Section: udp
Family Number
IPV4 17
IPV6 17

Endian: endian_big
Protocol description
Reference: RFC-768

This User Datagram Protocol (UDP) is defined to make available a datagram mode of packet-switched computer communication in the environment of an interconnected set of computer networks. This protocol assumes that the Internet Protocol (IP) [1] is used as the underlying protocol.

This protocol provides a procedure for application programs to send messages to other programs with a minimum of protocol mechanism. The protocol is transaction oriented, and delivery and duplicate protection are not guaranteed. Applications requiring ordered reliable delivery of streams of data should use the Transmission Control Protocol (TCP) [2].

Name: Hdr
Name: Hdr
Field name Field type Field size Field description
source_port Integer 16 Source Port is an optional field, when meaningful, it indicates the port of the sending process, and may be assumed to be the port to which a reply should be addressed in the absence of any other information. If not used, a value of zero is inserted.
destination_port Integer 16 Destination Port has a meaning within the context of a particular internet destination address.
length Integer 16 Length is the length in octets of this user datagram including this header and the data. (This means the minimum value of the length is eight.)
checksum Integer 16 Checksum is the 16-bit one's complement of the one's complement sum of a pseudo header of information from the IP header, the UDP header, and the data, padded with zero octets at the end (if necessary) to make a multiple of two octets.
payload Binary Large Object - (This is the payload. It is (length - 8) octets long.)

RCS ID: "$Id: udp.xml,v 1.7 2001/10/29 06:23:30 tlewis Exp $"