LAN is a type of network which is used to connect devices within a limited area. LAN is limited to a building, church, school, or small geographical area. Ethernet and power over the Ethernet are the most popular LAN technologies used today. Cost efficiency, Installed base, Maintainability, and Performance are factors considered while selecting the LAN. WAN is used to connect devices over a large geographical area such as within a country or a continent.
Introduction
- A data communication network that allows the connection of various terminals or computers within a building or limited geographical area is known as a Local Area Network(LAN).
- Devices in the network are connected through a wireless or wired connection.
- Some examples of standard LAN technologies are Ethernet, Token Ring, and Wireless LAN using IEEE 802.11, etc
- A LAN is exclusive to an organization, such as an office, school, church, or association.
History of LAN
1973: The Birth date of Ethernet
The Ethernet was invented by Dr Robert M. Metcalfe in 1973. Its job was to connect all the computers in a building to each other so that they can communicate with each other and also connect these computers to the world’s first Xerox laser printer. In a memo, the networking method was named “Ethernet” because a large amount of coaxial cable was required to connect the computers. The ARPANET was informed about the idea of Metcalfe’s. The U.S. Department of Defense developed the original ethernet— and the University of Hawaii developed ALOHAnet which was a packet-switching wireless radio network for computers. Using Ethernet computers are allowed to transmit data through a coaxial cable so that they can communicate with each other and also with printers. It implied a collision-detection scheme. In case, if network nodes are fired simultaneously, then it causes a collision, the mainframe stop responding and to fire again nodes are required to wait for random milliseconds.
1977: The first commercial LAN
After four years, the first commercial LAN was installed by Datapoint Corpat at Chase Manhattan Bank in New York. Unlike Metcalfe’s Ethernet, the Attached Resource Computer (ARC) network was used by Datapoint’s LAN. When the Ethernet applies collision detection, then the ARC implies a scheme known as a token-passing scheme so that they can easily escape the synchronous transmission of data by nodes. We can also say that the nodes took turns transferring signals rather than relying on random re-transferring.
1979: Ethernet now available to the public
For developing and selling Ethernet products, Metcalfe now began 3Com.
1985: IEEE becomes the standard for LAN
Around 1985, Ethernet became the Institute of Electrical and Electronics Engineers (IEEE) standard for LAN.
1990: Ethernet wins over LAN
The battle that was against the LAN was won by the ethernet, in part by switching to a twisted pair cable, which decreases electromagnetic induction and crosstalk. In other words, Ethernet was faster.
1991: Work begins on wireless LAN
The IEEE started working on wireless LAN (WLAN), which is based on the ALOHAnet prototype.
1997: Wi-Fi is born
802.11 (Wi-Fi) standard is a Wi-Fi standard that was released by IEEE. Wi-Fi standard uses a wait-and-see carrier sense multiple access/collision avoidance (CSMA/CA) scheme in place of collision detection. For a random time, radio waves broadcasted by LAN are listened to by a Wi-Fi device, and when if founds network is idle then it sends the signal in the form of a frame. The receiver sends an acknowledgement(ACK) after receiving the frame. Wireless LANs (WLANs) and LANs use the gateway for accessing the internet or wide area networks (WANs).
Types of LAN
Client-Server LAN
In a client-server LAN, there is only one server and with this server, multiple devices are connected and these devices are known as clients. Client devices are not allowed to interact with each other. They are only allowed to communicate with a server. A centralized machine handles all the activities like network access control, network traffic management, etc. This LAN-type performance is good in small perimeters, but in a large area, it places too much burden on the central server.
Peer-to-peer (P2P) LAN
There is no centralized server in P2P LAN all connected devices can interact with each other, regardless of whether they are servers or clients. The main advantage of using a P2P LAN is that devices can freely exchange data with one another, making it easier to send files, and stream media, and can also perform similar data exchange activities. On the other side, they are less powerful than client-server LANs.
Token ring LAN
Based on the design of architecture, LAN is divided into the token ring and token bus categories. All devices that are connected are arranged in the form of a ring. Every device connected to the ring is assigned a token based on its need.
Token bus LAN
Connected nodes are arranged in a tree-like structure in a token bus LAN and tokens can be sent either on the left side or right side. In a comparison of token ring LAN environments, it provides better bandwidth capacities.
Wired LAN
Probably the most common type of LAN used today is Wired LAN. Data is transferred using electronic waves across optical fiber (or cable variants) in place of tokens. A wired LAN can be very fast and extremely reliable depending on the performance of the central server. However, portability and flexibility can be obstructed in this type of LAN, especially in environments where is no fixed number of devices.
Wireless LAN
In-home type environments, where there is a need to connect computing devices, smart appliances, wearables, etc. use wireless networks. In this type of LAN, data is sent using radiofrequency which can make it sensitive to security risks also. It is also considered battery-intensive and sometimes shows fluctuating performance and it depends on the position of the wireless device.
Cloud-managed LAN
Cloud-managed LAN is considered a special type of wireless LAN. In this type of LAN, a centralized cloud platform is responsible for the management of network provisioning, policy enforcement, access control, security, and other aspects of network performance.
Factors While Selecting a LAN Technology
Cost Efficiency
Cost efficiency is one of the most important factors that must be considered while selecting LAN technology. Generally, it was considered that faster technology is more expensive but this was not universally true.
Installed Base
The installed base is considered another important factor in cost-effectiveness. There are very less chances that you are using scratch for building a new network. Generally, there are existing applications, existing equipment, servers, and a cable plant. There is an availability of alternative network technology which is cheaper. If you are switching to that then you require a very high cost for changing your installed base. So in this situation staying with existing technology may be considered more cost-effective.
Maintainability
Maintenance is considered the one of biggest hidden network costs. Generally, your design targets are centered toward reliability, the reliability is reduced as you cut more corners. Lower reliability is usually converted into very high maintenance costs for the network.
Performance
Everyone tries to put their efforts into building the fastest and best network. Here best means the network that will fulfill the need of the business. If the network does not support the application for which it was built but has unbelievable throughput and low latency then that network becomes useless.
Popular LAN Technologies Used Today
Ethernet
It was one of the most popular technology among all LAN technologies. It is the technology that is covered under IEEE standard 802.3. Its features such as low-cost investment, backward compatibility, noise resistance, etc make it a popular choice over other LAN technology. Ethernet will work on layer 1 and layer 2 of the OSI(Open System Interconnection) model. Ethernet has evolved significantly in the last few years.
TYPES OF ETHERNET
Following are the types of the ethernet
- 10 Mbit/s: It is considered the first iteration of Ethernet technology which was introduced in 1983.
- Fast Ethernet: This is a type of ethernet that carries 100 Mbits/ s and it was introduced in 1995. IEEE 802.3u standard covers this ethernet
- Gigabit Ethernet: This ethernet was introduced in 1999 and it was designed to carry one gigabit or one million bits per second. This was developed for meeting the requirement of increasing the speed of voice over IP (VoIP). VoIP is the technology that allows you to convert your voice into a form of digital signal that enables you to make a call directly from the computer.
- 10 Gigabit Ethernet: Gigabyte internet carries 10 gigabits per second and it was considered one of the most recent standards of Ethernet it is faster than gigabit ethernet and it uses fiber optic cable
ADVANTAGES OF ETHERNET
- Requires low-cost investment
- The main advantage of ethernet is noise resistance.
Power Over Ethernet
This standard allows the transmission of electric power and data via the same cable. Power over Ethernet is usually called PoE, which is mostly used to connect devices such as phones enabled with VoIP(Voice over IP) or internet protocol (IP) cameras. This standard makes use of ethernet cable 5 or higher categories. And it does not need any external adaptor or AC cord.
Types of power over ethernet
- Token Ring: IBM developed the token technology and this technology is used to connect computers with the help of three-byte frames and three-byte frames known as tokens. And these tokens travel in a network from servers or computers in a form of a logical ring structure. Token ring is designed to carry the data at the rate of 4, 16, and 100 Mbps
- Asynchronous Transfer Mode (ATM): ATM is a fast communication technique and it is one of the cell-based techniques. And ITU AND ANSI define telecommunication as standard. This technology is used for the transmission of signals among the devices connected to a network. One of the major advantages of using an ATM is that for transferring signals it does not require any separate overlay network
- ARCNET: Attached Resource Computer NETwork is abbreviated as ARCNET and this is a technology that was used for the connection of microcomputers in 1980. The main purpose of using this technology is to perform automation tasks in offices.
- FDDI: FDDI stands for Fibre Distributed Data Interface. FDDI is a LAN technology that makes use of fiber optic cables and is designed to carry data up to 100 MBit per second. It can transmit data up to 200 km and uses two rings for the transmission of data. The first ring is used for the primary backup and the second rank is used for the secondary backup
ADVANTAGES OF POWER OVER ETHERNET
- Allows transmitting electric power and data with the help of the same cable.
- It does not require any external adaptor or AC cord
LAN Example: Components Necessary for a LAN Connection
Computers with Interface Cards
Now a network interface card (NIC) comes with almost all modern PCs, tablets and laptops, etc. The NIC is provided with the driver software such that the operating system automatically updates and configures the NIC.
Public internet
The public internet is a centralized server that receives the packet of data from the public internet and can also access the requests from the client side. Then, respond to these requests by providing the data services to different nodes connected wired or wirelessly.
Cables
Unshielded Twisted Pair (UTP) cables are considered the standard. If your requirement is fast speed, then fiber optic cables are the best but it is expensive.
Switches and Hubs
LAN can use both hubs and switches. Hub first divides and then shares the data packet with all the nodes connected on the LAN whereas Switch allows the transmission of a dedicated packet to a single node only and also reduces traffic on the network.
Wired end-user devices
Generally, Wired end-user devices experienced high-quality media streaming, high-speed internet connectivity, and fast processing as compared to others. Some of the end-user devices are smart monitors, laptops, desktops, smart television, meeting room systems, etc.
Mobile end-user devices
Devices that you connect with the help of Wi-Fi in place of ethernet are known as Mobile end-user devices. Some of the mobile end-user devices are Smart home appliances, Wearables smart building components, smartphones, laptops, etc.
Centralized server
The most important component in the LAN environment is the Centralized Server. There are different vendors like Cisco, HPE, IBM, etc from where enterprises can lease or purchase the server.
Routers
Routers provide you with the facility to connect with other LANs and for this, they assign a specific IP address to the device to that you want to connect. Computers with Wi-Fi NICs can also be connected and also with the internet with the help of a wireless router.
Modem
The modem provides the facility of signal conversion and reversion so that a LAN can connect with other LANs and to the internet and they can form a WAN.
Software
Now the operating system of your choice comes with network software but still, you have to download some software for security purposes.
Dynamic Host Configuration Protocol (DHCP) Server
A computer with plenty of space on the hard drive and RAM is required to serve as a DHCP server. A DHCP server automatically assigns IP addresses to computers and devices connected to the local network.
Firewall Appliance (optional)
A firewall’s main job is to protect server and end-user devices from network-related security attacks and this firewall restrict the various type of traffic on the network. Now there is a built-in firewall software in mostly all end-user devices. Today, most end-user devices ship with a built-in firewall. You can also use a hardware firewall between the router and network switch or central server and switch so that it can restrict all the traffic coming to that network.
Difference Between LAN and WAN
LAN stands for local area network and is used to connect devices within a limited area such as a building or office. LAN network is also used to connect computers and printers within a home. WAN stands for wide area network and is used to connect the devices geographically such as among the continent or a country. WAN can also be considered as a series of LANs connected.
LAN vs Wi-Fi
Today if someone asks you if you require LAN ethernet or a Wi-Fi connection is just like a similar question of asking whether your requirement is consistency or convenience. Gigabit Ethernet is designed to transmit data at the speed of 1000 Mbps and fast internet can transmit data at the speed of 100 Mbps. In comparison to Ethernet the new Wi-Fi standards work as given below:
- 802.11ah: This is a standard that works on a frequency bandwidth lower than one gigahertz this means it can transmit data for longer distances in comparison to other standards. 347 Mbps is considered the top speed of this standard.
- 802.11ad: This is a Wi-Fi standard that works on a bandwidth of 60 gigahertz and it can transmit up to 6.7 Gbps it was very fast but the main limitation of this standard is that it can be operated up to 11 feet from the axis hub.
- 802.1ac (Wi-Fi 5): This is a Wi-Fi standard that works on the bandwidth of 5 gigahertz or 2.4 gigahertz. Its bandwidth is dependent on the router and it can transmit data up to 3.46 Gbps.
Best Practices for Implementing and Managing LAN
Enable WPA3 Encryption
In Wi-Fi security, WPA2 encryption serves as the global standard. WPA3 improves WPA2 in terms of providing more secure public Wi-Fi, addressing password-related vulnerabilities, etc. Using WPA3 it is easier to configure a secure Wi-Fi network.
Conduct LAN Inventory and Implement Standardization
The average LAN consists of eight key components and this key number can be increased according to the requirement of time. Whenever your network environment starts evolving then there is a chance of increasing clutter. Clutter is responsible for making the LAN difficult to handle, it becomes expensive to maintain and increases the chances of security threats also. For this purpose, you required a collection of network policies and hardware versions, and need to conduct a deep inventory so that can implement governance.
Deploy Network Redundancy as a Failsafe for LAN downtime
For making a reliable Local Area Network, redundancy is a necessary feature. Some factors can disrupt the connection in LAN. Some of these are central server configuration problems, wear and tear, security threats, weather-related issues, etc. For resolving this issue, an intermediate router can be used. This router in case of any disruption enables an automatic failover to various lines.
Carefully Consider the Physical LAN Design
Several LAN vendors nowadays promise plug-and-play LAN services to their customers, For every scenario this maybe not be the best fit. For business use, every organization requires a local area network that is designed according to their particular needs. The physical design of the LAN architecture of an organization includes the exact position of the routers and the exact number of network switches and their exact configuration and there must be the quality of cables that will be used.
Plan for the Internet of Things (IoT)
To connect IOT devices two types of networks can be used first one is low power wide area networks(LPWAN) for long ranges and the second one is wireless LAN which can be used when you want to connect within the same building or connect up to 100 meters. Depending upon your edge radius you can also use the dedicated network resource with the help of LAN or LPWAN. Consider managed LAN services to reduce in-house efforts if LAN services are properly managed then it was able to offload the governance, maintenance, and security aspects of managing the LAN. Mainly every major telecom career globally provides the service of managed LAN to their enterprise clients.
Adopt LAN Segmentation to Improve Performance
To improve the performance and to ensure more security segmentation enables to branch the local area network. Different LAN segments are not allowed to access each other.
Use a Physical Firewall Appliance in Addition to Firewall Software
Due to firewall software ubiquity, sometimes small businessmen and consumers make the small mistake of not doing an investment in additional firewall software. This is a fact that software alonely is not able to block 100% risks and vulnerabilities of the network. If the firewall was in the same system as the other applications if in some situations the devices are infected then firewall software will also stop working. So that’s why additional firewall software is required for enforcing restrictions and regulating traffic coming from the external nodes.
Assign LAN Implementation Ownership to Designated Stakeholders
LAN can be considered a core infrastructure pillar of the enterprise. And it cannot be bundled with the rest of the IT services or other network administrative duties of the enterprise. For controlling LAN implementation there must be a designated project manager that may belong to your internal team.
Conclusion
- LAN is a type of network in which all the devices are connected in a limited area.
- Some of the categories of LAN are peer-to-peer LAN, token bus LAN, client-server LAN, etc.
- Standard LAN technologies are Ethernet, and power over the Ethernet.
- Cost efficiency, Installed base, Maintainability, and Performance are factors considered while selecting the LAN.
