The size of a usual UDP header is 8 bytes; the data that is added with the header can be theoretically 65,535 (practically 65,507) bytes long. A UDP header is quite small when compared to a TCP header; it has just four common fields: Source Port, Destination Port, Packet Length, and Checksum. Refer to the UDP header shown here:
- Source port: Port number used by the sending side to receive any replies if needed. Most of the time, in a TCP and UDP, the port number chosen to be the part of the socket is ephemeral.
- Destination port: Port number used by the receiving side, where all data is transmitted to.
- Packet length: Specifies ...
