2 byte - header, 00 00 or 00 01 

2 byte length field

4 byte - 04 00 00 80

4 byte - 25 00 00 00
	 45 00 0B 00
         45 00 0A 00

4 byte - sequence number -


for the 546 data packate

00 00
0x21e length
04 00 00 80
- top bit direction in pkts have 0x80
25 00 00 00
02 00 00 00
10 02 84 00 <- another length 
30 ef

Protocol - out