LAN and WAN

Local Area Network (LAN), and Wide Area Network (WAN)

Local Area Network (LAN): Local Area Network (LAN) is a computer network, which is limited to a small office, single building, multiple buildings inside a campus etc. Typically a Local Area Network (LAN) is a private network owned and maintained by a single organization.

Below image shows a small Local Area Network (LAN) connected together using a Network Switch.

Wide Area Network (WAN):

A Wide Area Network (WAN) spans over multiple geographic locations, which is composed of multiple LANs. It is nearly impossible for a small to medium organization (except Network Service Providers) to pull network cables between their two offices in two different countries located 1000s of kilometers away. Network Service Providers (also called as ISPs) provide the connectivity solutions for Wide Area Networks (WAN).

Below image shows two Local Area Networks (LANs), located at two different geographical locations connected via Internet to create a Wide Area Network (WAN). LAN 1 is located in Chennai, India and LAN 2 is located in Manila, Philippines. The aerial distance between Chennai and Manila is about 4,400 Kilometres. It is almost impossible for a small to medium business to draw cables between Chennai and Manila. We normally avail the services of an Internet Service Provider for connectivity between these two offices.

Differences between Local Area Networks (LANs) and Wide Area Network (WAN)

• A Local Area Network (LAN) is a private computer network that connects computers in small physical areas. Example: A small office, A Single building, Multiple buildings inside a campus etc. Wide Area Networks (WAN) is type of computer network to connect offices which are located in different geographical locations. Wide Area Network (WAN) depends mainly on Internet Service Providers (ISPs) for connection solutions.

• Local Area Network (LAN) has higher bandwidth rates. Current Local Area Networks (LANs) runs on bandwidths of 100 Mbps, 1 Gbps or 10 Gbps. Wide Area Networks (WAN) has lower bandwidth rates compared with Local Area Network (LAN). Current Wide Area Networks runs on bandwidths of 4 Mbps, 8 Mbps, 20 Mbps, 50 Mbps or 100 Mbps.

• Local Area Network (LAN) bandwidth rates are almost constant. Local Area Network (LAN) bandwidth rates are dependent on characteristics of the LAN technology in use (Normally FastEthernet or Gigabit Ethernet). Since most of Wide Area Networks (WAN) connectivity solutions are dependent on Internet Service Providers (ISPs), budget related constraints affect the quality of WAN.

• Most of the current Local Area Networks (LANs) use Ethernet as the LAN Standard (FastEthernet 100 Mbps, or Gigabit Ethernet 1/10 Gbps). WAN uses technologies like VPN (Virtual Private Network) over Internet, MPLS, FrameRelay, or Leased Lines as WAN connectivity solutions.

• Since Local Area Networks (LANs) are private networks, managed by dedicated local network administrators, Local Area Networks (LANs) are more reliable and secure than Wide Area Networks (WANs). Since Wide Area Networks (WANs) involve 3rd party service providers, WAN networks are less reliable and secure.

• Initial set-up costs for Local Area Networks (LANs) are low as the devices required to set up the networks are cheap. Initial set-up costs for Wide Area Networks (WANs) are high, because of the devices (Routers, Firewalls etc), cables and manpower required.

• Local Area Networks (LANs) running costs are less Wide Area Networks (WANs) running costs are high. Wide Area Networks (WANs) normally have recurring monthly cost as Service Provider access fees.

• Wide Area Networks (WANs) are more congested than Local Area Networks (LANs).

Chapter 1 :- Introduction to Computer Networking

Chapter 2 :- What is a Computer Network

Chapter 3 :- Why we need computer networks

Chapter 4 :- Client Operating Systems

Chapter 5 :- Common Network Application Software

Chapter 6 :- LAN and WAN

Chapter 7 :- CAN and MAN

Chapter 8 :- Peer-to-Peer networks and Client-Server networks

Chapter 9 :- Centralized and Distributed Computer Networks

Chapter 10 :- Internetworks, Internet, Intranet and Extranet

Chapter 11 :- What is a Network Protocol