RE: Multiple SUA SGs, sending for SSP from SGs

Brian,

You also know as much as I do that SCCP (and MTP3 for M3UA) is hosted on
SGs, the interface between SG and ASP mimics SCCP/SCCP-User (MTP3/MTP3-User
interface for M3UA) interface. It is true that for multiple SG scenario ASPs
have a small portion of MTP3 functionality, but this does not mean that MTP3
is actually not hosted on SG, e.g. it is still SG generating management
messages for SCCP/MTP3.

   Tolga

> -----Original Message-----
> From: Brian F. G. Bidulock [mailto:[email protected]]
> Sent: Tuesday, January 10, 2006 5:47 PM
> To: Tolga Asveren
> Cc: [email protected]
> Subject: Re: [Sigtran] Multiple SUA SGs, sending for SSP from SGs
>
>
> Tolga,
>
> Tolga Asveren wrote:                            (Tue, 10 Jan 2006
> 17:08:40)
> >
> > Ah O.K., I forget for a while the "undocumented" relaying
> functionality of
> > SUA :-)
> >
> > In any case, personally I don't see how it may be usefull for
> multiple SG
> > scenario because SCCPs are locally hosted in SGs. Relaying messages is a
> > different story.
>
> SCCPs are only locally hosted at an SG in the pure backhaul case.  In
> the multiple SG as STP scenario, and in the SCCP relay scenario, SCCPs
> can also be hosted at the ASP or IPSP.
>
> M3UA is not so different.  MTPs can be locally hosted at the ASP in the
> multiple SG as STP scenario.  It was always the intention for M3UA to
> support this scenario.
>
> E.g, section 1.3.2 of RFC 3332:
>
>   ... However, in the case where an ASP is connected to more than one
>   SG, the M3UA layer at an ASP should maintain the status of configured
>   SS7 destinations and route messages according to the availability and
>   congestion status of the routes to these destinations via each SG.
>
> Also see Section 1.4.1 and Figure 1.  See also, Figure 5 in the
> Appendix, Appendix A.2.2.  There are additional passages throughout the
> document.
>
> In fact, this is the sole purpose of the DRST message: see section
> 3.4.6.
>
> SUA simply provides the additional mechanism (as does SCCP) of managing
> the availability of SCCP User across such an arrangement.  M3UA provides
> only partial MTP User availabilty (DUPU) management, as does MTP3 (UPU).
>
> These are fundamental capabilities required to meet the objective of
> providing transparent interworking to the SS7 network.
>
> --brian
>
> --
> Brian F. G. Bidulock
> [email protected]
> http://www.openss7.org/
>