Re: [Sigtran] Conceptual doubt between an ASP and SGP

[David Laight <[e-mail]>]

M3UA can’t itself transfer your messages directly from N1 to N3.
It is worth remembering that M3UA carries the interface between MTP3 and its user parts
(typically ISUP and SCCP) over IP.
IPSP seems a ‘bodge’ that more or less works and allows the userparts (at different pointcodes)
to send message to each other.

In your case the SCCP code at node N2 could forward messages that arrive from N1 onwards
to N3. Whether the SCCP you have can be configured to do that is another matter.

                David


From: Sigtran [mailto:[e-mail]] On Behalf Of Ajay Garg
Sent: 13 March 2014 10:05
To: [e-mail]; [e-mail]
Subject: Re: [Sigtran] Conceptual doubt between an ASP and SGP

Brian,
RFC-2719 seems to be too technical for the use-case we are trying to understand :)
I would rather present (a simplified version of) our use-case.
*
We have 3 nodes - N1, N2, N3.
*
We need to transfer messages in-between N1 and N3.
*
There is an IPSP-IPSP association each between between N1 <-> N2, and N2 <-> N3 (but no IPSP-IPSP association between N1 <-> N3).
*
Also, provisions for GTT are available at each of N1, N2 and N3.


Theoritically/Practically, would the above configuration work? Or is it necessary to have a SGP configured at N2?

Looking forward to clarifications.

Thanks and Regards,
Ajay


On Thu, Mar 13, 2014 at 12:47 PM, Brian F. G. Bidulock <[e-mail]<mailto:[e-mail]>> wrote:
Ajay,

Please see comments below...

Ajay Garg wrote:                              (Thu, 13 Mar 2014 11:48:19)
>    Hi all.
>    I am an absolute newbie in telecom domain, so kindly forgive me if I
>    sound incredibly stupid.
>    From what I understand, an ASP is a process running on an AS, and a SGP
>    is a process running on a SG.
Not quite.  See RFC 4666 "1.2 Terminology" for a definition of ASP,
AS, SGP and SG.

>    Each ASP <-> SGP link is a SCTP connection.
>    Also, I understand that SGP is responsible for message-routing, while
>    an ASP is merely an end-point for a SCTP connection.
>    Given that, are there any extra differences between a ASP and SGP (in
>    addition to the routing-capabilities of a SGP)?
>    I will be grateful for any pointers/clarifications.
RFC 4666 describes for 124 pages the differences between ASP and SGP.

BTW, it is not an SGP per se that has routing capabilities, but an
SG, where the SG is made up of some SGP, an SS7 stack and a
interworking function.

See also RFC 2719 "Framework Architecture for Signaling Transport"
for a better overview of what's going on.

--brian

--
Brian F. G. Bidulock
[e-mail]<mailto:[e-mail]>
http://www.openss7.org/



--
Regards,
Ajay