You do not have permission to edit this page, for the following reasons:

This IP address has been blocked from editing Wikipedia.
This does not affect your ability to read Wikipedia pages.
Most people who see this message have done nothing wrong. Some kinds of blocks restrict editing from specific service providers or telecom companies in response to recent abuse or vandalism, and can sometimes affect other users who are unrelated to that abuse. Review the information below for assistance if you do not believe that you have done anything wrong.

The IP address or range 44.200.0.0/16 has been blocked (disabled) by ‪Blablubbs‬ for the following reason(s):

The IP address that you are currently using has been blocked because it is believed to be a web host provider or colocation provider. To prevent abuse, web hosts and colocation providers may be blocked from editing Wikipedia.
You will not be able to edit Wikipedia using a web host or colocation provider because it hides your IP address, much like a proxy or VPN.
We recommend that you attempt to use another connection to edit. For example, if you use a proxy or VPN to connect to the internet, turn it off when editing Wikipedia. If you edit using a mobile connection, try using a Wi-Fi connection, and vice versa. If you are using a corporate internet connection, switch to a different Wi-Fi network. If you have a Wikipedia account, please log in.
If you do not have any other way to edit Wikipedia, you will need to request an IP block exemption.

How to appeal if you are confident that your connection does not use a colocation provider's IP address:
If you are confident that you are not using a web host, you may appeal this block by adding the following text on your talk page: ((unblock|reason=Caught by a colocation web host block but this host or IP is not a web host. My IP address is _______. Place any further information here. ~~~~)). You must fill in the blank with your IP address for this block to be investigated. Your IP address can be determined here. Alternatively, if you wish to keep your IP address private you can use the unblock ticket request system. There are several reasons you might be editing using the IP address of a web host or colocation provider (such as if you are using VPN software or a business network); please use this method of appeal only if you think your IP address is in fact not a web host or colocation provider.

Administrators: The IP block exemption user right should only be applied to allow users to edit using web host in exceptional circumstances, and requests should usually be directed to the functionaries team via email. If you intend to give the IPBE user right, a CheckUser needs to take a look at the account. This can be requested most easily at SPI Quick Checkuser Requests. Unblocking an IP or IP range with this template is highly discouraged without at least contacting the blocking administrator.

This block will expire on 16:45, 10 February 2025.

Even when blocked, you will usually still be able to edit your user talk page, as well as email administrators and other editors.

For information on how to proceed, please read the FAQ for blocked users and the guideline on block appeals. The guide to appealing blocks may also be helpful.

Other useful links: Blocking policy · Help:I have been blocked
Your IP address is in a range that has been blocked on all Wikimedia Foundation wikis. The block was made by ‪AntiCompositeNumber‬. The reason given is Open proxy/Webhost: Visit the FAQ if you are affected .
- Start of block: 13:55, 18 August 2022
- Expiry of block: 13:55, 18 March 2025
Your current IP address is 44.200.254.7. The blocked range is 44.200.0.0/16. Please include all above details in any queries you make. If you believe you were blocked by mistake, you can find additional information and instructions in the No open proxies global policy. Otherwise, to discuss the block please post a request for review on Meta-Wiki. You could also send an email to the stewards VRT queue at stewards@wikimedia.org including all above details.

You can view and copy the source of this page:

((Use mdy dates|date=October 2019))
((more citations needed|date=June 2019))

In [[telecommunication]]s and [[computer networking]], '''connection-oriented communication''' is a [[communication protocol]] 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 is called ''[[connectionless communication]]'', such as the [[datagram]] mode communication used by [[Internet Protocol]] (IP) and [[User Datagram Protocol]] (UDP), where data may be delivered out of order, since different [[network packet]]s 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 [[Transmission Control Protocol]] (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, ''[[Reliability (computer networking)|reliable]]'' network services that provide acknowledgment after successful delivery and [[automatic repeat request]] functions in case of missing or corrupted data. [[Asynchronous Transfer Mode]] (ATM), [[Frame Relay]] and [[Multiprotocol Label Switching]] (MPLS) are examples of connection-oriented unreliable protocols.((Citation needed|reason=While ATM and frame relay are mentioned as unreliable in the linked Wikipedia article, no citation is available there and no info on MPLS's reliability is stated|date=April 2018)) [[Simple Mail Transfer 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, making it a reliable protocol. Because they can keep track of a conversation, connection-oriented protocols are sometimes described as stateful.

==Circuit switching==
[[Circuit switched]] communication, for example the [[public switched telephone network]], [[ISDN]], [[SONET/SDH]] and [[optical mesh network]]s, are intrinsically connection-oriented communications systems. Circuit-mode communication provides guarantees that constant bandwidth will be available and [[bit stream]] or [[byte stream]] data will arrive in order with constant delay. The switches are reconfigured during a circuit establishment phase.

==Virtual circuit switching==
[[Packet switched]] communication may also be connection-oriented, which is called [[virtual circuit]] mode communication. Due to the packet switching, the communication may suffer from variable bit rate and delay, due to varying traffic load and packet queue lengths. Connection-oriented communication does not necessarily imply [[Reliability (computer networking)|reliability]].

===Transport layer===
Connection-oriented [[transport layer]] protocols provide connection-oriented communications over connectionless communications systems. A connection-oriented transport layer protocol, such as [[transmission control protocol|TCP]], may be based on a connectionless network layer protocol (such as IP), but still achieves in-order delivery of a byte-stream, by means of segment sequence numbering on the sender side, packet buffering and data packet reordering on the receiver side.

===Datalink and network layer===
In a connection-oriented packet-switched [[data link layer|data-link]] or [[network layer|network-layer]] protocol, all data is sent over the same path during a communication session. Rather than using complete routing information for each packet (source and destination addresses) as in connectionless datagram switching such as conventional IP routers, a connection-oriented protocol identifies traffic flows only by a channel or data stream number, often denoted [[virtual circuit identifier]] (VCI). Routing information may be provided to the network nodes during the connection establishment phase, where the VCI is defined in tables in each node. Thus, the actual packet switching and data transfer can be taken care of by fast hardware, as opposed to slower software-based routing. Typically, this connection identifier is a small integer (for example, 10 bits for Frame Relay and 24 bits for ATM). This makes network switches substantially faster.

ATM and Frame Relay, for example, are both examples of connection-oriented, [[Reliability (computer networking)|unreliable]] data link layer protocols. Reliable connectionless protocols exist as well, for example [[AX.25]] network layer protocol when it passes data in I-frames, but this combination is rare, and reliable-connectionless is uncommon in modern networks. 
 
Some connection-oriented protocols have been designed or altered to accommodate both connection-oriented and connectionless data.<ref>((cite web |url=http://www.google.com/patents?id=hzKUAAAAEBAJ |title=US Patent Application Publication 2005/0117529 A1 |access-date=May 19, 2008 |author=Ramos-Escano |date=June 2, 2005|display-authors=etal))</ref>

==Examples==
Examples of connection-oriented packet-mode communication, i.e. virtual circuit mode communication: 
((div col|colwidth=20em))
* [[Asynchronous Transfer Mode]]
* [[Connection-oriented Ethernet]]
* [[Datagram Congestion Control Protocol]]
* [[Frame Relay]]
* [[General Packet Radio Service]]
* [[IPX/SPX]]
* [[Multiprotocol Label Switching]]
* [[Stream Control Transmission Protocol]]
* [[Transmission Control Protocol]]
* [[Transparent Inter-process Communication]]
* [[X.25]]
((div col end))

==References==
((reflist))

((DEFAULTSORT:Connection-oriented))
[[Category:Computer networking]]
[[Category:Internet architecture]]
[[Category:Internet protocols]]
[[Category:Network protocols]]

Pages transcluded onto the current version of this page (help):

Connection-oriented communication (edit)
Template:Ambox (view source) (template editor protected)
Template:Category handler (view source) (protected)
Template:Citation needed (view source) (protected)
Template:Cite web (view source) (protected)
Template:DMCA (view source) (template editor protected)
Template:Dated maintenance category (view source) (template editor protected)
Template:Dated maintenance category (articles) (view source) (template editor protected)
Template:Delink (view source) (protected)
Template:Div col (view source) (template editor protected)
Template:Div col/styles.css (view source) (template editor protected)
Template:Div col end (view source) (template editor protected)
Template:FULLROOTPAGENAME (view source) (template editor protected)
Template:Find sources mainspace (view source) (template editor protected)
Template:Fix (view source) (protected)
Template:Fix/category (view source) (protected)
Template:Main other (view source) (protected)
Template:More citations needed (view source) (template editor protected)
Template:Ns has subpages (view source) (protected)
Template:Reflist (view source) (protected)
Template:Reflist/styles.css (view source) (protected)
Template:Use mdy dates (view source) (template editor protected)
Module:Arguments (view source) (protected)
Module:Category handler (view source) (protected)
Module:Category handler/blacklist (view source) (protected)
Module:Category handler/config (view source) (protected)
Module:Category handler/data (view source) (protected)
Module:Category handler/shared (view source) (protected)
Module:Check for unknown parameters (view source) (protected)
Module:Citation/CS1 (view source) (protected)
Module:Citation/CS1/COinS (view source) (protected)
Module:Citation/CS1/Configuration (view source) (protected)
Module:Citation/CS1/Date validation (view source) (protected)
Module:Citation/CS1/Identifiers (view source) (protected)
Module:Citation/CS1/Utilities (view source) (protected)
Module:Citation/CS1/Whitelist (view source) (protected)
Module:Citation/CS1/styles.css (view source) (protected)
Module:Delink (view source) (protected)
Module:Find sources (view source) (template editor protected)
Module:Find sources/config (view source) (template editor protected)
Module:Find sources/links (view source) (template editor protected)
Module:Find sources/templates/Find sources mainspace (view source) (template editor protected)
Module:Message box (view source) (protected)
Module:Message box/ambox.css (view source) (protected)
Module:Message box/configuration (view source) (protected)
Module:Namespace detect/config (view source) (protected)
Module:Namespace detect/data (view source) (protected)
Module:Ns has subpages (view source) (protected)
Module:String (view source) (protected)
Module:Unsubst (view source) (protected)
Module:Yesno (view source) (protected)

Return to Connection-oriented communication.

Retrieved from "https://en.wikipedia.org/wiki/Connection-oriented_communication"