TCP/IP is a suite of protocols that are used to transmit data over the internet. It is the primary protocol used to transmit data over the internet, and is used by billions of devices around the world to connect to the internet and communicate with each other.
One of the key features of TCP/IP is its hierarchical structure. It is made up of many different protocols that are organized into four layers: the network interface layer, the internet layer, the transport layer, and the application layer. Each layer serves a specific purpose and communicates with the layers above and below it using a set of standardized interfaces.
| Layer | Protocol |
| Application | NFS, NIS+, DNS, telnet, ftp, rlogin, rsh, rcp, RIP, RDISC, SNMP, and others |
| Transport | TCP, UDP |
| Internet | IP, ARP, ICMP |
| Network Access | Ethernet (IEEE 802.3) Token Ring, RS-232, PPP, IEEE 802.2 |
TCP/IP Layers
Network access layer: Also called Network Interface Layer. This layer is responsible for transmitting data between devices using a specific type of physical connection, such as Ethernet or Wi-Fi. It is the lowest layer of the TCP/IP stack, and is responsible for physically sending and receiving data.
Internet layer: This layer is responsible for routing data packets between devices. It includes the IP (Internet Protocol) protocol, which is responsible for dividing data into packets, assigning each packet a unique identifier and a destination address, and sending the packets over the network to their destination.
Transport layer: This layer is responsible for establishing and maintaining connections between devices, and for ensuring the reliable transmission of data. It includes the TCP (Transmission Control Protocol) protocol, which is responsible for establishing and maintaining connections, as well as the UDP (User Datagram Protocol) protocol, which is used for real-time applications that require low latency.
Application layer: This layer is the highest layer of the TCP/IP stack, and is responsible for providing services to applications. It includes a number of protocols, such as HTTP (Hypertext Transfer Protocol), which is used to transfer data between web servers and clients, and SMTP (Simple Mail Transfer Protocol), which is used to transmit email messages.
One of the unique features of TCP/IP is its ability to work with a wide range of hardware and software platforms. It is a universal protocol that is used by devices of all types and sizes, from smartphones and laptops to servers and mainframes. This versatility has made TCP/IP the dominant protocol for transmitting data over the internet and has contributed to the rapid growth and success of the internet.