Subject: RE: [Sigtran] m3ua: IG : n+k redundancy

From: "Javier Pastor-Balbas (ECE)" <[email-masked]>
Date: Fri, 21 Jun 2002 18:17:50 +0200

Hi Tolga, 

The conclusion I got from the mails is:

	- You proposed a diagram for AS
	- And also text changes to consider n as required
	- But some folks preferred the text as it is now leaving the MAY

Then I didn't find consensus for the change. At the end of the discussion both parts (mainly Brian and you) had an opposite vision. Then I would consider that no text change is included.

From my point of view the inclusion of the new AS diagram and leaving the text as it is today would be an improvement regarding clarity but leaving the options open. Anyone against this?

Cheers // Javier.

> -----Original Message-----
> From: Tolga Asveren [mailto:[email-masked]]
> Sent: Friday, June 21, 2002 6:09 PM
> To: [email-masked]
> Subject: [Sigtran] m3ua: IG : n+k redundancy
> 
> 
> Javier,
> 
> Could you also summarize the latest situation about n+k redundancy.
> 
>   Tolga 
>  
> 
> _______________________________________________
> Sigtran mailing list
> [email-masked]
> https://www1.ietf.org/mailman/listinfo/sigtran
> 

_______________________________________________
Sigtran mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/sigtran

---

From: "Brian F. G. Bidulock" <[email-masked]>
Date: Fri, 21 Jun 2002 11:52:09 -0500

Javier,

Javier Pastor-Balbas (ECE) wrote:                          (Fri, 21 Jun 2002 18:17:50)
> Then I didn't find consensus for the change. At the end of the discussion
> both parts (mainly Brian and you) had an opposite vision. Then I would
> consider that no text change is included.

Well, let's build concesus: does anyone have a problem with this change?

--brian

-- 
Brian F. G. Bidulock
[email-masked]
http://www.openss7.org/

---

From: "Tolga Asveren" <[email-masked]>
Date: Fri, 21 Jun 2002 14:07:32 -0400

Brian,

> From: Brian F. G. Bidulock [mailto:[email-masked]]
> Sent: Friday, June 21, 2002 12:52 PM
> To: Javier Pastor-Balbas (ECE)
> Cc: 'Tolga Asveren'; [email-masked]
> Subject: Re: [Sigtran] m3ua: IG : n+k redundancy
>
>
> Javier,
>
[TOLGA] I have a problem for the reasons I explained in the corresponding
thread. MAY possibly will create problems if ASP and SGP interprete MAY in
the opposite way.

---

From: "Tolga Asveren" <[email-masked]>
Date: Mon, 24 Jun 2002 09:55:01 -0400

Let me explain in a little bit more in detail about possible changes for n+k
redundancy:

The original method of activating AS with one ASP active and sending
NTFY("Insuff. ASP Act") if more active ASPs are desireable is fine. But in
such a case, that "SGP MAY choose not to direct traffic" is not the correct
behavior, because AS is active with the first active ASP, traffic shouldn't
be withhold afterwards. I am not against this mode of operation, might be
usefull for some cases.

But it is also clear that the above method lacks the ability to wait for n
ASPs to be active, before statrting to send/receive traffic for this AS. In
such a case, AS will switch to active state only after n ASPs are active.
Again there is no need for the sentence "SGP MAY choose not to direct
traffic" because, it shouldn't start traffic before AS is active.

Similar comments apply also for the sentence "ASPs should coordinate number
of active ASPs among themselves". This is not necessary for case1 -but still
not wrong- but is necessary for case2. In fact even for case2, it might be
added that SGP shouldn't send DATA before sending NTFY("AS Active") but this
would be a diversion from the approach that NTFY is only advisory (and also
DATA and NTFY are sent on separate streams, which might cause loss of
sequence between them)

Another small open point for case2 is, whether "n" should be a part of the
traffic mode or not (for example when traffic mode is present in ASPAC
message). I tend to think that this would be nice (by adding an optional
subparameter) but also I am not sure whether this could be considered as a
too big change for this moment.

   Tolga