Reading notes for October 6 class

Local area network reading
• local area network: computer network that interconnect computers in a limited area.
o usually high data-transfer rates
o Ethernet and Wi-Fi are two most common technologies currently used to build them
• Need for these came from increased use of computers at universities and labs
• NetWare was chief network operating system from 1983 to mid 1990s, when Microsoft grabbed a hold of the market
• Wi-fi is now most common technology used with LANs to accommodate laptops and mobile devices
• LANs can have connections with other LANs via leased lines or services across the internet using virtual private network technologies
Computer network reading
• Computer network: often referred to as a network, is a collection of hardware components and computers interconnected by communications channels that allow sharing of resources and information
o Rules and data formats for exchanging information- defined by communications protocols
 Ex. Ethernet, internet protocol suite
• Computer networks: core of modern communication
• Key characteristics of networks:
o Facilitate communications
o Permit sharing of files, data and other types of information
o Share network and computing resources
o May be insecure
o May interfere with other technologies
o May be difficult to set up
• Communications protocol defines the formats and rules for exchanging information via a network
• Ethernet- family of connectionless protocols used in LAMs with a flat addressing scheme.
• Internet Protocol Suite- foundation of all modern internetworking
• Asynchronous Transfer Mode- switching technique for telecommunication networks
o Uses time-division multiplexing and encodes data into small, fixed-sized cells, which makes it different from IPS or Ethernet- which use variable sized packets or frames
o Good choice for network that needs to handle both high-throughput data and real-time, low-latency content such as voice and audio
• Networks- often classified by physical or organizational extent or purpose
o Personal area network: ex. Pcs, printers, fax machines, telephones
o LAN- each computer or device is a node
 All of these connected devices must know the network layer (layer 3)
 Home network- residential LAN
• Backbone Network- part of computer network infrastructure that interconnects various pieces of network and provides a path for exchange of information between different LANs, or subnetworks
• Wide Area Network- large computer network that covers a large geographic area such as a city; uses a communication channel that combines many types of media
o Often uses transmission facilities provided by common carriers- like telephone companies
• Overlay network- virtual computer network that is built on top of another network
o Ex. internet