Re: RFC 4666 on Signaling System 7 (SS7) MessageTransferPart 3 (MTP3) - User Adaptation Layer (M3UA)

Tolga,

It was always the intention of the SIGTRAN protocols that
they support multiple associations between ASP and SGP.
See, for example, Figure 5 in RFC 3332.  That figure shows
a near full mesh of SCTP associations between SGP and ASP.

The purpose of multiple hosts in an SG or MGC is reliability.
If you place one association between them, you have a single
point of failure.  Carrier grade systems are designed for
no single point of failure.  To ensure no SPOF, you need
multiple SGP in an SG, multiple SG, and multiple ASPs in
an MGC.

M3UA cannot handle sequenced changeover or changeback
between associations without message loss (or worse,
duplication) using local procedures.  A protocol mechanism
such as corid is necessary.

SS7 does this (all day long).  CORID is precisely the SS7
procedures applied to SIGTRAN.

If there is some point(s) in the draft that you disagree
with perhaps you could quote them and make some suggestions
for improvement.

--brian

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