Subject: [Sigtran] M3UA error "No Configured AS for ASP”

From: Suchetha P <[email-masked]>
Date: Sat, 1 Oct 2016 05:59:45 +0000 (UTC)

Hi,

IuPS interface(Packet switching/data interface) between the nodes  Signalling Gateway and SGSN is down after the Trillium SIGTRAN Stack Upgrade.
This is because of the M3UA error "No o Configured AS for ASP”.

1)    The asExhangeMode is set to “singleExchange” at Signalling Gateway while at SGSN side asExhangeMode is set to “doubleExchange”.
2)    Both the nodes are sending ASPUP & ASPUPACK. SG(Signalling Gateway) then sends ASPAC and SGSN responds with ASPAC Ack. SGSN sends ASPAC but SG doesn’t respond with ASPAC Ack and instead it sends error message “ No Configured AS for ASP”.

We need to investigate why SG is not responding with ASPAC Ack message and instead sending Error message towards  SGSN. 
Can this be a configuration issue ?Or a bug ?The same configuration was working before the Trillium upgrade.
Is it proper to have one node in single exchange mode while the other as double exchange ?
Is the error being thrown for no routing context in the ASP AC message ?

Best Regards,
Suchetha