A network can be classified on the basis of its area of distribution and the number of computers that are part of the network.
On the basis of its area of distribution, network is divided into following four parts:
- LAN (Local Area Network)
- MAN (Metropolitan Area Network)
- WAN (Wide Area Network)
- PAN (Personal Area Network)
LAN- LAN stands for local area network. It covers a small geographical area, usually within an office building or home. The maximum speed of LAN can be 1000 Mbps. It uses guided media or bounded media such as twisted cable, coaxial cable, optical fibre cable. LAN is a secure network and it is cost-effective. It is used for colleges, schools, hospitals and offices.
Advantages of local area network (LAN)
MAN- MAN stands for metropolitan area network. MAN cover a wider geographical area up to 50 Km diameter. Speed of MAN ranging from 2 Mbps to 300 Mbps. It uses guided (twisted cable, coaxial cable, optical fibre cable) or unguided (microwave, radiowave, infrared, laser) media for transmission. It is more expensive as compared to LAN. It is not secure.
- Data Sharing- All the data from the attached computers can be stored in one server. If any computer (Client) needs data then that computer user can simply access the data from the server.
- Data Security- Keeping data on the server is more secure. On the server, we can restrict data access to specific users so that only authorized users can access the data in the network.
- Sharing of resources- If any computer needs any resources such as DVD drive, printer, scanner and hard drive then it can be shared with the required computer using network.
- Internet Sharing- We can share one internet connection among all attached computers using the network, in which main internet cable is attached to one server and distributed among connected computers.
- Data security problem- If the server computer is not set up correctly and there is a leak in security then unauthorized users can access the data also.
- Server crashes may affect all computers- If any file on the server is corrupted or hard drive fails then all the attached computers face problems in functioning properly.
- Setting up a LAN is expensive- It is expensive to set up LAN because there is special software required to make a server. Also, communication devices like hubs, switches, routers, cables are costly and a special administrator is required to maintain and troubleshoot LAN for a large office.
MAN- MAN stands for metropolitan area network. MAN cover a wider geographical area up to 50 Km diameter. Speed of MAN ranging from 2 Mbps to 300 Mbps. It uses guided (twisted cable, coaxial cable, optical fibre cable) or unguided (microwave, radiowave, infrared, laser) media for transmission. It is more expensive as compared to LAN. It is not secure.
Advantages of Metropolitan Area Network:
- It provides a good backbone for a large network and provides greater access to WANs.
- A MAN usually covers several blocks of a city or an entire city.
Disadvantages of Metropolitan Area Network:
- It can be costly as compared to LAN.
- More cable required for a MAN connection from one place to another.
- The larger network becomes difficult to manage.
- It is difficult to make the system secure from hackers.
WAN-WAN stands for Wide Area Network. WAN covers a large geographical area as compared to LAN and MAN. WAN can contain smaller networks, such as LANs or MANs. Speed of WAN can be 150 Mbps. It uses unguided or unbounded media such a satellite, radiowave, microwave etc. It is not secure and it is expensive. The world’s most popular WAN is the Internet.
- WAN covers a larger geographical area. Hence business offices situated at longer distances can easily communicate.
- It allows sharing of resources and application software among distributed workstations or users.
- The software files are shared among all the users. Hence all will have access to the latest files.
- Organizations can form their global integrated network through WAN.
Disadvantages of Wide Area Network:
- Initial investment costs are higher.
- It is difficult to maintain the network. It requires skilled technicians and network administrators.
- There are more errors and issues due to wide coverage and use of different technologies.
- It has lower security compare to LAN and MAN.
- Security is big concern and requires use of firewall and security softwares/protocols at multiple points across the entire system
PAN- PAN stands for Personal Area Network. It is a network for interconnecting electronic devices. That uses Bluetooth technology. A PAN provides data transmission among devices such as computers, smartphones, tablets and personal digital assistants etc. Its communication range is 10 meters.
LAN | MAN | WAN |
---|---|---|
LAN stands for Local Area Network. | MAN stands for Metropolitan Area Network. | WAN stands for Wide Area Network. |
LAN is often owned by private organizations. | MAN ownership can be private or public. | WAN ownership can be private or public. |
LAN speed is quiet high. | MAN speed is average. | WAN speed is lower than that of LAN. |
Network Propagation (time for a signal to reach its destination) Delay is short in LAN. | Network Propagation (time for a signal to reach its destination) Delay is moderate in MAN. | Network Propagation (time for a signal to reach its destination) Delay is longer in WAN. |
LAN has low congestion as compared to WAN. | MAN has higher congestion than LAN. | WAN has higher congestion than both MAN and LAN. |
Fault Tolerance of LAN is higher than WAN. | Fault Tolerance of MAN is lower than LAN. | Fault Tolerance of WAN is lower than both LAN and MAN. |
Designing and maintaining LAN is easy and less costly than MAN. | Designing and maintaining MAN is complex and more costly than LAN. | Designing and maintaining WAN is complex and more costly than both LAN and MAN. |
Used for College, School, Hospital. | Used for Small towns, City. | Used for Country/Continent. |
UNIT-202
Digital Network Essentials
Digital Network Essentials
- Internet Fundamentals
- Web Browsing
- Web Search Engines
- Need of Computer Network
- Data Communication Fundamentals-Analog and Digital Signal transmission
- Transmission Media-Guided Media: Twisted pairs, Coaxial Cable, Optical Fibers
- Transmission Media-Unguided Media: Radio-wave, Microwave, Satellite, Wi-Fi
- Network Classification-LAN, MAN, WAN, PAN
- Internet Security