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GSM DTAP malformed packet
Hello everyone.
I've got a packet that is technical a call setup from a PRI plugged into a Cisco AS5400. This message is passed via IUA to a server.
Wireshark sees this as "Stream Control Transmission Protocol" > ISDN Q.921-User Adaptation Layer > Radio Signalling Link (RSL) > GSM A-I/F DTAP.
Wireshark complains that this is a malformed GSM DTAP message. And doesn't seem to display any of the raw ISDN message as it comes off the PRI (I'm looking for stuff like called number, source number..etc). I know it's in this particular packet, Because it can be seen in the lower raw section.
I'm not really sure what the message should be. But I don't think it's RSL. Disabling RSL and GSM DTAP just leave the data undecoded.
Screenshot
http://cdn.141networks.com/images/malformed.PNG