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

[Ajay Garg <[e-mail]>]

Thanks a ton David for the clarifications !!


On Thu, Mar 13, 2014 at 4:23 PM, David Laight <[e-mail]>wrote;wrote:

>  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.
>

Yep, we are in a position to configure Global-Title-Translation (GTT) rules
on N2, which will enable us to "route" messages from N1 -> N3, and N3 -> N1.




However, the above makes us wonder on the following question ::

Assuming all nodes (N1, N2, N3) are pure SIGTRAN-nodes (no SS7 nodes), is
it ever required at all to make N2 a SGP ?
(Of course, that would also mean changing the links between N1 <-> N2, and
N2 <-> N3 to ASP <-> SGP types)


Looking forward to more clarifications !!


Thanks and Regards,
Ajay




>
>
>                 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]> 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]
> http://www.openss7.org/
>
>
>
>
> --
> Regards,
> Ajay
>
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1
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>
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>


-- 
Regards,
Ajay