Thomas Kunz
Systems and Computer Engineering
The TCP Header
Data
Options
16-bit TCP Checksum
16-bit urgent pointer
16-bit window size
32-bit acknowledgment number
16-bit TCP Checksum
16-bit destination port
16-bit source port
32-bit sequence number
0
15
16
31
Identifies sequential TCP segments
The sequence number of the next expected segment
Sometimes called "data offset"
Flags for various controls
Buffer size for received data
Points to the first byte of urgent data
Other options specific to this connection
TCP segment