Types of Networks

COMP1260 > Computers and Networks

Introduction Nowadays we see networking devices all around. A large population checks emails, chats with friends via instant messaging services or checks a store’s website for products, and all this on a daily basis. To that people use many different devices to connect to networks all around us to communicate. Networks we use are for example the internet, that we reach through telephone lines or wireless devices such as smartphones, computers and other devices, the company network we use to communicate at work and do various task like sending files to coworkers and storing data on storage servers or maybe even use Voice over IP technologies to call different departments. You would surprised by how often we use computer networks everyday, when you think about it. Maybe you even wondered what a network is and in what ways networks differ. This article will discuss some common network types we deal with throughout our lives. Networks connect 2 or more computers, including peripheral devices, via special cables and devices like routers, switches and Ethernet Cables. An example for a big network would be the internet, being a network of networks that you can connect to through your internet service provider (e.g. Shaw or MTS). Companies have smaller scaled networks consisting of ~10-100 computers. If there are enough machines, you often see sub networks interconnected to form a bigger network. A good example for that would be a university’s network system. Networks are also very diverse and use different kind of technologies that you may read about in the following sections. bla

...by students sdfljasdlkfjasdl </td> </tr> </table> Network Types LAN – Local Area Network Figure 1: U of M network diagram A Local Area Network (LAN) is the most common type of networks you will find. This type of network usually covers a relatively small physical area like an office or even an entire building. A LAN could be either a peer-to-peer network where only two computers are directly connected to each other via a Crossover Ethernet Cable and each having a network card, or using one or several routers or switches to connect more than 2 computers. Routers assign IP-addresses to computers themselves and use either Crossover Cables or Straight-Through Cables, whereas switches use Straight-Through Cables and do not assign IP-addresses; each computer network adapter (network card) needs to be (manually) configured to have a unique IP-address within the network. Nowadays, wireless routers are becoming very popular. As the name suggests, those routers are able to connect computers in a wireless fashion using wireless technology and are used to build a Wireless Local Area Network (WLAN). Computers connecting to WLAN need a special network adapter (wireless network adapters) to communicate wirelessly with the network. PAN – Personal Area Network A Personal Area Network (PAN) is a small scaled LAN with only a few computers. They are usually for used for home networks where people connect there personal computers to share files, modems and/or printers. MAN – Metropolitan Area Network A Metropolitan Area Network (MAN) is a big scaled LAN or several LANs connected to build a metropolitan wide network and do not extend a towns or cities boundaries. CAN – Campus Area Networks A Campus Area Network (CAN) is essentially a MAN but with smaller boundaries covering only an entire academic campus. WAN – Wide Area Network A Wide Area Network (WAN) differs from all other networks by its geographically and spatially unlimited size. Usually it consists of many networks of any types, all connected across long distances via telephone lines. The best example is the biggest WAN in the world, the internet. Another example would be Canada’s computer networks used by the government that stretches out national wide. Protocols Networks communicate via the use of protocols. Protocols enable computers in a network to translate, send and receive information to and from other computers and devices. The ongoing communication between devices in a network is also know as network traffic. There are many different types of protocols like LAN protocols, WAN protocols and routing protocols. Most operating systems in connection with a network adapter use a very commonly used and general protocol suite called TCP/IP whose original name is Internet Protocol Suite. TCP stands for Transmission Control Protocol and IP means Internet Protocol. Together, they build a suite that can be used in a wide range of network types, from LAN to WAN, and is used by the majority of network-capable devices we handle on a daily basis. Hardware components Network Adapter A network adapter/card, or network interface card (NIC) is a device or module in computers that are used as an interface to physically connect a computer (of any form) to a network, may it by using cables or wireless network cards. Switch A switch serves as a central unit in a network to which several computers connect to. The device then coordinates network traffic only between those computers connected to it. This means that it is not capable of connecting other networks to do routing work between them. To obtain an internet gateway on the switched network it is necessary to have one of the computers with an internet connection that is connected to the network to be designated as the internet gateway. Of course this computer will need two network adapters to over the service, one card to connect to the network and the other to a modem. Router Routers are essentially switches with additional function. They are usually used to connect multiple networks, which can be of different types, which differentiates them from switches. The most common connection you will find is between LAN and WAN/Internet. Routers for home networking are used to offer a shared internet connection to all connected devices and also enable file-sharing. You can find routers with cable ports only to build a wired network, or routers with wireless technology only to build wireless networks, or you can have router that combines both technologies to build a mixed network, LAN plus WLAN. References Previous Page: Hardware Next Page: Understanding the Internet