Re: [Sigtran] M3UA: Synchronizing DPC availability state between ASPs in the same AS

"Brian F. G. Bidulock" <bidulock@openss7.com> Mon, 10 April 2017 20:09 UTC

Date: Mon, 10 Apr 2017 14:09:32 -0600
From: "Brian F. G. Bidulock" <bidulock@openss7.com>
To: Dan Gora <dan.gora@gmail.com>
Cc: bidulock@openss7.com, sigtran@ietf.org
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Subject: Re: [Sigtran] M3UA: Synchronizing DPC availability state between ASPs in the same AS
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Dan,

Please see comments below...

Dan Gora wrote:                    (Mon, 10 Apr 2017 17:00:12)
> 
> If we have to "fix" this, it seems like it should be safe to
> synchronize the states across all the active ASPs.  I cannot think of
> a scenario where a DPC would be available in ASP 1 via SG1, but not
> via ASP2 as long as both are connected and ASP-Active with the SG1
> since the SG1 has to synchronize it's state among all the SGPs in the
> SG.  Right?

Well, no.  We considered that an SG with multiple SGP might get
one or more SGPs partitioned from the others, and potentially
isolated from the network.  Although they are isolated, their
M3UA connections to the ASPs in the AS are still viable and
the unsolicited ASP Inactive Ack procedure might not be
necessary.  In that case, some SGP might send DUNA(*) while the
others still have available routes.  This was a major reason
for sending periodic DAUD to the SGP that sent the corresponding
DUNA, DRST, SCON.

-- 
Brian F. G. Bidulock
bidulock@openss7.com
http://www.openss7.com/

[Sigtran] M3UA: Synchronizing DPC availability st… Dan Gora
Re: [Sigtran] M3UA: Synchronizing DPC availabilit… David Laight
Re: [Sigtran] M3UA: Synchronizing DPC availabilit… Brian F. G. Bidulock
Re: [Sigtran] M3UA: Synchronizing DPC availabilit… Brian F. G. Bidulock
Re: [Sigtran] M3UA: Synchronizing DPC availabilit… Dan Gora
Re: [Sigtran] M3UA: Synchronizing DPC availabilit… Brian F. G. Bidulock
Re: [Sigtran] M3UA: Synchronizing DPC availabilit… Dan Gora