Re: M3UA: SCON: congestion condition never abates

I presume this is (supposed to be) M3UA?

M3UA is an abstraction of the interface between MTP3 and its userparts (typically SCCP and ISUP).

This means that the ‘AS’ box isn’t running MTP3, so your descriptions about routing are incorrect.

 

The M3UA SCON indication is telling the userpart that MTP3 received a TFC for the route.

This could be used by the userpart to reduce its traffic.

There is no network message that indicates that congestion has ceased.

IIRC M3UA also doesn’t contain any such message.

The ‘congestion level’ will be 1, 2 or 3 in ansi networks, and always 0 in ITU networks.

 

                David

 

From: [email protected] [mailto:[email protected]] On Behalf Of urte plesske
Sent: 23 October 2012 15:58
To: [email protected]
Subject: [Sigtran] M3UA: SCON: congestion condition never abates

 

Hello, I'm faced with a problem based on the following architecture:

AS connected to two SGs
   AS
  /  \
 /    \
SG1---SG2
SCCP: SGs are making GTTs to route to the ss7 network.
MTP configurations on AS:
There are two routesets defined on AS, one to SG1 (containing direct route and route over SG2) and to SG2 (containing direct route and route over SG1)
 
SCON message was received by AS from SG2 with affected PC SG1.
On AS the route set (PC SG1) was inhibited. No traffic was sent to SG1 by AS any more. 
 
Usually the AS would start sending periodic DAUDs messages as a result of the congestion, but because SG1 was got to know as adjacent node, no DAUDs with affected Point Code = Point Code SG1 were sent by any ASP.
No SCON messages were sent by SG2 to AS because no DATA and DAUD messages were received to react.
The congestion condition never abates.
 
Could you please help me with the following questions:
How to solve this situation (timer on AS?)? 
Is it correct not to audit adjacent nodes?
Can (should) SG2 send a SCON message even there are no DATA and DAUD messages to react?  
Where can I find (rfc) the information, that SCON is like TFC and not TFR?
 
Thanks a lot!
 
regards, urte

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