Editing Transmission Control Protocol (section)

{{short description|Principal protocol used to stream data across an IP network}}
{{Use American English|date=February 2021}}

{{Infobox networking protocol
| title      = Transmission Control Protocol
| logo       = 
| logo alt   = 
| image      = 
| image alt  = 
| caption    = 
| is stack   = yes
| abbreviation = TCP
| purpose    = 
| developer  = [[Vint Cerf]] and [[Bob Kahn]]
| date       = {{start date and age|1974}}
| based on   = Transmission Control Program 
| influenced = 
| osilayer   = [[Transport layer]] (4)
| ports      = 
| rfcs       = {{IETF RFC|9293|plainlink=yes}}
| hardware   = 
}}

The '''Transmission Control Protocol''' ('''TCP''') is one of the main [[communications protocol|protocol]]s of the [[Internet protocol suite]]. It originated in the initial network implementation in which it complemented the [[Internet Protocol]] (IP). Therefore, the entire suite is commonly referred to as [[TCP/IP]]. TCP provides [[reliability (computer networking)|reliable]], ordered, and [[error detection and correction|error-checked]] delivery of a [[reliable byte stream|stream]] of [[octet (computing)|octets]] (bytes) between applications running on hosts communicating via an IP network. Major internet applications such as the [[World Wide Web]], email, [[remote administration]], and [[file transfer]] rely on TCP, which is part of the [[transport layer]] of the TCP/IP suite. [[Transport Layer Security|SSL/TLS]] often runs on top of TCP.

TCP is [[Connection-oriented communication|connection-oriented]], meaning that sender and receiver firstly need to establish a connection based on agreed parameters; they do this through three-way handshake procedure.<ref>{{Cite book |title=Location-Based Information Systems Developing Real-Time Tracking Applications |year=2010 |isbn=9781000556803 |last1=Labrador |first1=Miguel A. |last2=Perez |first2=Alfredo J. |last3=Wightman |first3=Pedro M. |publisher=CRC Press }}</ref> The server must be listening (passive open) for connection requests from clients before a connection is established. Three-way [[Handshake (computing)|handshake]] (active open), [[Retransmission (data networks)|retransmission]], and error detection adds to reliability but lengthens [[Network latency|latency]]. Applications that do not require reliable [[data stream]] service may use the [[User Datagram Protocol]] (UDP) instead, which provides a [[connectionless communication|connectionless]] [[datagram]] service that prioritizes time over reliability. TCP employs [[TCP congestion control|network congestion avoidance]]. However, there are vulnerabilities in TCP, including [[Denial-of-service attack|denial of service]], [[TCP sequence prediction attack|connection hijacking]], TCP veto, and [[TCP reset attack|reset attack]].

{{IPstack}}