TCP Sequence Number and Segmentation Visualization

How TCP Sequencing Works

TCP assigns a sequence number to each byte in the data stream. The sequence number field in the TCP header contains the sequence number of the first byte in the segment. This helps the receiver:

• Reassemble segments that arrive out of order
• Identify and eliminate duplicate data
• Request retransmission of missing segments

The Maximum Segment Size (MSS) determines how many bytes can be sent in a single TCP segment. The acknowledgment (ACK) number in the response indicates the next byte expected by the receiver.