Connection-oriented communication

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: "Connection-oriented communication" – news · newspapers · books · scholar · JSTOR  (June 2019) (Learn how and when to remove this template message)

This article relies excessively on references to primary sources. Please improve this article by adding secondary or tertiary sources. Find sources: "Connection-oriented communication" – news · newspapers · books · scholar · JSTOR  (June 2019) (Learn how and when to remove this template message)

Connection-oriented communication

Connection-oriented communication is a network communication mode in <a href="/en/Telecommunication" title="Telecommunication" class="mw-redirect wl">telecommunications</a> and computer networking, where a <a href="/en/Communication_session" title="Communication session" class="mw-redirect wl">communication session</a> or a semi-permanent connection is established before any useful data can be transferred. The established connection ensures that data is delivered in the correct order to the upper communication layer. The alternative to connection-oriented transmission is <a href="/en/Connectionless_communication" title="Connectionless communication" class="wl">connectionless communication</a>, for example the <a href="/en/Datagram" title="Datagram" class="wl">datagram</a> mode communication used by <a href="/en/Internet_Protocol" title="Internet Protocol" class="wl">Internet Protocol</a> (IP) and <a href="/en/User_Datagram_Protocol" title="User Datagram Protocol" class="wl">User Datagram Protocol</a>, where data may be delivered out of order, since different <a href="/en/Network_packet" title="Network packet" class="wl">network packets</a> are routed independently and may be delivered over different paths.


<style data-mw-deduplicate="TemplateStyles:r1097763485" typeof="mw:Extension/templatestyles mw:Transclusion">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}html.client-js body.skin-minerva .mw-parser-output .mbox-text-span{margin-left:23px!important}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}</style><style data-mw-deduplicate="TemplateStyles:r1086701767" typeof="mw:Extension/templatestyles">.mw-parser-output .multiple-issues-text{width:95%;margin:0.2em 0}.mw-parser-output .multiple-issues-text>.mw-collapsible-content{margin-top:0.3em}.mw-parser-output .compact-ambox .ambox{border:none;border-collapse:collapse;background-color:transparent;margin:0 0 0 1.6em!important;padding:0!important;width:auto;display:block}body.mediawiki .mw-parser-output .compact-ambox .ambox.mbox-small-left{font-size:100%;width:auto;margin:0}.mw-parser-output .compact-ambox .ambox .mbox-text{padding:0!important;margin:0!important}.mw-parser-output .compact-ambox .ambox .mbox-text-span{display:list-item;line-height:1.5em;list-style-type:disc}.mw-parser-output .compact-ambox .ambox .mbox-image,.mw-parser-output .compact-ambox .ambox .mbox-imageright,.mw-parser-output .compact-ambox .ambox .mbox-empty-cell,.mw-parser-output .compact-ambox .hide-when-compact{display:none}</style>

Connection-oriented communication may be implemented with a <a href="/en/Circuit_switched" title="Circuit switched" class="mw-redirect wl">circuit switched</a> connection, or a packet-mode <a href="/en/Virtual_circuit" title="Virtual circuit" class="wl">virtual circuit</a> connection. In the latter case, it may use either a transport layer virtual circuit protocol such as the <a href="/en/Transmission_Control_Protocol" title="Transmission Control Protocol" class="wl">TCP</a> protocol, allowing data to be delivered in order. Although the lower-layer switching is connectionless, or it may be a <a href="/en/Data_link_layer" title="Data link layer" class="wl">data link layer</a> or <a href="/en/Network_layer" title="Network layer" class="wl">network layer</a> switching mode, where all data packets belonging to the same traffic stream are delivered over the same path, and traffic flows are identified by some connection identifier reducing the overhead of routing decisions on a packet-by-packet basis for the network.

Connection-oriented protocol services are often, but not always, <a href="/en/Reliability_(computer_networking)" title="Reliability (computer networking)" class="wl">reliable</a> network services that provide acknowledgment after successful delivery and <a href="/en/Automatic_repeat_request" title="Automatic repeat request" class="wl">automatic repeat request</a> functions in case of missing or corrupted data. <a href="/en/Asynchronous_Transfer_Mode" title="Asynchronous Transfer Mode" class="wl">Asynchronous Transfer Mode</a>, <a href="/en/Frame_Relay" title="Frame Relay" class="wl">Frame Relay</a> and <a href="/en/Multiprotocol_Label_Switching" title="Multiprotocol Label Switching" class="wl">MPLS</a> are examples of a connection-oriented, unreliable protocol.[<a href="/en/Wikipedia:Citation_needed" title="Wikipedia:Citation needed" class="wl">citation needed</a>] <a href="/en/SMTP" title="SMTP" class="mw-redirect wl">SMTP</a> is an example of a connection-oriented protocol in which if a message is not delivered, an error report is sent to the sender which makes SMTP a reliable protocol. Because they can keep track of a conversation, connection-oriented protocols are sometimes described as stateful.

Connection-oriented communication is a network communication mode in telecommunications and computer networking, where a communication session or a semi-permanent connection is established before any useful data can be transferred. The established connection ensures that data is delivered in the correct order to the upper communication layer. The alternative to connection-oriented transmission is connectionless communication, for example the datagram mode communication used by Internet Protocol and User Datagram Protocol, where data may be delivered out of order, since different network packets are routed independently and may be delivered over different paths. Connection-oriented communication may be implemented with a circuit switched connection, or a packet-mode virtual circuit connection. In the latter case, it may use either a transport layer virtual circuit protocol such as the TCP protocol, allowing data to be delivered in order. Although the lower-layer switching is connectionless, or it may be a data link layer or network layer switching mode, where all data packets belonging to the same traffic stream are delivered over the same path, and traffic flows are identified by some connection identifier reducing the overhead of routing decisions on a packet-by-packet basis for the network. Connection-oriented protocol services are often, but not always, reliable network services that provide acknowledgment after successful delivery and automatic repeat request functions in case of missing or corrupted data. Asynchronous Transfer Mode, Frame Relay and MPLS are examples of a connection-oriented, unreliable protocol. SMTP is an example of a connection-oriented protocol in which if a message is not delivered, an error report is sent to the sender which makes SMTP a reliable protocol. Because they can keep track of a conversation, connection-oriented protocols are sometimes described as stateful. 