Netmeeting call setup – a call trace

With an attempt to understand the call setup procedures within two Netmeeting clients, I have captured the following trace:

1)
Client_1 (calling side – port 1948) and client 2 (called side – port 1972)have established a TCP connection and ready to start the call setup.

2)
Client_1 sends the following TCP data to Client_2:
03 00 00 DA

3)
Client 2 replies with an Ack.

4)
Client_1 sends the Q.931 setup message to Client_2:
08 02 11 22 05 04 03 88 C0 A5
28 0A 54 64 20 …..

My question is:
– what kind of message is in 2)
i.e. 03 00 00 DA

– any suggestions on more references.

Many thanks for your reply.

leo