Transcript ITGS
ITGS Networks ITGS • Networks and components – Server computers normally have a higher specification than regular desktop computers because they must deal with many client requests at once • Feature multiple processors and extra RAM • Multiple hard disks offering several terabytes of storage – Arranged as a RAID array » Redundant Array of Independent Disks - failover system for hard disks in which multiple hard disks are connected together » the info from one hard disk is mirrored onto another one every time something is saved, so that if a hard disk fails, the computer switches to its mirror ITGS • Client computers – Regular desktops, laptops or mobile computers that connect to a network to use its services • When connecting to a network, clients have to authenticate themselves ITGS • Network components – Clients and servers • Client-server networks File servers - store users files and data and controls access to them Application servers - store software programs which can be delivered to client computers Print servers - manage printers attached to the network, controllng access to them and maintaining a queue of documents waiting to be printed. ITGS Database servers - hosts large databases of information and manages access to it Authentication servers, or domain controllers .responsible for processing login requests and determining whether a user should be allowed access to the network ITGS – Firewall • If a network is connected to the internet, a server will be dedicated to managing the security of info coming in and out of the network ITGS • Sharing devices – Saves money (as in printer sharing), because only one printer must be purchased for the network • How shared devices connect – Shared devices may connect directly to a network hub or switch using an ethernet or USB connection – Or they can be directly connected to a computer, either client or server ITGS • Hubs, routers and switches – Hubs, routers and switches all perform a similar basic task, but the way in which they operate is different • Include a number of Ethernet ports, allowing multiple computers to connect to them on a LAN, or Local Area Network Hubs When a hub receives data, it simply rebroadcasts it to every connected device, including the one that sent it in the first place ITGS •When hubs send data to every computer connected to them, a lot of bandwidth is wasted •Switches save bandwidth by routing data only to the intended computer, not all of them. •Switches •Inspect the data they receive to determine the destination, then forwarded only to the intended recipient ITGS • Routers connect two or more separate networks, acting as a gateway through which all data entering and leaving the network passes. – A router can also filter the info that passes through it, only allowing access to certain computers. • Example: – A switch connects all of the computers in the Journalism Rooms (LAN) – A router connects the school network with another network, such as the district ITGS • Broadband routers – Often supplied by Internet Service Providers (ISPs)when installing Internet access in a business or home » Allows you to connect your home computer to the Internet and connect multiple computers to form a home network