It is clear that networks provide benefits over using single machines by sharing resources, having secure connection, remote control, etc. Network equipment can be divided in three main parts that are necessary for successful network operation.
First part is the equipment, located at the end of the lines. It includes client, server, workstation. You can read more about Client Server Definition here. Workstation is a computer/phone/tablet that may or may not be a part of the network.
Client is a workstation connected to the network and using it to access different clients/servers/services. Word “client” sometimes also mean the human user or specialized software installed on the workstation. Server is a special computer with the purpose of sharing resources in the network. It has greater computational power, larger memory and hard disk space. It usually runs special version of OS that is designed for data, user and security management purposes. It has variety of built-in networking functions and applications.
Most common versions of server OS are Linux and UNIX based solutions, as well as MAC OS Server and Microsoft Windows Server. This software is specially designed for servers, and are typically useless for normal workstations. Both server and workstation would require networking interface card that is being installed additionally or as part of the motherboard of the computer/server. This card allows communication between devices using network. External network cards also exist, but they are not very popular for stationary workstations/servers.
Second part of the network is connectivity equipment. Main part of the equipment is the host – a computer that enables sharing, user policy, security in the network. Usually server is playing a role of the host.
Another piece of equipment is being called node. Nodes are workstations, servers and other equipment that have unique IDs in the network also called network address (more about that later in article).
Part of the LAN which is connected through one switch/router/splitter is being called a segment of the network. Equipment used for connecting devices together (switch/router/splitter, EPON network) is referred as connecting devices. When two segments are being connected, the connection between them is called backbone.
Figure 1. Simple LAN example.
Lets see the example as shown in Figure 1: The newspaper company is located in a skyscraper in center of Paris. Sports news office is located on the seventh floor of the building. It has many workstations and a server that are connected together through a switch (connectivity device A). Meanwhile, there is a weather news office on the eighth floor, where are couple workstations interconnected through the switch (connectivity device B). Both A and B with connected to them nodes are forming two segments of the network. Both switches are having backbone connection going to the main switch on the ninth floor where is the buildings server room.
Essential part of the network is the network is the transmission media it can be physical like wires and cables or wireless – using radio waves as shown in Figure 2.
Figure 2. Examples of network transmission media.
We should not forget that network equipment may be connected using different topology – way of connection. It can be a ring, bus or star topology (or combination of them), although star is the most common. For example most popular Fiber To Home networks, based on FTTx EPON accesstechnology, uses a star approach.
Final part of the network is not physical. Virtual unique IDs, also called network addresses for every node in the network, that would simplify communication between devices. How the addresses are being assigned depends on the network protocols and server OSs. Network protocols are network communication standards that are supported by most modern networking equipment. Different protocols are serving different purposes – there are security protocols, data integrity protocols, web protocols, etc.
All this is made for purpose of data exchange in the network. Data is not transmitted in one stream, but it is sent in packets – small units of data. Breaking data in packets makes delivery on the network more efficient and reliable.
