Stop

The 2 bytes after the prefix and protocol version indicate the length of the message which gives you a stop point.

In total the first 5 bytes would look something like this with a prefix:

0x4c 0x42 0x03 0x0b 0x00 or 76 66 3 11 0.

Or with no prefix:

0x03 0x0b 0x00 or 3 11 0.