Definition of Local Area Network (LANs) and Types of Local Area Networks
Definition of Local Area Network (LAN)
LAN is short for Local Area Network which is a network where hardware and software can communicate with each other in a limited area. LAN can only cover a very limited area. for example, can only reach within one building.
Local Area Network or local computer network is a computer network that is limited to a small area. From the above understanding, it can be concluded that this LAN is only limited to an area/complex. Examples of LANs that we often encounter are computer networks in office building complexes, internet cafes, cafes, private homes, etc.
With this LAN Technology, we can share the data that we have stored in the sharing folder, besides that we can also use 1 printer together in one local computer network. In general, these LANs use IEEE 802.3 Ethernet technology with data transfer speeds of up to 1000 Megabits per second (Mbps) which are connected through switches and routers. But lately some local networks use 802.11b technology or commonly called Wi-Fi (Wireless Fidelity). This Wi-Fi is a wireless technology so that it is more practical to install than an Ethernet-based LAN.
Because we no longer need to bother pulling cables to connect one computer to another. Places that provide a LAN connection with Wi-fi technology are usually called hotspots. usually can find these hotspots in hotel complexes, cafes, campuses, amusement parks etc.
LAN components and working principles
There are 2 main components in a local computer network (LAN), namely nodes and links.
1. Node Node is a point that can produce input data or receive data or both. The nodes are computers that are connected to each other.
2. Link Link is a data/information transmission path between nodes. This link is a relationship between one node and another node in a network.
The working principle of a LAN depends on the pattern or topology. If the network uses a non-centralized pattern, then each computer connected to the network is called a host. However, if the network is centralized then there will be the terms servers and workstations. For more details, we can see the explanation below.
1. Server Server is a computer that serves to control the network. From this server computer, we can control, send data and receive data from workstation computers. If this LAN is connected to a modem, then on this server we can set the bandwidth that can be used by each workstation computer when accessing the internet. We can also block websites that we don’t want, such as those related to pornography, cybercrime, violence etc. Usually the data that is used together (shared), is stored in a folder located on the server computer. In addition, the devices that are used together usually also work on this server computer, such as printers, disks, etc.
2. Workstation This workstation is a computer system that is connected to a server. This workstation can be a number of computers connected to each other or it can also be in the form of a large computer such as a minicomputer system. Workstations in the form of a number of computers are sometimes called clients. These clients are connected to each other with the help of a hub or switch which is then connected again to the server computer. So that between client and client or between client and server can exchange data directly. After the server and workstation computers are connected to each other, a link (network) is formed. This link is the medium for exchanging data between computers. After all the nodes are connected to each other, a link is formed that unites each other. Besides that, Printers installed on the server computer can also be used by the client computer with the help of a hub. C. Advantages and disadvantages of LAN
Profit :
1. File exchange can be done easily
2. Can do network control
3. The process of backing up data is easier
4. Work more effectively
5. With the sharing facility, there is time and cost-efficiency.
Loss :
1. If one computer is infected with a virus, it has the potential to infect other computers on the network.
2. Potential for data theft by irresponsible parties.
LAN (Local Area Network) Topology:
Topology is the pattern/form of the relationship between nodes in a network. There are several types of topologies in a LAN including:
A. Mesh Topology (Point to point)
Computer topology Multi-computer mesh topology is a network that connects computers on a point-to-point basis. This means that all computers will be connected one by one without being disconnected. In this mesh topology, the network uses a pattern that is not centralized.
1. The advantages of Fault-tolerant (the ability of the system to continue working when there is a component failure) are enormous because of the large number of links with each node.
2. Disadvantages of expensive installation costs Installation takes a long time because it has to be one-on-one complex network management o difficult network troubleshooting.
B. Star Topology (Star Topology)
Star topology is a network that connects all computers with a concentrator in the form of a hub or switch. In this topology, the network uses a centralized pattern so that there are computers that function as servers and those that act as workstations.
Profit :
1. Easy installation
2. Low installation cost
3. Adding nodes can be done easily
4. Easy troubleshooting
5. If one of the cables breaks, the network can still work
6. Centralized management and ease of networking at scale.
Deficiency
1. If the switch or hub is damaged, the network will be completely paralyzed
C. Ring Topology (Ring Network)
Ring topology is a network that connects hosts to other hosts in a closed loop. Host is a computer connected to a network. This topology uses a network pattern that is not centralized.
Advantages :
1. Easy installation process
2. Low installation cost
3. Adding nodes can be done easily
4. Works well on small scale networks
Deficiency
1. If the cable is broken or damaged, the network is completely paralyzed
2. The troubleshooting process is quite difficult
3. Network management on a large scale is difficult
D. Bus Topology Bus Topology Bus Topology
is a network that uses a cable to connect all computers. So that all hosts are connected directly to the cable. This topology uses a network pattern that is not centralized.
Advantages
1. Easy installation process
2. Low installation cost
3. Adding nodes can be done easily
4. Works well on small scale networks
Deficiency
1. If the cable is broken or damaged, the network is completely paralyzed
2. The troubleshooting process is quite difficult
3. Network management on a large scale is difficult
E. Tree Topology (Tree Network)
Tree topology is a centralized computer network in which there are node levels. Where the node above can control the node below it, data that goes to the bottom node must pass through the top node first. Vice versa.
Advantages
1. Adding nodes can be done easily
2. Easy troubleshooting
3. If one of the cables breaks, the network can still work
4. Centralized management and ease of networking at scale.
5. Can form separate network groups.
6. If a switch is off, only the network that is on that switch is dead.
Deficiency
1. If the top switch dies, the network below it will die completely.