| Newsgroups |
gmane.ietf.sigtran |
| Message-ID |
<[email protected]> |
Tolga,
Well let me express in detail:
"A combined view of the AS is maintained across all SGPs serving that
AS. This means the state of AS would be maintained at SG. The sate of
ASPs serving the (above) AS should be coordinated/shared across all SGPs
serving the AS. Shared should not be taken as maintained. What I mean is
the SGPs are just aware of the state of a particular ASP at a particular
SGP in an AS. Only then they can have a combined view of AS"
Now, if you don't agree with the above, let's consider the redundancy
model n+k for AS. Here for simplicity I consider the value of n=2 and
k=0. Guess you would agree that as per this model the AS would be
considered active only when the number of active ASPs is 2.
Let's also consider 2 ASPs (ASP1 and ASP2) and two SGPs (SGP1 and SGP2)
for the above model.
ASP1 ------------- SGP1 (sctp association established and ASP1 inactive)
ASP2 ------------- SGP2 (sctp association established and ASP2 inactive)
Now if we take your view into consideration, then even if the ASPs
become active at there respective SGPs (i.e. ASP1 at SGP1 and ASP2 at
SGP2), the AS will still not be active. Why? For your view the ASPs
states would not be shared across SGPs serving a common AS! And the
minimum required ASPs are 2 for AS to become active!! Do you think,
that's okay?? Isn't the redundancy model n+k takes the overall view of
AS at SG to support failover? I guess with your view into consideration,
the interoperability would be broken here as the AS would never become
active.
Alternatively, let's change the values. N=2 (still!) and K=1 and
introduce another ASP3 having association with SGP2 but currently
inactive. Now if SGP1 fails or ASP1 goes down, who do think would notify
to ASP3 of insufficient ASPs?(assuming ASPs in AS are not able to share
state information). Only SGP2 can do it and without the knowledge of the
combined AS view, can it?? And combined AS view at SGP2 can only be
arrived at with the ASP state sharing!!
Brian, your views?
Regards,
Prabind
-----Original Message-----
From: Tolga Asveren [mailto:[email protected]]
Sent: Thursday, February 23, 2006 6:47 PM
To: [email protected]
Subject: RE: [Sigtran] M3UA notify message
Prabind,
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> Sent: Wednesday, February 22, 2006 11:20 PM
> To: [email protected]
> Subject: RE: [Sigtran] M3UA notify message
>
>
>
> I am still concerned about this statement from Tolga:
>
> " In any case, it is good that there is finally consensus regarding
that
> ASPSM/ASPTM procedures and associated state machines being independent
> on
> each SGP."
>
> If multiple SGPs are serving a single AS, then shouldn't the ASP
states
> also be shared across the related SGPs?
> Else if I am wrong then the following statement in section 1.4.1
should
> be amended to share the AS states only.
> " Where an SG contains more than one SGP, the MTP3 routeset, SPMC and
> remote AS/ASP states of each SGP SHOULD be coordinated across all
the
> SGPs."
>
> Tolga, further considering the sahring of ASP states then, in the case
> of the interoperability issue (as you depicted), the rfc says that if
an
> ASP is already inactive the ASP-UP message would still be respnded by
an
> ack.
[TOLGA]So are you claiming that there won't be an interoperability issue
according to the message flow I sent? Please look to steps marked with
(1)
and (2). If one uses a global AS/ASP state which is SG-wide for
ASPSM/ASPTM
procedures, interoperability issues will arise. OTOH, with NTFY, there
is no
such danger, afterall it is just advisory.
>
> I think the things become simpler if we consider sharing of ASP states
> of a particular AS across all SGPs serving that AS.
>
>
> Regards,
>
> Prabind
>
>
> -----Original Message-----
> From: Tolga Asveren [mailto:[email protected]]
> Sent: Thursday, February 23, 2006 6:53 AM
> To: [email protected]
> Subject: RE: [Sigtran] M3UA notify message
>
> Brian,
>
> As long as it is not an ASPSM/ASPTM procedure, it is fine. I probably
> was
> not careful when using the term "M3UA procedures" because it includes
> pretty
> much everything.
>
> BTW, I still wouldn't call it "M3UA procedure on each SGP", because
SSNM
> is
> not sent independently by each SGP when status of a destination in SS7
> network changes. It is supposed to be sent only once, but this is
> besides
> the point for this thread.
>
> In any case, it is good that there is finally consensus regarding that
> ASPSM/ASPTM procedures and associated state machines being independent
> on
> each SGP.
>
> Tolga
>
> > -----Original Message-----
> > From: Brian F. G. Bidulock [mailto:[email protected]]
> > Sent: Wednesday, February 22, 2006 8:34 PM
> > To: Tolga Asveren
> > Cc: [email protected]
> > Subject: Re: [Sigtran] M3UA notify message
> >
> >
> > Tolga,
> >
> > By an SGP, making it an "M3UA procedure on each SGP".
> >
> > --brian
> >
> > Tolga Asveren wrote:
> > (Wed, 22 Feb 2006 18:10:02)
> > > Yes, SSNM will be sent per SG.
> > >
> > > BTW, my messages from a few hours ago started just to arrive, not
in
> the
> > > order I sent them.
> > >
> > > Tolga
> > >
> > > > -----Original Message-----
> > > > From: Brian F. G. Bidulock [mailto:[email protected]]
> > > > Sent: Wednesday, February 22, 2006 6:26 PM
> > > > To: Tolga Asveren
> > > > Cc: [email protected]
> > > > Subject: Re: [Sigtran] M3UA notify message
> > > >
> > > >
> > > > Tolga,
> > > >
> > > > BTW it is used for sending SNMM from an SGP: another M3UA
> > > > procedure at an SGP.
> > > >
> > > > --brian
> > > >
> > > > Tolga Asveren wrote:
> > > > (Wed, 22 Feb 2006 15:36:22)
> > > > > Brian,
> > > > >
> > > > > Please show where in the specification it says that
ASPTM/ASPSM
> > > > relationship
> > > > > is between ASP and SG?
> > > > >
> > > > > Thanks,
> > > > > Tolga
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Brian F. G. Bidulock [mailto:[email protected]]
> > > > > > Sent: Wednesday, February 22, 2006 3:50 PM
> > > > > > To: Tolga Asveren
> > > > > > Cc: [email protected]
> > > > > > Subject: Re: [Sigtran] M3UA notify message
> > > > > >
> > > > > >
> > > > > > Tolga,
> > > > > >
> > > > > > Tolga Asveren wrote:
> > > > > > (Wed, 22 Feb 2006 15:28:21)
> > > > > > > Barry,
> > > > > > >
> > > > > > > Let me retry to explain my position:
> > > > > > >
> > > > > > > Coordination of AS/ASP is necessary to create the unique
> > > > SPMC view. This
> > > > > > > does not mean that the coordinated state should be used
for
> > > > > > M3UA procedures
> > > > > > > on each SGP. Each SGP should maintain its own staet
machine
> > > > from ASP/SGP
> > > > > > > procedures point of view.
> > > > > > >
> > > > > >
> > > > > > Your statements conflict with the consensus that went into
> > > > > > the RFC as upheld by the mailing list discussion on the
> matter.
> > > > > >
> > > > > > --brian
> > > > > >
> > > > > > --
> > > > > > Brian F. G. Bidulock
> > > > > > [email protected]
> > > > > > http://www.openss7.org/
> > > > > >
> > > > > > _______________________________________________
> > > > > > Sigtran mailing list
> > > > > > [email protected]
> > > > > > https://www1.ietf.org/mailman/listinfo/sigtran
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > > _______________________________________________
> > > > > Sigtran mailing list
> > > > > [email protected]
> > > > > https://www1.ietf.org/mailman/listinfo/sigtran
> > > >
> > > > --
> > > > Brian F. G. Bidulock
> > > > [email protected]
> > > > http://www.openss7.org/
> > > >
> > >
> > >
> > >
> > > _______________________________________________
> > > Sigtran mailing list
> > > [email protected]
> > > https://www1.ietf.org/mailman/listinfo/sigtran
> >
> > --
> > Brian F. G. Bidulock
> > [email protected]
> > http://www.openss7.org/
> >
>
>
>
> _______________________________________________
> Sigtran mailing list
> [email protected]
> https://www1.ietf.org/mailman/listinfo/sigtran
>
> _______________________________________________
> Sigtran mailing list
> [email protected]
> https://www1.ietf.org/mailman/listinfo/sigtran
>
_______________________________________________
Sigtran mailing list
[email protected]
https://www1.ietf.org/mailman/listinfo/sigtran