SLR21 Networking and the internet Flashcards
Physical star topology
“A topology for a Local Area Network (LAN) in which all nodes are individually connected to a central connection point, like a hub or a switch.”
Logical bus network topology
“A network physically wired in star topology can behave logically as a bus network by using a bus protocol and appropriate physical switching.”
Peer-to-peer
“A method of network organisation in which network stations can share resources on other network stations, so one station can use a printer on another station or save data on another station’s local storage.”
Client-server
“A method of network organisation in which network stations make use of resources available at one or more servers.”
Wi-Fi
“A facility that allows computers, smartphones or other devices to connect to the internet or communicate with one another wirelessly within a particular area.”
Carrier Sense Multiple Access with Collision Avoidance
“A network multiple access method in which carrier sensing is used, but nodes attempt to avoid collisions by transmitting only when the channel is sensed to be ‘idle’.”
Request to Send/Clear to Send
“An optional mechanism used by many wireless networking protocols to reduce frame collisions introduced by the hidden node problem.”
Service Set Identifier
“The name assigned to a Wi-Fi (wireless) network. All devices in the network must use this case-sensitive name to communicate over Wi-Fi, which is a text string up to 32 bytes long.”
Packet switching
“A method of sending data over a wide area network in which the message is broken into several parts. These parts are sent independently via the optimal route for each packet and reassembled at the destination.”
Router
“In packet-switched networks like the internet, a router is a device (or in some cases, software) that determines the best way for a packet to be forwarded to its destination.”
Gateway
“A network node that connects two networks using different protocols together. While a bridge is used to join two similar types of networks, a gateway is used to join two dissimilar networks.”
Routing
“The process of moving packets across a network from one host to another. It is usually performed by dedicated devices called routers.”
Uniform Resource Locator
“The address of a page on the World Wide Web.”
Fully Qualified Domain Name
“Sometimes also referred to as an absolute domain name, it specifies its exact location in the tree hierarchy of the Domain Name System (DNS). It specifies all domain levels, including the top-level domain and the root zone. A fully qualified domain name is distinguished by its lack of ambiguity; it can be interpreted only in one way.”
Domain name
“The part of a network address which identifies it as belonging to a particular domain.”
IP address
“A unique string of numbers separated by full stops that identifies each computer using the Internet Protocol to communicate over a network.”
Domain Name System
“The internet’s equivalent of a phone book. They maintain a directory of domain names and translate them to Internet Protocol (IP) addresses; this is necessary because, although domain names are easy for people to remember, computers or machines access websites based on IP addresses.”
Firewall
“A computer application used in a network to prevent external users from gaining unauthorised access to a computer system.”
Packet filtering
“A firewall technique used to control network access by monitoring outgoing and incoming packets and allowing them to pass or halt based on the source and destination Internet Protocol (IP) addresses, protocols and ports.”
Proxy server
“A dedicated computer or software system running on a computer that acts as an intermediary between an end-point device like a computer and another server from which a user or client is requesting a service.”
Stateful packet inspection
“A firewall technology that monitors the state of active connections and uses this information to determine which network packets to allow through the firewall.”
Symmetric encryption
“The oldest and best-known encryption technique. A secret key, which can be a number, a word, or just a string of random letters, is applied to the text of a message to change the content in a particular way; this might be as simple as shifting each letter by several places in the alphabet.”
