Re: Sigtran interworking issue between multivendor node

From: Pradeep4 Kumar
> I am assuming that the open MGW and AOIP BSC are connection over the IPSP communication type. Correct
> if I am wrong?
> 
> IPSP is point to point communication so DAUD is not expected message on IPSP communication mode.
> 
> So the receiving end point must drop the DAUD message and also this end point can optionally send back
> Management Error  message with error as "Unexpected Message".
...

Although M3UA almost always carries the MTP3 service interface over SCTP at least
one major manufacturer has a configuration option where M3UA IPSP links seems to
be used to pass messages between MTP3 systems.

Configured that way it requires the IPSP system to answer DAUD (for its own pointcode)
and to not error DAVA and DUNA.

If you look at section 1.5.3 the M3UA connection appears to be an IPSP one between
the ASP on the right and SCCP in the middle.
However there is also a direct link shown between the MTP3 and M3UA.
It isn't clear to me which messages would use that link, but it might
be the justification (or documentation!) of this unusual mode.

	David