IPv4 is a connectionless protocol for use on packet-switched Link Layer networks ( e. g., Ethernet ).

Cell relay is an implementation of fast packet-switching technology that is used in connection-oriented broadband integrated services digital networks ( B-ISDN, and its better-known supporting technology ATM ) and connectionless IEEE 802. 6 switched multi-megabit data service ( SMDS ).

In packet switching networks, CL-mode or connectionless communication is a data transmission method in which each data packet carries information in a header record that contains a destination address sufficient to permit the independent delivery of the packet to its destination via the network.

In telecommunication, a distributed-queue dual-bus network ( DQDB ) is a distributed multi-access network that ( a ) supports integrated communications using a dual bus and distributed queuing, ( b ) provides access to local or metropolitan area networks, and ( c ) supports connectionless data transfer, connection-oriented data transfer, and isochronous communications, such as voice communications.

The service actually provided to the user by networks using packet switching nodes can be either connectionless ( based on datagram messages ), or virtual circuit switching ( also known as connection oriented ).

While the ISODE implementation could be configured to use one of several X. 25 ( CONS ) or connectionless lower layer protocols, many ISODE deployments were based on 1006, the implementation of OSI transport protocol TP0 as a layer atop TCP, in order to use IP-based networks which were becoming increasingly common.

Connection-oriented protocols handle real-time traffic substantially more efficiently than connectionless protocols, which is why ATM has yet to be replaced with Ethernet for carrying real-time, isochronous traffic streams, especially in heavily aggregated networks like backbones, where the motto " bandwidth is cheap " fails to deliver on its promise.

* The network nodes are faster and have higher capacity in theory, since they are switches that only perform routing during the connection establishment phase, while connectionless network nodes are routers that perform routing for each packet individually.

In connectionless routing, each packet is treated separately, making its way through the network independently.

It performs the multiple PDP Context PDU transfers and it also ensures that NPDUs from each PDP Context are transmitted to the LLC layer in sufficient time to maintain the QoS. SNDCP provides services to the higher layers which may include connectionless and connection-oriented mode, compression, multiplexing and segmentation.

A packet transmitted in a connectionless mode is frequently called a datagram.

Unfortunately, in connectionless mode transmission of a packet, the service provider usually cannot guarantee that there will be no loss, error insertion, misdelivery, duplication, or out-of-sequence delivery of the packet.

Connection oriented transport layer datalink protocols such as TCP may rely on a connectionless packet switching network layer protocol such as IP, where different packets may be routed over different paths, and thus be delivered out of order.

Advantages with this over connectionless packet switching are:

Two major packet switching modes exist ; ( 1 ) connectionless packet switching, also known as datagram switching, and ( 2 ) connection-oriented packet switching, also known as virtual circuit switching.

Datagram packet switching is also called connectionless networking because no connections are established.

Because UDP is connectionless, there is no standard method to inform the sending client that a message was received, and so if the packet is lost, there is no way to know.

UDP is a connectionless protocol so there is no equivalent to a TCP SYN packet.

* AAL Type 3 / 4 supports VBR, data traffic, connection-oriented, asynchronous traffic ( e. g. X. 25 data ) or connectionless packet data ( e. g. SMDS traffic ) with an additional 4-byte header in the information payload of the cell.

The AAL 5 was designed to accommodate the same variable bit rate, connection-oriented asynchronous traffic or connectionless packet data supported by AAL 3 / 4, but without the segment tracking and error correction requirements.

A connection-oriented transport layer protocol, such as TCP, may be based on a connectionless network layer protocol ( such as IP ), but still achieve in-order delivery of a byte-stream, by means of segment numbering on the sender side and data packet reordering on the receiver side.

In 1997, Pouzin received the ACM SIGCOMM Award for " pioneering work on connectionless packet communication ".

* Type 1 is an unacknowledged connectionless mode for a datagram service.

* Type 3 is an acknowledged connectionless service.

Indeed, the " connectionless " http traffic that is used to populate this very page is without a doubt transported ( in the MAN and WAN ) within SONET frames.

In concept, burst switching is similar to connectionless mode transmission, but differs in that burst switching implies an intent to establish the switch connection in near real time so that only minimum buffering is required at the node switch.

Another drawback of the connectionless mode is that no optimizations are possible when sending several frames between the same two peers.

UDP is connectionless.

It is a connectionless, best effort, unreliable, message delivery service.

* Transmission Control Protocol ( TCP ), where a reliable virtual circuit is established on top of the underlying unreliable and connectionless IP protocol.

The " fast select with restricted response facility " is intermediate between full call establishment and connectionless communication.

Thus a virtual connection, also known as a virtual circuit or byte stream is provided to the end-user by a transport layer protocol, although intermediate network nodes only provides a connectionless network layer service.

: For example, IP is connectionless, in that a datagram can travel from a sender to a recipient without the recipient having to send an acknowledgement.

It is used for connection-oriented transmissions, whereas the connectionless User Datagram Protocol ( UDP ) is used for simpler messaging transmissions.

Datagram mode is " connectionless ".

Datagram mode is " connectionless ".

* Unnumbered format PDUs, or U-format PDUs, with an 8-bit control field, which are intended for connectionless applications ;

TP4 provides reliable transport service and functions with either connection-oriented or connectionless network service.

The impact is so great, in fact, that even characteristically connectionless protocols, such as IP traffic, are being tagged with connection-oriented header prefixes ( e. g., as with MPLS, or IPv6's built-in Flow ID field ).

The classification is based on whether a timing relationship must be maintained between source and destination, whether the application requires a constant bit rate, and whether the transfer is connection oriented or connectionless.

* Datagram distribution service for connectionless communication ( port: 138 )