Browse Prior Art Database

User Datagram Protocol (RFC0768)

IP.com Disclosure Number: IPCOM000003816D
Original Publication Date: 1980-Aug-28
Included in the Prior Art Database: 2000-Sep-13
Document File: 3 page(s) / 6K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Postel: AUTHOR

Abstract

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This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 52% of the total text.

RFC 768 J. Postel

ISI

28 August 1980

User Datagram Protocol

----------------------

Introduction

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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].

Format

------

0 7 8 15 16 23 24 31

+--------+--------+--------+--------+

| Source | Destination |

| Port | Port |

+--------+--------+--------+--------+

| | |

| Length | Checksum |

+--------+--------+--------+--------+

|

| data octets ...

+---------------- ...

User Datagram Header Format

Fields

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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.

28 Aug 1980

User Datagram Protocol RFC 768

Fields

Destination Port has a meaning within the context of a particular

internet destination address.

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 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.

The pseudo header conceptually prefixed to the UDP header contains the

source address, the destination address, the protocol, and the UDP

length. This information gives protection against misrouted datagrams.

This checksum procedure is the same as is used in TCP.

0 7 8 15 16 23 24 31

+--------+--------+--------+--------+

| source address ...