Computer Network Types

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Defining the types of computer networks is not an easy task. Networks can range from two computers connected together sharing a few resources (files or printers for example) up to millions of computers spanning the globe. The purpose of this post is to introduce the reader to a high-level overview of computer networks. Perhaps a place to start is simply listing the types of networks. Belden, the company that makes cables among other things has at their website an article called 11 Types of Networks Explained: VPN, LAN & More that lists defines 11 types of networks. It was written by Stéphane Bourgeois. For each of these types, several books have been written on each type.

  • Personal Area Network (PAN)
  • Local Area Network (LAN)
  • Wireless Local Area Network (WLAN)
  • Campus Area Network (CAN)
  • Metropolitan Area Network (MAN)
  • Wide Area Network (WAN)
  • Storage-Area Network (SAN)
  • System-Area Network (also known as SAN)
  • Passive Optical Local Area Network (POLAN)
  • Enterprise Private Network (EPN)
  • Virtual Private Network (VPN)

Internetwork

An internetwork is a network of networks. The Internet is the largest network in existence on this planet an is an internetwork. The Internet connects WANs, LANs and Home networks. From a high-level perspective the Internet works on Client-Server model.

Classification of Computer Networks

Now that have a list of types of networks we will back up and look at how we might classify networks. There is an article at TutorialsPoint.com called Data Communication & Computer Network that describes this well. Computers that share digital data can be connected to each other by either wired or wireless media, which gives us one way to classify networks.

This article classifies computer networks four ways as follows:

  • Geographical span
  • Inter-connectivity
  • Administration
  • Architecture
Geographical Span
  • It may be spanned across your table, among Bluetooth enabled devices,. Ranging not more than few meters.(PAN)
  • It may be spanned across a whole building, including intermediate devices to connect all floors. (LAN)
  • It may be spanned across a whole city.(MAN)
  • It may be spanned across multiple cities, states or provinces.(WAN)
  • It may be one network covering whole world.
Inter-connectivity

There are different ways and combination of ways to connect different parts of a computer network together. These individual parts are often called nodes. Connectedness can be described either logically , physically , or both ways.

  • Every single device can be connected to every other device on network, making the network mesh.
  • All devices can be connected to a single medium but geographically disconnected, created bus like structure.
  • Each device is connected to its left and right peers only, creating linear structure.
  • All devices connected together with a single device, creating star like structure.
  • All devices connected arbitrarily using all previous ways to connect each other, resulting in a hybrid structure.
Administration

From an administrator’s point of view, a network can be private network which belongs a single autonomous system and cannot be accessed outside its physical or logical domain. A network can be public which is accessed by all. This is all about who.

Network Architecture

Client-Server,peer-to-peer or hybrid.

  • One or more computer systems can be acting as a Server, whereby they fullfill requests of clients. The Server takes and processes requests on behalf of Clients. The Windows domain model is a form of this type of network.
  • Two systems can be connected Point-to-Point, or in back-to-back fashion. They both reside at the same level and called peers.
  • There can be hybrid network which involves network architecture of both the above types.
Network Applications

Networking is about sharing resources, but what do we mean when we talk about resources? Why use networks in the first place?

  • Resource sharing such as printers and storage devices
  • Exchange of information by means of e-Mails and FTP
  • Information sharing by using Web or Internet
  • Interaction with other users using dynamic web pages
  • IP phones
  • Video conferences
  • Parallel computing
  • Instant messaging

Local Area Networks (LANs)

LANs fall under three categories: peer-to-peer, client/server and domain-based. LANs are probably the most discussed type of network and it is a good place to start if you are new to networking. The Windows Server is also a good place to start your studies, along with the lower-level hardware-based topics that you will find in the Network+ certification curriculum. Windows server is a domain-based model.

LANs fall under three types: peer-to-peer, client/server and domain-based. Their main purpose is to share resources. What resources, what will the resources be names, who will be sharing the resources, who will be accessing the resources, when will the resources be accessed, where will the resources physically reside on the network and other questions make networking a challenging endeavor.

Peer-toPeer (P2P)

Peer-to-peer (P2P) is a decentralized communications model in which each party has the same capabilities and either party can initiate a communication session. Unlike the client/server model, in which the client makes a service request and the server fulfills the request, the P2P network model allows each node to function as both a client and server.