Subject: [Sigtran] (M3UA) Concern about lossy nature of M3UA connections in certain configurations

From: [email-masked]
Date: Fri, 31 May 2002 09:31:06 -0400

Hello All,

I am concerned about the lossy nature of M3UA connections for the following
scenario:

     Very high bandwidth is required between two M3UA-connected nodes.
     The scalable architecture of each side makes the node appear as a set
of
     SCTP multi-homed nodes, called 'blades', and so a single association
     cannot be used to connect the two nodes.  A single association cannot
     connect more than two blades (multi-homing does not cross blades).
     Multiple associations are used, perhaps one per blade.  A single point
     of failure is an association failing (blade failing).

Messages will be lost, since full retrieval below the SCTP layer is not
possible.
(Discussion of the challenges involved in SCTP retrieval is beyond the
scope of
this posting). M3UA lacks the facility to enable full retrieval.

Is the answer simply that M3UA (even M3UA SG-SG) does not support loss-less
connectivity between two nodes connected by multiple associations, when an
association fails? Is the consensus that this message loss is acceptable?

Just curious.

Regards,

Jeff

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From: "Tolga Asveren" <[email-masked]>
Date: Fri, 31 May 2002 10:31:36 -0400

Jeff,

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]]On Behalf Of
> [email-masked]
> Sent: Friday, May 31, 2002 9:31 AM
> To: [email-masked]
> Subject: [Sigtran] (M3UA) Concern about lossy nature of M3UA connections
> in certainconfigurations
>
>
> Hello All,
>
[TOLGA] There is CORID draft to prevent message
loss/duplication/missequencing for the cases you describe. But I also want
to ask, what happens when your STP in SS7 network crashes (host is down) ,
can you retrieve any messages from there, or can its peers follow changeover
procedures and decide which messages have been already received by that STP?

---

From: "Brian F. G. Bidulock" <[email-masked]>
Date: Fri, 31 May 2002 09:48:54 -0500

Jeffrey,

See draft-bidulock-sigtran-corid-00.txt for a discussion of same
and a proposed solution.  This is the only proposed solution to
avoid message loss in such a scenario.  Not even implementing full
retrieval would help you completely.

--brian

[email-masked] wrote:         (Fri, 31 May 2002 09:31:06)

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