Re: Congestion in M3UA/SUA and the use of the SCON

Lincoln,

Without knowing any point codes the SCCP-User cannot properly process
received SCON(N-PCSTATE indications) far less generate them.

You need to realize that the SG-ASP interface that we are talking about
is an SCCP/SCCP-User interface.  Congestion, GTT, and the procedures
you speak of are below the SCCP/SCCP-User interface.  It is possible with
SUA to enhance operation with a relay function, but relay nodes are
no longer SG-ASP (they are IPSP).

When we say that an ASP can send SCON to an SG, we are saying that an
SCCP-User can generate N-PCSTATE request to the SCCP.

When sent from the SG (SCCP), and for relay operation, you use the SCON
of the SG->ASP direction.

--brian

Haresign Lincoln wrote:                     (Tue, 11 Oct 2005 13:52:25)
> Brian,
> 
> [brian]: I'm sorry but the concept of an SCCP-User that knows the point
> code of every node in the SS7 network that it might want to send
> messages to, except its own, is not a very useful one.
> 
> I'm sorry to say, but you are mistaken.  Requiring an SCCP user to know
> the point codes of any node in the network is too much overhead for most
> operators for some applications.  For example, a typical SMS application
> deals only with global titles (inbound and outbound).  Operators have no
> desire to provision all the PCs in their network.  They do this in the
> STPs and use GTT all over the place.  This is a basic fact of operation
> in most of the large SS7 networks of the world that are running SMS.  If
> you are going to be running SMS over an SUA SG, you would provision your
> SG with the inbound/outbound GTs.  The outbound GTs would be to an STP
> that would do further GTT to get the message to the MSC or HLR.  You
> really don't want to do any provisioning on your ASPs if you can avoid
> it except for a single GT.  
> 
> Knowledge of global titles is all that is required at an endpoint.
> 
> I'm not sure what you mean by "MUST be included in the source and
> destination addresses of the Registration Request".  Are you referring
> to the PC?  Can you please point out where in the SUA RFC it indicates
> this?  I couldn't find it.
> 
> And no where in the RFC does it indicate that we need to supply the PC
> when sending a message from the ASP to the SG.  Nor does it say that
> when the SG sends a message to the ASP, it needs to supply a PC in the
> destination address.  Certainly you need to supply an Address Indicator
> if you are working with GTT, PC, and/or SSN.  But just like an SCCP user
> today, it does not need to supply a point code in either the calling or
> called address.  If the PC MUST always be present in the
> source/destination address, shouldn't we update the RFC to reflect this?
> All I see is an example of how to use the PC value if the Address
> indicator is set to a certain value.  The AI just provides information
> about how to encode/decode based upon what is present.  If you are
> saying the PC is a MUST, then the RFC should be updated to indicate that
> the source/destination address _MUST_ contain the Point Code parameter.
> 
> 
> Today, that is not the case.  And we can build an ASP that complies to
> the RFC without any knowledge of the PC.  Knowledge of the PC for some
> applications is unnecessary overhead that operators do not want to
> configure.
> 
> 
> Regards,
> Lincoln
> 

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