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What is TCP/IP?TCP/IP stands for Transmission Control Protocol/Internet Protocol and is a suite of communication protocols used to interconnect network devices on the internet. TCP/IP is also used as a communications protocol in a private computer network (an intranet or extranet). The entire IP suite -- a set of rules and procedures -- is commonly referred to as TCP/IP. TCP and IP are the two main protocols, though others are included in the suite. The TCP/IP protocol suite functions as an abstraction layer between internet applications and the routing and switching fabric.
TCP/IP specifies how data is exchanged over the internet by providing end-to-end communications that identify how it should be broken into packets, addressed, transmitted, routed and received at the destination. TCP/IP requires little central management and is designed to make networks reliable with the ability to recover automatically from the failure of any device on the network. The two main protocols in the IP suite serve specific functions. TCP defines how applications can create channels of communication across a network. It also manages how a message is assembled into smaller packets before they are then transmitted over the internet and reassembled in the right order at the destination address. IP defines how to address and route each packet to make sure it reaches the right destination. Each gateway computer on the network checks this IP address to determine where to forward the message. A subnet mask tells a computer, or other network device, what portion of the IP address is used to represent the network and what part is used to represent hosts, or other computers, on the network. Network address translation (NAT) is the virtualization of IP addresses. NAT helps improve security and decrease the number of IP addresses an organization needs. Common TCP/IP protocols include the following:
How does TCP/IP work?TCP/IP uses the client-server model of communication in which a user or machine (a client) is provided a service, like sending a webpage, by another computer (a server) in the network. Collectively, the TCP/IP suite of protocols is classified as stateless, which means each client request is considered new because it is unrelated to previous requests. Being stateless frees up network paths so they can be used continuously. The transport layer itself, however, is stateful. It transmits a single message, and its connection remains in place until all the packets in a message have been received and reassembled at the destination. The TCP/IP model differs slightly from the seven-layer Open Systems Interconnection (OSI) networking model designed after it. The OSI reference model defines how applications can communicate over a network. Why is TCP/IP important?TCP/IP is nonproprietary and, as a result, is not controlled by any single company. Therefore, the IP suite can be modified easily. It is compatible with all operating systems (OSes), so it can communicate with any other system. The IP suite is also compatible with all types of computer hardware and networks. TCP/IP is highly scalable and, as a routable protocol, can determine the most efficient path through the network. It is widely used in current internet architecture. The 4 layers of the TCP/IP modelTCP/IP functionality is divided into four layers, each of which includes specific protocols:
Uses of TCP/IPTCP/IP can be used to provide remote login over the network for interactive file transfer to deliver email, to deliver webpages over the network and to remotely access a server host's file system. Most broadly, it is used to represent how information changes form as it travels over a network from the concrete physical layer to the abstract application layer. It details the basic protocols, or methods of communication, at each layer as information passes through. Pros and cons of TCP/IPThe advantages of using the TCP/IP model include the following:
The disadvantages of TCP/IP include the following:
How are TCP/IP and IP different?There are numerous differences between TCP/IP and IP. For example, IP is a low-level internet protocol that facilitates data communications over the internet. Its purpose is to deliver packets of data that consist of a header, which contains routing information, such as source and destination of the data, and the data payload itself. IP is limited by the amount of data that it can send. The maximum size of a single IP data packet, which contains both the header and the data, is between 20 and 24 bytes long. This means that longer strings of data must be broken into multiple data packets that must be independently sent and then reorganized into the correct order after they are sent. Since IP is strictly a data send/receive protocol, there is no built-in checking that verifies whether the data packets sent were actually received. In contrast to IP, TCP/IP is a higher-level smart communications protocol that can do more things. TCP/IP still uses IP as a means of transporting data packets, but it also connects computers, applications, webpages and web servers. TCP understands holistically the entire streams of data that these assets require in order to operate, and it makes sure the entire volume of data needed is sent the first time. TCP also runs checks that ensure the data is delivered. As it does its work, TCP can also control the size and flow rate of data. It ensures that networks are free of any congestion that could block the receipt of data. An example is an application that wants to send a large amount of data over the internet. If the application only used IP, the data would have to be broken into multiple IP packets. This would require multiple requests to send and receive data, since IP requests are issued per packet. With TCP, only a single request to send an entire data stream is needed; TCP handles the rest. Unlike IP, TCP can detect problems that arise in IP and request retransmission of any data packets that were lost. TCP can also reorganize packets so they get transmitted in the proper order -- and it can minimize network congestion. TCP/IP makes data transfers over the internet easier. TCP/IP model vs. OSI modelTCP/IP and OSI are the most widely used communication networking protocols. The main difference is that OSI is a conceptual model that is not practically used for communication. Rather, it defines how applications can communicate over a network. TCP/IP, on the other hand, is widely used to establish links and network interaction. The TCP/IP protocols lay out standards on which the internet was created, while the OSI model provides guidelines on how communication has to be done. Therefore, TCP/IP is a more practical model. The TCP/IP and OSI models have similarities and differences. The main similarity is in the way they are constructed as both use layers, although TCP/IP consists of just four layers, while the OSI model consists of the following seven layers:
The upper layer for both the TCP/IP model and the OSI model is the application layer. Although this layer performs the same tasks in each model, those tasks may vary depending on the data each receives. The functions performed in each model are also similar because each uses a network layer and transport layer to operate. The TCP/IP and OSI models are each mostly used to transmit data packets. Although they will do so by different means and by different paths, they will still reach their destinations. The similarities between the TCP/IP model and the OSI model include the following:
The differences between the TCP/IP model and the OSI model include the following:
The history of TCP/IPThe Defense Advanced Research Projects Agency, the research branch of the U.S. Department of Defense, created the TCP/IP model in the 1970s for use in ARPANET, a wide area network that preceded the internet. TCP/IP was originally designed for the Unix OS, and it has been built into all of the OSes that came after it. The TCP/IP model and its related protocols are now maintained by the Internet Engineering Task Force. This was last updated in July 2021 Continue Reading About TCP/IP
Dig Deeper on Network Infrastructure
Which layer in the Transmission Control Protocol is responsible for delivering data between two nodes?TCP/IP relies on the transport layer to effectively control communications between two hosts. When an IP communication session must begin or end, the transport layer is used to build this connection. Which layer in the TCP IP model is responsible for delivering?The Transport layer is the fourth layer of the TCP/IP model. It deals with data in the form of data segments. It mainly performs segmentation of the data received from the upper layers. It is responsible for transporting data and setting up communication between the application layer and the lower layers. What layer in the TCP model is responsible for defining a way to interpret signals so network devices can communicate?Data-Link Layer: While the physical layer is all about cabling, connectors and sending signals, the data link layer is responsible for defining a common way of interpreting these signals, so network devices can communicate. What is the transmission control layer?The Transmission Control Protocol (TCP) is a transport layer protocol, and the Internet Protocol (IP) is a network layer protocol. What layer in the Transmission Control Protocol Internet Protocol model is responsible for delivering data?Layer 4: The Transport Layer
The transport layer provides a total end-to-end solution for reliable communications. TCP/IP relies on the transport layer to effectively control communications between two hosts.
Which layer in the transmission control model is responsible for delivering data between two nodes?The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between nodes on a network segment across the physical layer.
Which layer in the TCP IP model is responsible for delivering?The Transport layer is the fourth layer of the TCP/IP model. It deals with data in the form of data segments. It mainly performs segmentation of the data received from the upper layers. It is responsible for transporting data and setting up communication between the application layer and the lower layers.
Which protocol is responsible for transmitting data?The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.
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