Connection Oriented SCCP

As a continuation of the last post I wrote, in this one I present another couple of capture files showing, this time, brief examples of  SCCP connection oriented services.

The first log shows the complete lifecycle - i.e. establishment / data transfer / release - of a class 2 connection, while the other one shows that of a class 3 connection. The two logs can be viewed with Wireshark configured in the same way as for the connectionless examples.

Protocol class 2 provides a simple connection oriented service with no freals except for segmentation and reassembly, while class 3 adds flow control and detection of losses and mis-sequencing of user messages, although with no error recovery mechanism.

Please note that in the class 3 example I chose a very small window size just to keep it short and simple.