Transmission Control Protocol (TCP) and Internet protocol (IP)

Among the computer network protocols, there are two distinct protocols namely transmission control protocol (TCP) and Internet protocol (IP). TCP is a standard that defines how to establish and maintain a network conversation via which application programs can exchange data[1]. On the other hand, IP stands for "Internet Protocol." IP provides a standard set of rules for sending and receiving data over the Internet. It allows devices running on different platforms to communicate with each other as long as they are connected to the Internet[2]. TCP/IP functionality is divided into four layers, each with its own set of agreed-upon protocols[3]:

1. The datalink layer consists of methods and protocols that operate only on a link, which is the network component that interconnects nodes or hosts in the network. Protocols in the layer include Ethernet and ARP (Address Resolution Protocol).


2. The internet (or networking) layer connects independent networks to transport the packets containing the data across network boundaries. Protocols are IP and ICMP (Internet Control Message Protocol).


3. The transport layer handles communications between hosts and is responsible for flow control, reliability, and multiplexing. Protocols include TCP and UDP (User Datagram Protocol).


4. The application layer standardizes data exchange for applications. Protocols include HTTP, FTP, POP3, SMTP, and SNMP (respectively, HyperText Transfer Protocol, File Transfer Protocol, Post Office Protocol Version 3, Simple Mail Transfer Protocol, and Simple Network Time Protocol).

Transmission Control Protocol accepts data from a data stream, divides it into chunks, and adds a TCP header creating a TCP segment. The TCP segment is then encapsulated into an Internet Protocol (IP) datagram, and exchanged with peers. A TCP segment consists of a segment header and a data section. The segment header contains 10 mandatory fields, and an optional extension field (Options, pink background in table). The data section follows the header and is the payload data carried for the application. The length of the data section is not specified in the segment header; It can be calculated by subtracting the combined length of the segment header and IP header from the total IP datagram length specified in the IP header.

TCP/IP has always been considered a very heavy protocol, requiring a lot of memory and hardware to use. With the development of graphical interfaces, the evolution of processors, and the effort of operating system developers to provide TCP/IP for their platforms with performance equal to or sometimes superior to other protocols. TCP/IP offers some benefits, including:

Standardization: A standard, routable protocol that is the most complete and accepted protocol available today. All modern operating systems support TCP / IP, and most large networks rely on TCP/IP for most of their traffic.

Interconnectivity: A technology for connecting non-similar systems. Many standard connectivity utilities are available to access and transfer data between these non-similar systems, including File Transfer Protocol (FTP) and Terminal Emulation Protocol (Telnet).

Routing: Enables and enables older and newer technologies to connect to the Internet. It works with line protocols such as P2P (Point to Point Protocol) allowing remote connection from dial-up or dedicated line. It works as the IPCs mechanisms and interfaces most used by operating systems, such as Windows sockets and NetBIOS.

Robust Protocol: scalable, multiplatform, with structure to be used in client/server operating systems, allowing the use of applications of this size between two distant points.

Internet: It is through the TCP/IP protocol suite that we gain access to the Internet. Local area networks distribute Internet access servers (proxy servers) and local hosts connect to these servers for Internet access. This access can only be achieved if the computers are configured to use TCP/IP.

 

References:

[1]      “What is TCP (Transmission Control Protocol)? - Definition from WhatIs.com,” 2014. [Online]. Available: https://searchnetworking.techtarget.com/definition/TCP. [Accessed: 10-Oct-2019].

[2]      “IP (Internet Protocol) Definition,” techterms.com, 2016. [Online]. Available: https://techterms.com/definition/ip. [Accessed: 10-Oct-2019].

[3]      B. Mitchell, “TCP/IP in Computer Networking,” 2019. [Online]. Available: https://www.lifewire.com/transmission-control-protocol-and-internet-protocol-816255. [Accessed: 10-Oct-2019].