier supported  "nonotify" parameter, then it did not send
NOTIFY, otherwise according to RFC3265 to do.

Xiao

---

From: Xiao Wang <[email-masked]>
Date: Mon, 20 Feb 2006 20:08:27 +0800

Avshalom,
  Thanks. I think that this problem is although inappreciable, but in fact
take a trouble for developers
in some scenario. Because there have many implementations according to
RFC3265, so we had better find a good
way to have least modify to implementations. 
  Folks, if have some new ideas?

Xiao
________________________________________
From: Avshalom Houri [mailto:[email-masked]] 
Sent: Monday, February 20, 2006 6:16 PM
To: Xiao Wang
Cc: [email-masked]
Subject: Re: [Sip] A thread about problem of SIP event framework

Xiao, 

Thanks 
Avshalom

Subject

Hi, all

Xiao

---

From: Aki Niemi <[email-masked]>
Date: Mon, 20 Feb 2006 14:49:38 +0200

> is always sent after refresh SUBSCRIBE request.

As I mentioned in some other thread, what's described in the draft is, 
in the scale of conservative-to-hackish, clearly on the conservative 
end. The draft also discusses the reasons for the choice.

If consensus determines it is OK to break some of the RFC 3265 rules, 
then subnot-etags could simply be defined to always suppress the NOTIFY 
instead and, say, return a new 2xx response to the SUBSCRIBE for when 
the refresh succeeds, expiry is extended, but NOTIFY is suppressed.

I still don't think following HTTP's and SIP PUBLISH's model and 
returning a 412 will work.

> Event: presence; nonotify

Sure, but I still prefer the subnot-etags mechanism, since this doesn't 
work with polls or fetches. And I'd like whatever mechanism we define to 
work for both cases.

Cheers,
Aki

---

From: Xiao Wang <[email-masked]>
Date: Mon, 20 Feb 2006 21:05:07 +0800

Aki,
   Your thread is right. But I want to make it more simple to solve this
problem,
and I prefer to split the SUBSCRIBE method to two single functions. If only
suppress NOTIFY to be sent, subnot-etags wastes it's talent on a petty job.
I think that subnot-etags must have more sufficient reason to use. Thanks. 

Xiao
> -----Original Message-----
> From: Aki Niemi [mailto:[email-masked]]
> Sent: Monday, February 20, 2006 8:50 PM
> To: ext Xiao Wang
> Cc: [email-masked]
request
here.