Chapter 13 Flashcards
Internet backbone
a collection of large national and international networks (most of which are owned by commercial, educational, or govn’t organizations)
IXP
made up of one or more internet switches to which internet service providers connect to
T line
carried digital data over twisted pair lines.
backbone ISP initially connect with T lines.
Point of presence (POP)
individual users enter a ISP through a POP.
- usually a modem, switch, routers, etc.
client/server model
clients: devices such as computers, tablets, and smartphones that use browsers to request services such as web pages
servers: web servers, commerce servers, file servers
web server
computers that run specialized OS enabling them to host web pages and to provide requested info to clients
commerce servers
computers that host software that enables buyers to buy goods and services over the web
file servers
computers that are deployed to provide remote storage space or to act as storehouses for files that users can download
computer protocol
the set of rules for exchanging electronic info
why was protocols invented?
anyone can use their computer system and be able to communicate with any other computer using the same protocol
open system
it’s design would be made public for access by any interested party
- each protocol has to be open system
opposite of open system?
poprietory system
proprietary system
private system
circuit switching
a dedicated connection is formed between two points and the connection remains active for the duration of the transmission
why is circuit switching important?
when communications must be received in order they were sent (phone conversation)
what device is circuit switching usually used for?
a phone, never computers
if computers don’t use circuit switching then what do they use?
packet switching
packet switching
data is broken into smaller chunks (data packets) and are sent over various routes at the same time. when the packets reach their destination they’re reassembled by the receiving computer.
what info does a packet contain?
- an address the packet is being sent to
- the address the packet comes from
- reassembly instructions if the data is split up
- the data that is being transmitted
internet protocol (IP)
sends data between computers on the internet
transmission control protocol (TCP)
prepares data from transmission and provides for error checking and resending lost info
user datagram protocol (UDP)
prepares data for transmission: lacks resending ability
file transfer protocol(FTP)
enables fies to be downloaded to a computer or uploaded to other computers
telnet
enables user to log in to a remote computer and work on it as if sitting in front of it
simple mail transfer protocol(SMTP)
used for transmission of email messages across the internet
DHCP
takes a pool of IP addresses and shares them with host on a network on as needed basis
dynamic host configuration protocol(DHCP)
takes a pool of IP addresses and shares them with host on a network on as needed basis
Real-time transport protocol (RTP)
network protocol for delivering audio and video over IP
TCP/ IP
main suite of protocols
internet corporation for assigned name and numbers (ICANN)
IP addresses must be registered with ICANN to ensure they’re unique and haven’t been assigned to other users
dotted decimal number/ dotted quad
another name for an IP address
Octet
each of the 4 numbers in a dotted decimal
ex) 119.63.62.1939
internet protocol version 4 (ipv4)
the original ip addressing scheme. it was apparent they were gone run out of IP addresses
internet of things (IOT)
term for explosive growth of internet enabled devices
internet protocol version 6 (ipv6)
IP addressing scheme created by the IETF to make IP addresses longer
connection oriented protocol
requires two computers to exchange control packets, thereby setting up the parameters of the data exchange session, before sending packets that contain data
three way handshake
- TCP uses to establish a connection
- your computer establishes a connection to the ISP and announces it has a email to send
- the ISP server responds that it’s ready to receive the email
- your computer acknowledges the ready state of the server and begins to transmit the server
connectionless protocol
doesn’t require any type of connection to be established between two computers exchanging info
positive acknowledge (ACK)
confirmation that the email was received
negative acknowledge (NAK)
the packet wasn’t received in understandable form
how are IP addresses assigned?
statically or dynamically
static addressing
the IP address for a computer never changes and is most likely assigned manually by a network administrator or ISP
dynamic addressing
your computer is assigned a temporary address from an available pool of IP addresses
second level domain
whatever is before the .com or .net or whatever
how does your computer know the IP address of other computers?
when you enter a URl, the computer converts it to a IP address
domain name system (DNS) server
a database that functions like a phonebook
root DNS server
knows the location of all the DNS servers that contain the master listings for an entire top level domain
internet cache
a section of your hard drive that stores info you may need later ( IP addresses, etc.)
hypertext markup language (HTML)
a set of rules for marking up blocks of text so that the browser knows how to display them
HTML5
- reduce the need for plug ins
- support better error handling
- support advanced audio and animation effects
- make it easier to draw graphics
cascading style sheet (CSS)
a list of rules that defines in one single location how to display HTML elements
extensible markup language (XML)
describes the content in terms of what is being described rather than how it’s to be displayed
JavaScript object notation (JSON)
a data interchange standard that is easy for humans to read and write
hypertext transfer protocol (HTTP)
was created especially for the transfer of hypertext documents across the internet
transport layer security (TLS)
updated extension of the secure sockets layer
web application software consist of two parts
- client side
* server side
clients side
lives on the users computer
server side
lives on the servers computer
server side program
program that runs on a web server rather than on your computer
common gateway interface (CGI)
enables functionality beyond the simple display of infk
what are the two main approaches to client side program?
- HTML embedded scripting language
* applet
HTML embedded scripting language
tucks programming code directly within the HTML of a web page ( most popular is JavaScript)
applet
a small app actually located on the server
dynamic HTML (DHTML)
HTML and Java script. used to create lively and interactive websites
JavaScript
commonly used scripting language for creating DHTML effects
Document Object Model (DOM)
JavaScript use to orgainze the objects and page elements
who created the internet
Ray Tomlinson
simple mail transfer protocol (SMTP)
responsible for sending email along the internet to it’s destination
simple mail transfer protocol (SMTP)
responsible for sending email along the internet to it’s destination
multipurpose internet mail extension (MIME)
used to attach files to email