Question

Why Transmission Control Protocol (TCP) is called as Connection Oriented? Briefly explain

Answer 1

The Transmission Control Protocol/Internet Protocol (TCP/IP) is a popular network model created by the U.S. Defense Advanced Research Projects Agency in the 1970s.

Transmission Control Protocol (TCP) is a transport protocol that provides a mode connected service to the upper layers for example session, presentation and application. TCP is the Transmission Control Protocol, a reliable Layer 4 protocol that uses a three-way handshake to create reliable connections across a network. TCP provides reliable service and is therefore used in the end-to-end packet communication between two computers. TCP controls the transmitter flow in order not to exceed the capacity of the network and assures that this flow will not be too high relative to the receiver flow. TCP is a protocol which is responsible for reliable
communication between to Computer on the Network or WWW. TCP is a transport layer protocol. TCP handles packet flow between systems. TCP (Transmission Control Protocol) is a standard that defines how to establish and maintain a network conversation through which application programs can exchange data. TCP works with the Internet Protocol (IP), which defines how computers send packets of data to each other.

TCP is a connection oriented protocol. TCP is a connection-oriented protocol, which means a connection is established and maintained until the application programs at each end have finished exchanging messages. When a web server sends an HTML file to a client, it uses the hypertext transfer protocol (HTTP) to do so. The HTTP program layer asks the TCP layer to set up the connection and send the file. The TCP stack divides the file into data packets, numbers them and then forwards them individually to the IP layer for delivery. Although each packet in the transmission has the same source and destination IP address, packets may be sent along multiple routes. The TCP program layer in the client computer waits until all the packets have arrived then acknowledges those it receives and asks for the re-transmission of any it does not based on missing packet numbers. The TCP layer then assembles the packets into a file and delivers the file to the receiving application.

TCP is used for organizing data in a way that ensures the secure transmission between the server and client. It guarantees the integrity of data sent over the network, regardless of the amount. For this reason, it is used to transmit data from other higher-level protocols that require all transmitted data to arrive. Examples include:

v Simple Mail Transfer Protocol (SMTP), Post Office Protocol (POP), Internet Message Access Protocol (IMAP): For sending and receiving email.

v Secure Shell (SSH), File Transfer Protocol (FTP), Telnet: For peer-to-peer file sharing, and, in Telnet's case, logging into another user's computer to access a file.

v HTTP: For web access

These examples all exist at the application layer of the TCP/IP stack and send data downwards to TCP on the transport layer.

TCP is important because it establishes the rules and standard procedures for the way information is communicated over the internet. It is the foundation for the internet as it exists today and ensures that data transmission is carried out uniformly, regardless of the location, hardware or software involved. For this reason, it is flexible and highly scalable, meaning new protocols can be introduced to it and it will accommodate them.

The Network Access Layer of the TCP/IP model combines Layer 1 (Physical) and Layer 2 (Data Link) of the OSI model. It describes Layer 1 issues such as energy, bits, and the medium used to carry them (e.g., copper, fiber, wireless). It also describes Layer 2 issues such as converting bits into protocol units such as Ethernet frames, MAC addresses, and Network Interface Cards.

The Transmission Control Protocol (TCP) is a transport layer protocol that provides for a connection-oriented, reliable service to applications. A connection-oriented protocol establishes a connection, manages the data transfer, and terminates the connection. TCP offers full-duplex and multiplex service to applications.

These all are the reasons TCP is called connection oriented.