<p> Computer Networks</p><p>A computer network is composed of two or more computers that are able to communicate with each other over a wired or wireless medium to share data and other resources. The communicate using Network data protocols which is a formal set of rules and data structure that ensure computers on that network can “talk” to one another.</p><p>The most common networks you will come in contact with are:  LAN – Local area network which is a set of computers that share a common communications line and usually share a single server (processor) within a small geographic area  WAN – Wide area network is a network that spans a relatively large geographic area (Nortel would have had a WAN)  GAN – Global Area Network is a network that spans between geographically distinct cities</p><p>There are many different ways a network can be set up (different Topologies) some of these are shown below:</p><p>The most common topology at your home would likely be a star type of topology. In a WAN like at the school the most common would likely be the Bus. Parts in a home network and terms you should know</p><p>Connection to ISP Mode Router / m Server Or hub hu b Computer</p><p>The ISP (Internet Service Provider) is the networks connection to the internet.</p><p>Modem - the connecting device that allows us to connect to the ISP and in turn the internet as it converts analogue signals to digital signals and visa versa</p><p>Router – considered a residential gateway, the location all connections can be “connected” together, allowing incoming traffic to be split into multiple connections and outbound traffic to be piped out of a single connection</p><p>Server – a computer that is designated as the connection to the internet. It typically has more security protocols and requires server/client network application (e.g. Novell Client) to establish communications within the network. It can also be the main resource for backups and /or the location for large database data to be stored for the network (a situation where common information is required by users)</p><p>Hub – a device transfer data from one signal and make it available to multiple hosts and visa versa</p><p>NIC – (network interface controller) – An expansion card that has an Ethernet port to connect a computer to a network. Modern computers have this embedded in the motherboard.</p><p>Cables - wires bound together for a particular purpose Ethernet – 8 wires bundled to connect network components together </p><p>Node – computers on a network can sometimes be called nodes. Networking applications and Protocols you should be aware of:</p><p>Ethernet – a protocol but you are not responsible to know how it works other than it sends packets and if they collide they need to wait a random amount of time before retrying to send the packet</p><p>VoIP – Voice over Internet Protocol – a way to send analog audio signals into digital signals and send them over the internet (can be done on a phone using an audio telephone adapter, IP phone (has Ethernet connection), or computer to computer.</p><p>Streaming media – refers to transferring data so it can be processed at a steady and continuous stream.</p><p>FTP (File transfer Protocol) – used to transfer files specifically from one host (computer) to another</p><p>Email – a system for sending and receiving electronic mail from one computer to another or one address to another</p><p>Instant messaging – the transmission and reception of an electronic message from computer to another using software that displays immediately on a window of the recipient computer</p><p>TCPIP – (Transmission Control Protocol/Internet Protocol) a protocol standard to transmit data over a network and the internet</p><p>VPN – Virtual private network – a protocol that allows a connection that is secure and private to a particular computer by using a public network.</p><p>Point – to - point (PPP) – refers to the transfer of information from one point to the next in a number of nodes (usually servers or hubs) until it reaches its end point.</p><p>Most Common ways to share information on a network Operating system supported and implemented are:  Shared file access  Shared printer access  Shared internet access</p><p>Note: A computer that is connected to a network is called a workstation, one that is not connected to the network is called a stand alone machine.</p>