TCP/IP

Transmission Control Protocol/Internet Protocol (TCP/IP).

Communication protocols are the rules that computers use to communicate with each other and to transmit data. Transmission Control Protocol/Internet Protocol (TCP/IP) is used for:

• Email

• File transfer between computers

• Logging in remotely

Layers of TCP/IP:

This figure depicts the layers of the TCP/IP protocol. From the top they are, Application Layer, Transport Layer, Network Layer, Network Interface Layer, and Hardware.

Source: https://www.ibm.com/docs/en/aix/7.2?topic=protocol-tcpip-protocols

TCP/IP carefully defines how information moves from sender to receiver. First, application programs send messages or streams of data to one of the Internet Transport Layer Protocols, either the User Datagram Protocol (UDP) or the Transmission Control Protocol (TCP). These protocols receive the data from the application, divide it into smaller pieces called packets, add a destination address, and then pass the packets along to the next protocol layer, the Internet Network layer.

The Internet Network layer encloses the packet in an Internet Protocol (IP) datagram, puts in the datagram header and trailer, decides where to send the datagram (either directly to a destination or else to a gateway), and passes the datagram on to the Network Interface layer.

The Network Interface layer accepts IP datagrams and transmits them as frames over a specific network hardware, such as Ethernet or Token-Ring networks.

Source: https://www.ibm.com/docs/en/aix/7.2?topic=protocol-tcpip-protocols