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

["Brian F. G. Bidulock" <[e-mail]>]

Dan,

When an SG sends DUNA, DAVA, DRST, SCON for an AS, we had
long discussions and agreed that it was sufficient that the
SG sends the indication to at least one ASP active for the
AS with the SG.  Even so, many SG vendors send the indication
to _every_ ASP active for the AS.  Multiple M3UA associations
between SG and AS can be viewed as links in a linkset, and,
following the analogy, an STP will only send TFP, TFA, etc.
on one link in the linkset.

However, this was never really the case for DAUD.  DAUD is
sent from ASP to SGP not from AS to SG.  For periodic DAUD,
the recommendation is that the DAUD be sent from an ASP to
the SGP that send the corresponding DUNA, DAVA, DRST, SCON.

For MTP Restart procedure, the recommendation was that the
SGP send DUNA, DAVA, DRST, SCON after receiving the ASP
Active and before sending the ASP Active Ack, so that the
ASP will not send traffic to unavailable destinations when
it becomes active.

So, yes and no, you may have to correlate the receipt of
DUNA, DAVA, DRST, SCON at any ASP across all ASPs active
for the AS (if the SG does not broadcast); however, you
should never have to do so in response to DAUD.

-- 
Brian F. G. Bidulock
[e-mail]
http://www.openss7.com/