As we all know, serial to Ethernet converters is a data communication device by converting a serial port into a TCP/IP network interface. So what is TCP/IP?
While TCP/IP communication (and the collection of data from TCP/IP devices) may seem daunting at first glance, it is actually a very simple communication tool.
TCP/IP stands for Transmission Control Protocol/ Internet Protocol. Basically, it is a network protocol that defines the details of how data is sent and received through network adapters, hubs, switches, industrial routers, and other network communication hardware. Its aim is to connect government computer systems to each other through a global fault-tolerant network. The Ministry of Defense network was opened to research institutions, and eventually to the public, to create what is now the Internet. The TCP/IP protocol is also in the public domain, so any software company can develop network software based on it, since it is the main protocol used on the Internet and is in the public domain.
The TCP/IP protocol is designed so that each computer or device in the network has a unique IP address (Internet protocol address), and each IP address can be opened and communicated through up to 65,535 different ports for sending and receiving data. An IP address uniquely identifies a computer or device on the network, and a port number identifies a specific connection between one computer or device and another computer or device (that is, between two IP addresses). A TCP/IP port can be thought as a dedicated two-way communication line, where the port number is used to identify the unique connection between two devices.
Protocols of the TCP/IP model have significant advantages: they run independently of the hardware and underlying software. These protocols are standardized and can be used in any situation, regardless of the operating system used or the devices used to communicate over the network.
Protocols include layers 3 and 4 of the OSI model. The transport and link layers are directly responsible for connecting the two devices in the network. For example, IP addresses and Internet protocols are used to send packets to the right recipients. TCP, on the other hand, is responsible for establishing a connection between two devices and maintaining that connection for data transfer. If the transmission of packet fails, the protocol will try to resend the packet.
Since TCP/IP is just a general term for the most important Internet protocols, the term is also used in other instances. This is why there is also a reference model that controls TCP/IP. Similar to the OSI model, this model aims to map all aspects of network communication. However, the TCP/IP model consists of four different layers, while the OSI model has seven layers. The layers in the TCP/IP model are assigned various tasks, and hence the protocols.
● Network Access Layer: This layer is included in the reference model, but no specific protocol is defined. Actually, the Ethernet (wired) and IEEE 802.11(wireless) protocols are used primarily. The network access layer is used to link different subnets for applications, such as connecting a home Wi-Fi network to the Internet through a router.
● Internet Layer: The Internet protocol runs on this layer and ensures that the transmitted data reaches the correct destination. Packets are routed over the network via IP addresses.
● Transport Layer: TCP is used for transport in the reference model. The protocol allows end-to-end communication, which means that it is responsible for the connection between the two devices. Along with TCP, UDP is also a part of this layer.
● Application Layer: The top layer controls the communication between applications throughout the network. Protocols such as HTTP and FTP are critical to the application layer. E-mail communication protocols, such as POP or SMTP, also run on this layer.
A TCP/IP connection works like a telephone call, in which someone has to make a call to initiate a connection. At the other end of the connection, someone must listen for calls and then answer the phone when they come in. In TCP/IP communication, the IP address is similar to a phone number, and the port number is similar to a specific extension after a phone number answers a call. In a TCP/IP connection, the "client" is the computer or device that "dials", and the "server" is the computer that "listens" for incoming calls. In other words, the client needs to know the IP address of any server to which it wants to connect after the connection is established, and also the port number through which it wants to send and receive data.
Once a connection is established between the TCP/IP client and the TCP/IP server through the TCP/IP port, data can be sent in either direction (serial, parallel, etc.) in exactly the same way as it would be sent over any other type of port on the PC. The only difference is that the data is sent over the network. The connection between the client and the server remains open until the client or server terminates the connection (that is, hangs up the phone). One of the great benefits of the TCP/IP protocol is that it enables low-level drivers for sending and receiving data, and performs error checking on all data, so you can be sure that nothing you send or receive will go wrong.