The header of a TCP segment contains several entries, including source and destination ports, sequence and acknowledgment numbers, data offset, flags, window size, and checksum.
The header of a TCP segment that carries a message from an FTP client to an FTP server includes various fields that provide information about the segment. Here are the main entries in the TCP header:
- Source Port: Specifies the port number of the FTP client.
- Destination Port: Specifies the port number of the FTP server.
- Sequence Number: Indicates the number assigned to the first byte of data in the segment.
- Acknowledgment Number: Indicates the next sequence number that the FTP client expects to receive from the server.
- Data Offset: Specifies the size of the TCP header in 32-bit words.
- Flags: Includes various control flags such as SYN, ACK, and FIN.
- Window Size: Indicates the number of bytes that the FTP client can accept.
- Checksum: Provides error detection for the TCP header and data.