cs160 chapter 4
DESCRIPTION
TRANSCRIPT
NETWORKING AND THE INTERNET
CS160
NETWORK CLASSIFICATIONS
Networking and the Internet
NETWORK CLASSIFICATIONS
Size
Local Area Network (LAN)
Metropolitan Area Network (MAN)
Wide Area Network (WAN)
Intellectual Property
Open
Closed
TOPOLOGIES
PROTOCOLS
Token Ring
Messages passed in one direction
Each message ends back at original sender
PROTOCOLS (CONTINUED)
Carrier Sense, Multiple Access with Collision Detection (CSMA/CD)
Message sent across common bus
Only intended recipient reads
On collision, each sender waits before re-sending
COMBINING NETWORKS
Repeater
Physically connects two networks
Passes all traffic
May amplify signals to compensate for increased length
Bridge
Passes only messages for machines on a given segment
COMBINING NETWORKS (CONTINUED)
Switch
Connects two or more segments
Routes messages only to segment where recipient is found
When using repeaters, bridges, or switches the result is one large, homo-geneous network
COMBINING NETWORKS (CONTINUED)
Router
Connects two or more networks with dissimilar topologies
Builds networks of networks called internets
INTERPROCESS COMMUNICATION
Client-server
One server, many clients
Server must execute continuously
Client initiates communication
INTERPROCESS COMMUNICATION (CONTINUED)
Peer-to-peer (P2P)
Two processes communicating as equals
Peer processes can be short-lived
THE INTERNET
Networking and the Internet
THE INTERNET
Proper noun
Originated in Defense Advanced Research Projects Agency (DARPA) in 1960’s
Shifted from government to academia to commercial
INTERNET ARCHITECTURE
Domain: portion of the Internet that network or internet controlled by a single authority
Connected to the rest of the Internet by a router called a gateway
Internet Corporation for Assigned Names & Numbers (ICANN): Oversees the registration of domains
STRATEGIES FOR CONNECTING TO THE
INTERNET
Internet Service Provider (ISP): Provides connectivity to the Internet
Popular means of connecting:
Traditional telephone (dial up connection)
Cable connections
DSL
Wireless
Satelite
INTERNET ADDRESSING: IP ADDRESSES
Every computer on the Internet is assigned an Internet Protocol (IP) Address
IPv4
32-bits (4 bytes)
232 = 4,294,967,296 unique addresses
“Dotted quads” xxx.xxx.xxx.xxx
INTERNET ADDRESSING : IP ADDRESSES
(CONTINUED)
IPv6
128-bits (7 bytes)
2128 = 3.4 × 1038
5 × 1028 addresses for each of the 6.5 billion people alive today
252 addresses for each star in the known universe
10 billion billion billion times as many addresses as IPv4
INTERNET ADDRESSING: HOST NAMES
Mnemonic address made up of two parts: Domain name
Assigned by a registrar Example: linnbenton.edu Top level domain: Classification of domain owner
By usage – Example: .edu= education By country – Example: .co.uk = England
Subdomains and individual host names Assigned by domain owner Example: ml.linnbenton.edu
Translation between mnemonic addresses and IP addresses handled by name servers
TRADITIONAL INTERNET APPLICATIONS
World Wide Web (WWW) Electronic mail
(E-mail) File transfer protocol
(FTP)
Instant messaging (IM) VOIP Internet relay chat (IRC) Telnet
Secure Shell (SSH) Newsgroups
Archie Early index of files
available on FTP sites
Gopher Hierarchical menu-
based system for document retrieval (WWW-like)
Jughead Search engine for
Gopher
Veronica Another search engine
for gopher
THE WORLD WIDE WEB
Networking and the Internet
THE WORLD WIDE WEB
Hypertext and HTTP
Hypertext markup language (HTML)
Hypertext transfer protocol (HTTP)
Browser gets documents from Web server
Web page
Documents identified by URLs
Uniform resource locator
World Wide Web Consortium (W3C)
Standards body
A TYPICAL URL
HTML
Set of tags used to identify elements of a web page
Designed to be very simple to learn and use
<p>…</p>
<h1>…</h1>
<img src=“foo.jpg />
<a href=“http://www.linnbenton.edu” />
SAMPLE WEB PAGE