Answer: TCP sequence numbers are 32-bit numbers used to uniquely identify each byte of data in a TCP connection, starting with an initial sequence number (ISN) and incremented for each byte sent.
Working of TCP Sequence Number
1. Numbering the sequence: Just like the parts of your letter, each data segment sent over TCP is numbered. This ensures all segments can be put together in the correct sequence upon arrival.
2. Keeping Track: Both sender and receiver use these numbers to track where they are in the data exchange, preventing any part of the data from getting lost or repeated.
3. Organizing the Arrival: If segments arrive out of order, sequence numbers act as guides to put everything back in the correct order, much like sorting scattered pages of a letter.
4. Avoiding Repetition: These numbers help identify duplicates, preventing the same data segment from being processed twice.
5. Managing Traffic: TCP uses sequence numbers to control the data flow, preventing the network from getting overwhelmed.
6. Securing the Message: Sequence numbers also enhance security by making it complex for tampered data to disrupt the communication.