The Insteon message that you posted is a Group Broadcast OFF message. It is the first of two messages that are issued by an Insteon device functioning as a Controller. The “to” Insteon address of a Group Broadcast message is the Group number, Group 1 in this case. Parameter 9 is the Flag byte of an Insteon message, the 0xC7 value, the first 4 bits, 0xCx indicates a Group Broadcast type message. Parameter 10 is the Insteon command, 0x13 being an OFF command. This message is the first message I would expect from pressing the Off side of button one on the ControLinc. The Group Cleanup Direct message, the second Insteon message in the sequence, contains the responder device address in the “to” device address.
I would suggest reading the Insteon Details document on the insteon.net web site for details on the content of an Insteon message. That document has a good chart on Flag byte content which describes the type of each Insteon message. Once you know the type of Insteon message, then you will know what the other fields in an Insteon message will contain.