Other applications, which do not require reliable data stream service, may use the User Datagram Protocol ( UDP ), which provides a datagram service that emphasizes reduced latency over reliability.

UDP provides no guarantees to the upper layer protocol for message delivery and the UDP protocol layer retains no state of UDP messages once sent.

UDP provides application multiplexing ( via port numbers ) and integrity verification ( via checksum ) of the header and payload.

For example, Internet Protocol ( IP ) provides an unreliable service and UDP over IP is also unreliable.

GENA Base Client to Arbiter provides for the ability to send and receive notifications using HTTP over TCP / IP and administratively scoped unreliable multicast UDP.

CLNS is not an Internet service, but provides capabilities in an OSI network environment similar to those provided by the Internet Protocol ( IP ) and the User Datagram Protocol ( UDP ).

Other possibilities include RFC 1006 ( which provides an ISO transport service on top of TCP ), and CMIP over LPP ( a presentation layer protocol that can run on top of TCP or UDP ).

Because it operates at the IP network layer, CBQ provides the same benefits across any Layer 2 technology and is equally effective with any IP protocol, such as Transmission Control Protocol ( TCP ) and User Datagram Protocol ( UDP ).

Like RADIUS, Diameter provides AAA functionality but in addition it is made more reliable by using TCP and SCTP instead of UDP.

It also provides the functions expected of a modern scripting language, including support for regular expressions, XML, Unicode ( UTF-8 ), TCP / IP and UDP networking, matrix and array processing, advanced math, statistics and Bayesian statistical analysis, financial mathematics, and distributed computing support.

The program decodes and provides the user with all NetBIOS name packets it receives on UDP port 137.

These extensions include intelligent query routing, SHA-1 checksums, query hit transmission via UDP, querying via UDP, dynamic queries via TCP, file transfers via UDP, XML meta data, source exchange ( also termed the download mesh ) and parallel downloading in slices ( swarming ).

DHCP uses the same two ports assigned by IANA for BOOTP: destination UDP port 67 for sending data to the server, and UDP port 68 for data to the client.

Various methods have been used for this, including a pre-existing address list of possibly working nodes shipped with the software, using updated web caches of known nodes ( called Gnutella Web Caches ), UDP host caches and, rarely, even IRC.

However HTTP can use unreliable protocols such as the User Datagram Protocol ( UDP ), for example in Simple Service Discovery Protocol ( SSDP ).

Some applications use a simpler, connection-less transport protocol, User Datagram Protocol ( UDP ), for tasks which do not require reliable delivery of data or that require real-time service, such as video streaming or voice chat.

The tracert ( traceroute ), Pathping commands are implemented by transmitting UDP datagrams with specially set IP TTL header fields, and looking for ICMP Time to live exceeded in transit ( above ) and " Destination unreachable " messages generated in response.

Version numbers 6 through 9 were proposed for various protocol models designed to replace IPv4: SIPP ( Simple Internet Protocol Plus, known now as IPv6 ), TP / IX ( RFC 1475 ), PIP ( RFC 1621 ) and TUBA ( TCP and UDP with Bigger Addresses, RFC 1347 ).

The default port for the RTSP protocol is 554 for both UDP ( deprecated and very rarely used ) and TCP transports.

The User Datagram Protocol ( UDP ) is one of the core members of the Internet protocol suite, the set of network protocols used for the Internet.

UDP is suitable for purposes where error checking and correction is either not necessary or performed in the application, avoiding the overhead of such processing at the network interface level.

Time-sensitive applications often use UDP because dropping packets is preferable to waiting for delayed packets, which may not be an option in a real-time system.

Since the magic packet is only scanned for the string above, and not actually parsed by a full protocol stack, it may be sent as any network-and transport-layer protocol, although it is typically sent as a UDP datagram to port 7 or 9, or directly over Ethernet as EtherType 0x0842.

Some Transport Layer protocols, for example TCP, but not UDP, support virtual circuits provide connection oriented communication over an underlying packet oriented datagram network. Where it assures the delivery of packets in the order in which they were sent and assure that they are free of errors. The datagram transportation deliver the packets randomly and broadcast it to multiple nodes.

# The Layer 4 ( Transport Layer ) PDU is the segment for TCP, or the datagram for UDP

ICMP differs from transport protocols such as TCP and UDP in that it is not typically used to exchange data between systems, nor is it regularly employed by end-user network applications ( with the exception of some diagnostic tools like ping and traceroute ).

Sample encapsulation of application data from User Datagram Protocol | UDP to a Link protocol frame

With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol ( IP ) network without requiring prior communications to set up special transmission channels or data paths.

Protocol analyzers vary in their abilities to display data in multiple views, automatically detect errors, determine the root causes of errors, generate timing diagrams, reconstruct TCP and UDP data streams, etc.

UDP transmissions are preferred as they do not require testing for dropped packets and as such since each T. 38 packet transmission includes a majority of the data sent in the prior packet, a T. 38 termination point has a higher degree of success in re-assembling the fax transmission back into its original form for interpretation by the end device.

UPnP uses UDP due to its lower overhead in not requiring confirmation of received data and retransmission of crc failed packets.

These extensions are designed to reduce the overhead of the user to kernel mode transition for the network data path and the notification path, but use the rest of the regular Windows TCP and UDP stack ( and uses existing network cards ).

In contrast with the Wireless Application Protocol ( WAP ) standard, which used Wireless Markup Language ( WML ) on top of a protocol stack for wireless handheld devices, i-mode borrows from fixed Internet data formats such as C-HTML based on HTML, as well as DoCoMo proprietary protocols ALP ( HTTP ) and TLP ( TCP, UDP ).

IAX2 uses a single UDP data stream ( usually on port 4569 ) to communicate between endpoints, multiplexing signaling and media flow.

In the case of transport protocols that do not implement a formal session layer ( e. g., UDP ) or where sessions at the session layer are generally very short-lived ( e. g., HTTP ), sessions are maintained by a higher level program using a method defined in the data being exchanged.

The telescopes are then linked via high-speed national research and education networks ( NRENs ) which overcome some of the performance drawbacks of TCP / IP and UDP / IP ( networking protocols ) to allow sharing large volumes of data for immediate use.

UDP, often used in computer games or other situations where speed is an issue and the loss of a little data is not as important because of the transitory nature of the data, is an unreliable protocol.

* Raw UDP socket connection: For use with UDP based applications, terminal servers can convert serial equipment data for transport across UDP packets on a point-to-point basis or shared across multiple devices.

* The IPv6 header is not protected by a checksum ; integrity protection is assumed to be assured by both link-layer and higher-layer ( TCP, UDP, etc.

DNS primarily uses User Datagram Protocol ( UDP ) on port number 53 to serve requests.

An HTTP client initiates a request by establishing a Transmission Control Protocol ( TCP ) connection to a particular port on a server ( typically port 80 ; see List of TCP and UDP port numbers ).

* TCP and UDP port numbers

On Unix-like operating systems, the traceroute utility by default uses User Datagram Protocol ( UDP ) datagrams with destination port numbers from 33434 to 33534.

This can help identify incorrect routing table definitions or firewalls that may be blocking ICMP traffic, or high port UDP in UNIX ping, to a site.

The SNMP agent receives requests on UDP port 161.

RIP uses the User Datagram Protocol ( UDP ) as its transport protocol, and is assigned the reserved port number 520.

RIPng sends updates on UDP port 521 using the multicast group FF02 :: 9.

It is a Cisco proprietary protocol that runs on port UDP / 4500.

It has been implemented on top of the User Datagram Protocol ( UDP ) using port number 69.

* List of TCP and UDP port numbers

The vast bulk of Internet traffic is TCP and UDP packets, and for these protocols the port numbers are changed so that the combination of IP and port information on the returned packet can be unambiguously mapped to the corresponding private address and port information.

In the Transport Layer ( Layer 4 ) the cable modem supports UDP in association with its own IP address, and it supports filtering based on TCP and UDP port numbers to, for example, block forwarding of NetBIOS traffic out of the customer's LAN.