Transcript History and technical background

Internet Policy
Day 1 - Workshop Session No. 1
History and technical background
Prepared for CTO by Link Centre, Witwatersrand
University, South Africa
Sessions Summary
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Day 1
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Governance processes
Interconnection and exchanges
Session 5
Session 6
The impact of telecommunications regulation
Internet specific policy issues
Day 4
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Session 3
Session 4
Day 3
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History and technical background
Market structure
Day 2
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Session 1
Session 2
Session 7
Session 8
Content on the Internet
E-commerce issues
Day 5
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Session 9
Session 10
Internet tools for regulators
Conclusion, review and evaluation
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
History and technical background
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The purpose of this session is to
understand the basic design and functioning
of the networks which make up the
Internet.
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
Topics of discussion
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How did the Internet develop?
What kind of network is the Internet?
Packet-based networks
Backbone infrastructure
Basic Internet protocol (TCP/IP)
IP addresses
How does data get from A to B?
Infrastructure: Routers, Switches and Servers
Higher level protocols
Domain names
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
How did the Internet develop?
ARPANET (military) [1969 – 1980’s]:
 Research sponsored by the US Dept. of Defense,
specifically, the Advanced Research Projects
Agency (ARPA)
 Objective was to link geographically distant
computers to allow remote access and sharing of
data
 Network had to have no single point of failure
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
How did the Internet develop?
ARPANET (military) [1969 – 1980’s]:
 The Internet’s Grandfather, ARPANET, was born in
late 1969
 From the beginning ARPANET was packet-based,
which has important ramifications on its
operation (no single point of failure)
 Initially used NCP (Network Control Protocol),
but adopted TCP/IP from 1973 onwards.
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
How did the Internet develop?
NSFNet (academia) [1980’s – 1991]
 By the mid-80’s ARPANET had grown into a
widespread educational and scientific network
 Started to expand to other countries
 The backbone of this network (NSFNet) was
funded by the National Science Foundation (NSF)
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
How did the Internet develop?
NSFNet (academia) [1980’s – 1991]
 Because it was government-funded, there
remained restrictions on the commercial use of
this backbone until 1991
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
How did the Internet develop?
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
How did the Internet develop?
ISPs and Telcos (business) [1991-2001]
 In the late eighties and early nineties, the
backbone was commercialised and the
Internet has grown exponentially since then
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
What kind of network is the Internet?
The word “internet”
 network = interconnected computers
 internet = inter connected networks
(archaic :-)
 Internet = The Internet
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
What kind of network is the Internet?
Types of networks
 Circuit-based networks
– Telephone networks
– Power grids
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Packet-based networks
– Post Office
– The Internet
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
Packet-based networks
 Unlike
circuit-based networks, packet
networks have no dedicated end-to-end
connection
 A characteristic of these networks is the
unpredictable nature of routing
 The Post Office runs a packet-based
network
 The Internet is packet-based
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
Backbone Infrastructure
 Copper
cable
 Fibre-optic cable
 Wireless
 Satellite (VSAT)
 “Broadband”
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
Basic Internet protocols (TCP/IP)
 TCP/IP
=
Transmission
Control Protocol /
Internet Protocol
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
IP addresses
 Numbers
– IP addresses
– IP numbers currently consist of four 8-bit
numbers (e.g. 209.212.117.130)
– We are running out of these numbers, hence
the introduction of IP version 6
– IP -- what version are you using? (version 4)
– NAT = Network Address Translation
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
How does data get from A to B?
 The
transmission process is roughly as
follows:
– Data is split up into IP packets (TCP’s job)
– Variable packet size
– The destination of the packets are clearly
labeled (IP address)
– The packets are dumped into the closest part
of the network to fend for themselves
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
Internet infrastructure: Routers,
Switches and Servers
Bigger blocks
 Routers
– routers direct TCP/IP packets to their destinations
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Switches
– Tend to be simpler and faster than routers
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Servers
– servers answer requests for information and serve
information to others
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Speed
– A connection is only as fast as its slowest link!
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
Higher level protocols
Other protocols
 TCP/IP is the basis for moving packets of data on
the Internet, but that is all it does
 On top of this, different protocols are run to
provide useful services or functions
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HTTP = Hyper Text Transfer Protocol (web)
SMTP = Simple Mail Transfer Protocol (e-mail)
POP3 = Post Office Protocol
BGP = Border Gateway Protocol
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
Domain names
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Names versus numbers
– Recap: IP addresses (e.g. 109.212.117.130)
– Humans are not good at remembering numbers, so
domain names were created
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Generic versus geographic
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Generic: .com, .net, .org
Special: .gov, .mil, .edu
Little known domains: .int
Country code: .uk, .za, .jp
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further split up, e.g. .co.za, .org.za, .gov.za.
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
Domain names
 New
domains
– Generic: .biz and .info
– Special: .museum and .aero
 “New”
domains
– .tv, .nu, .to, etc.
CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
Summary
The Internet has had military, academic and
commercial influences
 Different media (copper, fibre, wireless) are used
for the Internet backbone
 The Internet uses TCP/IP packets
 IP addresses and domain names are used as
identifiers
 Routers and switches move packets
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CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002
Quiz
What does NCP stand for?
 What was the National Science Foundation’s
backbone network called?
 What year were commercial restrictions on the
Internet backbone dropped?
 What does BGP stand for?
 What version of IP are we using now?
 How many countries are not connected to the
Internet?
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CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002