ITGS Types of network

ITGS Local Area Networks (LAN) A network confined to one geographical area, such as a home, an office building, or a school campus. All computers belong to one organization LANS provide many advantages: Users can log in from anywhere in the organization Easy sharing of peripherals, files, appications

ITGS Wireless LAN’s (WLAN) Personal Area Networks (PAN) A local network in which some or all devices connect wirelessly Common in businesses and schools for desktops to have wired Ethernet access, while laptops and PDA’s connect using Wi-Fi Personal Area Networks (PAN) Created when devices such as mobile phones or PDAs are connected to a computer PANS cover a small area Normally used to transfer data or synchronize devices PANs are created using bluetooth, USB cables and Infrared

ITGS MANs and WANs (Metropolitan Area Networks/ Wide Area Networks) MANs cover relatively large areas like very large university campuses or cities Series of LANs connected together WANs - even larger networks covering multiple cities or countries The internet is a WAN, formed by connecting many computers and LANs together to form a nework of networks Storage Area Networks (SAN) A specialized network dedicated to storing data Contain multiple hard disks which are attached to a LAN using high speed optical fiber connections

ITGS Virtual Private Networks (VPN) SAN storage appears to client computers as local storage (like a hard disk inside the client computer) Advantage: all storage is maintained in a single location Backup tasks are much easier Easier to add storage and distribute it across network clients Virtual Private Networks (VPN) Wide area networks like the Internet are insecure because of how data travels across them VPN - uses encryption to create an encrypted tunnel from one computer to a local network in another location For example: a businessman traveling in a London hotel can use a VPN to connect to his company’s LAN in the main New York office, allowing him to access the LAN’s files and printers

ITGS the VPN software automatically encrypts all data sent backwards and forwards through the tunnel, meaning transactions are secure from eavesdroppers Virtual LAN (VLAN) Connects geographically separated computers or LANs into one virtual network Similar to a VPN, except entire networks connect with eachother, rather than just individual computers

ITGS Network connections Wired connections Fiber optic cables Transfer data by sending light down an extremely thin glass tube Connections are extremely fast, able to transfer data at well over 40 gbps (gigabits per second) Each cable is able to contain multiple indpendent optical fibers Extremely expensive Slow to catch on with home and small business users Mostly used for high speed backbone connections which deal with huge volumes of traffic

ITGS Cable internet access DSL (digital subscriber line) One of the most common forms of broadband internet access in homes Cable uses existing cable TV network to transfer data, removing the need to have additional cable installed DSL (digital subscriber line) Connections use existing telephone network Cable modem is used to convert data for use over the network Unlike fiber optics, the main advantage of cable and DSL connections is that high speed connections can be achieved without having to lay additional networks. Disadvantage of cable networks: users in the same area share the network, reducing bandwidth

ITGS Dialup Relatively old technology that connects using a standard telephone line Because computers are digital and phone lines are analog, the computer must be connected to a Modem to use the phone network Common before broadband became popular Slow speed: up to 56 Kbps Phone line can’t be used for anything else while connected Dialup connections must be paid for by the minute Ethernet LAN cables that can transfer data at high speeds over short distances