User Datagram Protocol

TFTP uses UDP to transfer it's data.

Protocol Stack
Local Medium
Internet Protocol
UDP
TFTP Frame

The UDP header consists of the following fields.

FieldType
Source Portu16
Destination Portu16
Lengthu16
Checksumu16
  • Port number: Port numbers as a way to identify a service. Suppose you want to send a mail to your friend, his hotel address is "Main Street, Anytown, USA" and room number is "123", You can think street address as a IP address and room number as a Port number.

  • Length: Length field defines the length of the message in bytes. Maximum value of u16 bit integer is 65535. However, the actual length of the message is 65,507 bytes* (65,535 − 8 bytes UDP header − 20 bytes IP header)

  • Checksum: The checksum field may be used for error-checking of the header and data. This field is optional in IPv4, and mandatory in IPv6.