Network Types

Network Types:

• Networking is required to make accessible communication between computers possible by a network connection. Networking allows for many possibilities, such as accessing the internet, file sharing, file transferring, networks attacks and system communication. Let’s look at the different types of networking ways in detail.

• Different types of (private) networks are distinguished based on their size (in terms of the number of machines) their data transfer speed and their reach. Private networks are networks that belong to a single organization.

There are usually said to be Five categories of networks:

1.      Personal area network - PAN
2.      Local area network – LAN
3.      Wireless Local Area Networks – WLAN
4.      Metropolitan area network - MAN
5.      Wide area network - WAN

Bluetooth (Personal Area Network)

• Bluetooth is a wireless networking technology designed for very short-range connections (typically just a few metres).
• The idea of Bluetooth is to get rid of the need for all of those cables (e.g. USB cables) that connect our computer to peripheral devices such as printers, mice, keyboards, etc.
• Bluetooth devices contain small, low-power radio transmitters and receivers. When devices are in range of other Bluetooth devices, they detect each other and can be 'paired' (connected)

Typical uses of Bluetooth:

•  Connecting a wireless keyboard to a computer
•  Connecting a wireless mouse to a computer
•   Using a wireless headset with a mobile phone
•  Printing wirelessly from a computer or PDA
•  Transferring data / music from a computer to an MP3 player
• Transferring photos from a phone / camera to another device
•  Synchronising calendars on a PDA and a computer

Local Area Network (LAN)

• A local area network (LAN) is a computer network within a small geographical area such as a home, school, computer laboratory, office building or group of buildings.

• A LAN is composed of inter-connected workstations and personal computers which are each capable of accessing and sharing data and devices, such as printers, scanners and data storage devices, anywhere on the LAN. LANs are characterized by higher communication and data transfer rates and the lack of any need for leased communication lines.

Wireless Local Area Networks – WLAN

• A wireless LAN (WLAN) is a LAN that uses radio signals (WiFi) to connect computers instead of cables

• At the centre of the WLAN is a wireless switch or router a small box with one or two antennas sticking out the back used for sending and receiving data to the computers. (Most laptops have a wireless antenna built into the case.)

•  It is much more convenient to use wireless connections instead of running long wires all over a building.

• However, WLANs are more difficult to make secure since other people can also try to connect to the wireless network. So, it is very important to have a good, hard to guess password for the WLAN connections.

• Typically the range of a wireless connection is about 150m, but it depends how many walls, etc. are in the way.

Metropolitan area network - MAN

•  A MAN is ideal for many kinds of network users because it is a medium-size network. MANs are used to build networks with high data connection speeds for cities and towns.

• The working mechanism of a MAN is similar to an Internet Service Provider (ISP), but a MAN is not owned by a single organization. Like a WAN, a MAN provides shared network connections to its users. A MAN mostly works on the data link layer, which is Layer 2 of the Open Systems Interconnection (OSI) model.

• Distributed Queue Dual Bus (DQDB) is the MAN standard specified by the Institute Of Electrical And Electronics Engineers (IEEE) as IEEE 802.6. Using this standard, a MAN extends up to 30-40 km, or 20-25 miles.

Wide area network - WAN

• A Wide Area Network is a network that extends over a large area.

• A WAN is often created by joining several LANs together, such as when a business that has offices in different countries links the office LANs together.

• Because WANs are often geographically spread over large areas and links between computers are over long distances, they often use quite exotic connections technologies: optical fibre (glass) cables, satellite radio links, microwave radio links, etc.

• The Internet is an example of a global WAN. In fact it is the world’s largest WAN. Computers on the International Space Station are linked to the Internet, so the you could say the the Internet is now the first off-planet WAN!

• many networks can be considered general purpose, which means they are used for everything from sending files to a printer to accessing the Internet. Some types of networks, however, serve a very particular purpose. Some of the different networks based on their main purpose are:-

1.      Storage area network - SAN

2.      Enterprise private network - EPN

3.      Virtual private network - VPN

Let's look at each of these in a bit more detail  

Storage area network - SAN

• Storage Area Networks or sometimes referred to as SAN, are a separate computer network typically based on a fabric of fiber channel switches and hubs, connecting storage subsystems to a heterogeneous set of servers on an any-server-to-any-server basis. A SAN enables direct storage-to-storage interconnectivity and lends itself to taking advantage of new types of clustering technology.

Storage Area Network benefits include the following:

•  Promotes high availability
• Improves data storage management and reduces costs
• Enables efficient hardware deployment and utilization
• Improves data backup efficiency and accessibility
• Enables storage virtualizatio

Enterprise private network - EPN

• number of disparate offices connect those offices to each in a secure way over a network. An enterprise private network is mainly set up to share computer resources.

• Nowadays, networks built by companies are still called enterprise private networks when privacy is maintained through security procedures and tunneling protocols like Layer 2 Tunneling Protocol.

Some of the advantages of an enterprise private network are:

•   The messages are secure because they are encrypted.
•   They are cost effective and scalable.
•  They help to centralize IT resources.

They enable business continuity.

Virtual private network – VPN

•  A virtual private network (VPN) is a network that uses a public telecommunication infrastructure, such as the Internet, to provide remote offices or individual users with secure access to their organization's network. A virtual private network can be contrasted with an expensive system of owned or leased lines that can only be used by one organization. The goal of a VPN is to provide the organization with the same capabilities, but at a much lower cost.

•   A VPN works by using the shared public infrastructure while maintaining privacy through security procedures and tunneling protocols such as the Layer Two Tunneling Protocol (L2TP). In effect the protocols by encrypting data at the sending end and decrypting it at the receiving end, send the data through a tunnel that cannot be entered by data that is not properly encrypted. An additional level of security involves encrypting not only the data, but also the originating and receiving network addresses.