User Datagram Protocol

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user datagram protocol

[‚yüz·ər ′dad·ə‚gram ‚prōd·ə‚kȯl]
A communications protocol providing a direct way to send and receive datagrams over an IP network but with few error recovery resources, used mainly for broadcasting over a network, for example, with streaming media.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

User Datagram Protocol

(UDP) Internet standard network layer, transport layer and session layer protocols which provide simple but unreliable datagram services. UDP is defined in STD 6, RFC 768. It adds a checksum and additional process-to-process addressing information UDP is a connectionless protocol which, like TCP, is layered on top of IP.

UDP neither guarantees delivery nor does it require a connection. As a result it is lightweight and efficient, but all error processing and retransmission must be taken care of by the application program.

Unix manual page: udp(4).

[Postel, Jon, User Datagram Protocol, RFC 768, Network Information Center, SRI International, Menlo Park, Calif., August 1980].
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(User Datagram Protocol) A TCP/IP protocol that is widely used for streaming audio and video, voice over IP (VoIP) and videoconferencing. UDP is considered an unreliable delivery protocol because it does not check for errors. When transmitting voice and video, there is no time to retransmit erroneous or dropped packets. In contrast, when financial and other data are transmitted, TCP is used, which does check for errors.

UDP is "connectionless" and does not use a handshake to start a session like TCP does. For example, in a broadcast session with multiple destinations, UDP does not set up a connection with each receiver beforehand. See TCP, TCP/IP and RTP.

UDP Within an Ethernet Frame
A UDP packet is framed just like a TCP packet. This shows a UDP packet in an Ethernet frame ready for transmission over the network.

The Transport Layer of TCP/IP
The transport layer of the TCP/IP protocol defines both unreliable (UDP) and reliable (TCP) delivery methods.
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References in periodicals archive ?
Dozens of statistics are stored until the end of the communications, at which time the contents of the flow cache are sent across the network in a specially formatted user datagram protocol (UDP) packet called a NetFlow protocol data unit (PDU)." A "flow collector" receives the PDU and analyzes its contents, reconstructing a full picture of the flows occurring on all routers.
There are a large number of "protocols" used to transmit different types of traffic across the Internet Some, such as HTTP (hypertext transport protocol), are used for normal Web traffic, others, such as UDP (user datagram protocol), are used to send streaming audio files.
User datagram protocol is the other primary underlying layer.
We didn't have the AFATDS set us up as an AFATDS, because AFATDS machines do not use USMTF to communicate with each other--they use proprietary user datagram protocol packet transmissions.
Remove unneeded services, All services present some form of exposure because they are listening on a TCP (transmission control protocol) or UDP (user datagram protocol) port, so eliminating unnecessary services diminishes the number of target entry points for intruders.
Well-known IP protocols such as NFS used to use a basic data transport mechanism called UDP (user datagram protocol), which was only semi-unreliable.
Similar probes to examine FTP ports, pcAnywhere[TM] ports, and UDP (User Datagram Protocol) ports are common.
-- The User Datagram Protocol (UDP) and Transmission Control Protocol (TCP)
This gateway applies security mechanisms when a TCP or user datagram protocol (UDP) connection is established.
User Datagram Protocol (UDP) (see Table II) provides CL, uncontrolled-loss, maybe-duplicates, unordered service [Postel 1980].
UDP (User Datagram Protocol): An Internet Standard transport layer protocol.