In a Transmission Control Protocol (TCP) header next Expected segment is provided by Acknowledgment Number
Explanation:
TCP is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in the Internet Protocol.
The fields in TCP Segment Header are Source Port, Destination Port, Sequence Number, Acknowledgement Number, Header Length, Flags, Window Size, TCP Checksum and Urgent Pointer.
The Acknowledgment Number is a 32 Bit number field which indicates the next sequence number that the sending device is expecting from the other device.
The SYN packets consume one sequence number, so actual data will begin at ISN+1. The sequence number is the byte number of the first byte of data in the TCP packet sent.
If the acknowledgment flag is set in the flags field, the acknowledgment number field holds the sequence number of the next byte that the receiver expects.
