Chapter 5 - CS3 - Networks Flashcards
TCP/IP
Transmission control protocol/ Internet protocol
INTERMEDIARY protocol that allows networks with different protocols to communicate with each other
What were the first four locations hooked up to the Internet (ARPANET)?
UCLA, Stanford, MIT, & University of Utah
Packet
The fundamental unit of data transmitted over the Internet. When a device intends to send a message to another device (for example, your PC sends a request to YouTube to open a video), it breaks the message down into smaller pieces, called packets.
What does each packet have?
The sender’s address, the destination address, a sequence number, and a piece of the overall message to be sent
Hub
A simple network device that connects other devices to the network and sends packets to all the devices connected to it
Bridge
A network device that connects two networks together and only allows packets through that are needed
Switch
A network device that connects multiple devices together and filters packets based on their destination within the connected devices
Router
A device that receives and analyzes packets and then routes them towards their destination. In some cases, a router will send a packet to another router; in other cases, it will send it directly to its destination
IP Address
Every device that communicates on the Internet, whether it be a personal computer, a tablet, a smartphone, or anything else, is assigned a unique identifying number called an IP (Internet Protocol) address.
IPv4 vs. IPv6
Historically, the IP-address standard used has been IPv4 (version 4), which has the format of four numbers between 0 and 255 separated by a period (e.g., 107.23.196.166). As the use of the Internet has proliferated, the number of IP addresses needed has grown to the point where the use of IPv4 addresses will be exhausted. This has led to the new IPv6 standard, which is formatted as eight groups of four hexadecimal digits, such as 2001:0db8:85a3:0042:1000:8a2e:0370:7334.
Domain name
A domain name is a human-friendly name for a device on the Internet
Top-level domain (TLD)
.com, .net, .gov, .org
Domain name system (DNS)
Directory on the Internet
When a request to access a device with a domain name is given, a DNS server is queried. It returns the IP address of the device requested, allowing for proper routing
Packet-switching
When a packet is sent from one device out over the Internet, it does not follow a straight path to its destination. Instead, it is passed from one router to another across the Internet until it is reaches its destination. In fact, sometimes two packets from the same message will take different routes! Sometimes, packets will arrive at their destination out of order. When this happens, the receiving device restores them to their proper order.
Protocol
In computer networking, a protocol is the set of rules that allow two (or more) devices to exchange information back and forth across the network.
What was revolutionary about Web 2.0?
Anyone could post content to the web, without the need for understanding HTML or web server technology.
What drove growth for PCs? What drove growth for the internet? (i.e., what was the “killer” app for these?)
Spreadsheets was “killer” app for PC - people bought PCs just so they could use spreadsheets
E-mail is “killer” app for the internet - it drove demand for the internet
What is dial-up internet access?
A modem connected the computer to a telephone line
What is a broadband connection?
Internet connection w/ speeds of at least 256,000 bps (bits-per-second)
What is wi-fi?
A technology that converts internet signal into radio waves
Devices w/ a wireless adapter can pick up the radio waves
What does the term VoIP mean?
Voice over Internet Protocol - a way to transfer sound (have voice conversations) over the Internet
(converts sounds to digital format for transmission over the Internet then reassembles at the other end)
LAN
Local area network - allows computers within same vicinity to connect to each other & other devices; usually in the same building or on the same campus
WAN
Wide area network - network over a wider area, such as locations across different cities or states
Intranet
Organization’s internal web pages - can only be accessed in company’s network
Extranet
Part of the org’s web pages that can be accessed by external parties (e.g., customer checking their order, suppliers checking inventory)
Internet
Interconnected network of networks
Metcalfe’s Law
Value of communications network equal to the square of the number of users
PAN
Personal Area Network
Connects devices & computers in an individual’s workspace
WLAN
Wireless LAN
Network architecture
Configuration of computers, devices, and media on a network
Client-server, peer-to-peer
Node
A device or data point in the network - PC, phone, printer
Connection point, redistribution point, or communication endpoint
Ethernet
Traditional technology for connecting to the Local Area Network; enables devices to communicate via a protocol
