Subject: [Sigtran] n+k redundancy + NTFY changes

From: [email-masked]
Date: Wed, 30 Jan 2002 05:43:29 -0800

Hi John,

Because I see that some -although minor- changes are discussed, I am
wondering whether there will be also a change to make n+k case to work in a
more reasonable way or are changes necessary for this too much for now?
Also closely related with this, will there be a text change for NTFY
expalining in detail when should it be sent and to which ASPs?

     Tolga

> -----Original Message-----
> From:   [email-masked]
> Sent:   Wednesday, January 30, 2002 6:21 AM
> To:     [email-masked]
> Cc:
> Subject:     [Sigtran] RE: M3UA-11 & SUA:  RK Management
>
>  Hi John,
> > In M3UA-11, sections 3.6 and 4.4 (and their parallel sections
> > in SUA), it is not clearly stated that the RK Management
> > Messages and Procedures are OPTIONAL.  This needs to be
> > clearly spelled out so that "new" readers will not think that
> > they have to do this stuff.
> >
> > I propose that "[OPTIONAL]" be added to the end of these
> > section titles.
> I do not have a problem with doing this - does anyone else have
> comments?
> John
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---

From: [email-masked]
Date: Thu, 31 Jan 2002 13:27:29 +0200

Hi Tolga,

First off, do you mean SUA or M3UA?

> wondering whether there will be also a change to make n+k 
> case to work in a more reasonable way or are changes necessary for this 
> too  much for now?

Can you be more specific about what you would like to see?

> expalining in detail when should it be sent and to which ASPs?

If you have text to suggest, it could be added.

John

---

From: [email-masked]
Date: Thu, 31 Jan 2002 10:11:21 -0800

Hi John L. ,

Those issues were first discussed on "M3UA-10 Example 5.1.4" thread. I
think they are applicable both for M3UA and SUA.

      Tolga

NTFY changes
===========
There the first problem mentioned was that in M3UA10-5.1.4 on the examples
NTFYs are not sent to all of the ASPs, where in "4.3.4.5 Notify Procedures"
it is said that NTFY should be sent to all of the ASPs in the AS, which are
not in DOWN state. Afterwards, this also brought the concerns, whether all
types of NTFY really should be sent to all ASPs in the AS, which are not in
DOWN state, or not. I think first of all it could be nice to explain, what
it means that "an ASP is in the AS". And also it should be enough to send
NTFY(Alternate ASP Active) only to  the previously active ASP.
My suggestion is : (applicable both for SUA and M3UA)
"4.3.4.5 Notify Procedures
A Notify message reflecting a change in the AS state MUST be sent to all
ASPs in the AS -ASPs, which are configured on SG to serve this AS in case
of static configuration and ASPs, which are registered on SG for this AS in
case of dynamic registeration-, except those in the ASP-DOWN state, with
appropriate Status Information and any ASP Identifier of the failed ASP. An
exception of this is that NTFY(Alternate ASP Active) messages should be
sent only to the ASP, which was previously ACTIVE for this AS. ........."

Also in "5. Examples of M3UA Procedures" in M3UA11 and "5. Examples of SUA
Procedures" in SUA11 on the examples where NTFY messages are sent, it
should be mentioned whether static or dynamic configuration is used, to be
able to decide, which ASPs are in the AS.
Another small comment about SUA, in "5.2. IPSP examples" is it possible to
include also examples about 2 ASP-UP case?

n+k redundancy
===============
Again this problem was first mentioned in M3UA10-5.1.4. thread but is
applicable for SUA as well. When ASPAC-ACK is received by an ASP, how can
it be sure that n ASPs are already active in case of n+k redundancy?
Because SGP won't start sending/receiving traffic till n ASPs are active
and so preferably ASP also shouldn't send traffic to SGP. This could be
done my making use of NTFY(AS Active). ASP should not start sending traffic
for an AS, unless it receives ASPAC-ACK and NTFY(AS active) for that AS.
Another problem case related with this is, if number of active ASPs fall
below n, how ASPs should behaeve. In this case SGP will stop sending
traffic and NTFY(Insufficient ASP resources active in AS) can be used by
active ASPs, to decide to stop traffic. Still their own ASP state will be
active, but they will wait till they receive a  NTFY(As active) (a new ASP
will become active and active ASP number will reach n so that SGP will send
this NTFY). If we want n+k redundancy configuration, I think we should move
to this direction. Another alternative is of course getting rid of n+k
redundancy.

> Sent:   Thursday, January 31, 2002 12:53 PM
> To:     [email-masked];[email-masked]
> Cc:
> Subject:     RE: [Sigtran] n+k redundancy + NTFY  changes
>
>  Hi Tolga,