Transcript Internet I - Loyola Law School

Comparative Telecommunications Law
Spring, 2007
Prof. Karl Manheim
14: Internet I (Tech Basics)
Copyright © 2007
What is the Internet
An InterNetwork
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A global connection of public networks
 Consisting of hardware, transmission, other layers
 predominant vehicle for telecommunication
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carrying ~ 10 exabytes of information annually <link>
 Exa = 1 quintillion (10^18 or 2^60)
 1,000,000,000,000,000,000 bytes (~ words)
Compare all human communication (1999) ~ 12 exabytes
How the Internet works <article>
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What is the Internet
Interconnection requires standards

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Who should set them?
If not by gov’t, how is interoperability assured?
 Voluntary adoption by networks (“buy-in”)
 New standards by IETF (private org)
Internet protocols (standards)
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IP : datagrams/packets (info blocks)
TCP : transmission/routing protocols
 End-to-end principle
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The Internet runs on TCP/IP
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U.S. Backbone Connectivity
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The Layers of the Internet
Hardware: Physical Devices & Connections
Transmission modality: Method
Transmission protocols: Language
Addressing: Delivery Instructions
Applications: Particular Services (& their code)
Data: Usable Information
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The Layers of the Internet
Data: Usable Information
Applications: Particular Services
Addressing: Delivery Instructions
Transmission protocols: Language
Transmission modality: Method
Hardware: Physical Devices
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Internet Hardware
Computers & other processing devices
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Including storage devices (e.g., raid arrays)
Wire “Backbone” (mostly fiber & radio)
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Increasingly wireless
The “Inter-network”
Currently, mostly owned by major telcos
Switches (routing devices)
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Compare automobile traffic
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Transmission Modality
Digital transmission
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Binary digits, 0 and 1
 That’s what modern computers use
 To put data on an analog tel network, you need a
ModulatorDemodulator
Packet Switching
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Discrete length Packets of binary information
Routing
 Each packet sent/routed/received independently
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Redundancy, robustness
 Compare “circuit switching” for telephony
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Transmission Protocol
Language of the Internet
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Sender and receiver both know binary digits
and packets, but must code/decode the same
 Must be device independent (cross-platform)
 Must be human language independent
 Must be application independent
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TCP/IP
Everything that goes over the Internet uses TCP/IP
 IP (Internet Protocol)
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communicable rules for packets
 TCP (Transmission Control Protocol)
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sequencing & error checking (assure packets are readable)
assuring “end-to-end” connections and reliability
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TCP/IP Packets
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source
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Addressing
IP Addresses
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<tutorial>
137.204.190.254
 4 numbers (quartet), 2 base 8 (0-255)
 Network address
 Specific computer address
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www.lls.edu
Domain Name
Servers translate
IP numbers into
URLs
 Universal Resource Locator (URL) [web address]
 Top Level Domain (ccTLD)
 Second Level Domain (SLD) [network address]
 Computer address
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Comparing IP Numbers with PSTN
157.242.136.220
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1.213.736.1000
157: Region
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 Regional Internet Registry (RIR)
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1: Country code
 US/Canada/Caribbean
Am. Registry for Inet Nos.
 China (86)
242: National/Local
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 NIR or LIR (mostly Asia)
213: Area (city) code
 Beijing (10)
136: Internet Service Provider
 220: Computer/Inet device
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736: Exchange
1000: Number
 DHCP?
 Extension?
 Further addressing
 Further addressing
Static or dynamic
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Static
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Comparing IP Numbers with PSTN
157.242.136.220
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1.213.736.1000
Translated by DNS
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www.lls.edu
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Loyola Law School (LA)
Go to “root server”
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 Where do I find edu directory
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Go to edu directory
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number for Loyola Law Sch
Go to lls.edu (157.242.136.220)
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 What is the IP number for
Go to LLS (1.213.736.1000)
 What is the phone number
Prof. Manheim’s computer?
for Prof. Manheim’s office
Go to Manheim’s computer
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Go to LA book
 What is the main phone
for lls.edu?
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Go to national directory
 Where do I find LA book
 What is the main IP number
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Translated by Phone Book
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Go to Manheim’s phone
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Domain Name System (DNS)
www.lls.edu
TLD (top level domain name)
SLD (second level domain name)
3LD (3d level d. name or computer/internet device)
Root Server
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contains IP #s of all TLD servers
TLD Server
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contains IP #s of all SLD servers (for that TLD)
SLD Server
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contains IP #s of all 3LDs (or Internet devices)
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Types of Top Level Domains
gTLD (generic)
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.com, .net, .org, .name, .biz, .info, .xxx, .eu
.edu, .gov, .mil
ccTLD (country code)
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.us, .uk, .cn
iTLD (international)
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.int (limited to treaty organizations – UN.int)
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Root Servers
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Internet Applications
World Wide Web
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Graphical User Interface (GUI)
 Graphical depiction and formatting of data
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Code: Hyper Text Markup Language (HTML)
 Alt. Codes: XML, Java, Flash, WAP
Email
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Text transport (Client-Server-Inet-Server-Client)
Code: Simple Mail Transport Protocol (SMTP)
 Alt. Codes: MIME, HTML
Other: FTP, Skype, File sharing, ATMs, etc.
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Data
Anything that can be digitized
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Text
Images
Sound
Video
Genetic information
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Putting it all together - Layers
Used by Internet
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HTTP, SMTP, FTP
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MIME, ASCII
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N/A (session timing)
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TCP
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IP
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Ethernet, 802.11
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Cables, hubs, wires
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Who Owns It
There is no “it,” only components
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distributed system w/o centralized control
compare ownership of spectrum
 scarcity vs ubiquity
Components are privately owned
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computers, network components, lines
users may have to pay for use of components
Information on the internet
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may be “owned” (as in intellectual property) or
in the public domain (not owned, or “open”)
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