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

Lincoln,

Haresign Lincoln wrote:                                                           (Thu, 06 Oct 2005 10:50:33)
> Tolga,
> 
> Here is one example of why you have SCON as opposed to detecting it at
> the SCTP level.  An ASP may detect congestion. 
> 
> Let's say that we are implementing an SMSC and the ASPs know that they
> can only handle a certain load based upon the speed of accessing their
> database.  And let's say that the ASP detects some congestion while
> accessing it's database.  It might want to indicate back to the SG that
> it doesn't want to receive new transactions.  So it would send an SCON
> to the SG.
> 
> Regards,
> Lincoln
> 

In this case, new transactions should be aborted by the application, with
U-abort cause indicating database congestion, not returned with P-abort
cause SCCP network congestion.  The application is perfectly capable of
rejecting new transactions.  It is only when there is congestion toward
the signalling point or subsystem that congestion should be signalled.

So, for example, when ISUP encounters call congestion, it signals ACC and
releases IAMs.  It does not send SCON to the SG.

--brian

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