Internet Policy Day 1 - Workshop Session No. 1 History and technical background Prepared for CTO by Link Centre, Witwatersrand University, South Africa

Internet PolicyDay 1 - Workshop Session No. 1

History and technical background

Prepared for CTO by Link Centre, Witwatersrand University, South Africa

CTO / DFID Internet Policy workshop, Jamaica, 22-26 April 2002

Sessions Summary Day 1

– Session 1 History and technical background– Session 2Market structure

Day 2– Session 3Governance processes– Session 4Interconnection and exchanges

Day 3– Session 5The impact of telecommunications regulation– Session 6Internet specific policy issues

Day 4– Session 7Content on the Internet – Session 8E-commerce issues

Day 5– Session 9Internet tools for regulators– Session 10 Conclusion, review and evaluation


History and technical background

The purpose of this session is to understand the basic design and functioning of the networks which make up the Internet.


Topics of discussion

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


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



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.



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)



NSFNet (academia) [1980’s – 1991] Because it was government-funded,

there remained restrictions on the commercial use of this backbone until 1991





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


What kind of network is the Internet?

The word “internet” network = interconnected

computers internet = inter connected

networks (archaic :-) Internet = The Internet


What kind of network is the Internet?

Types of networks Circuit-based networks

– Telephone networks– Power grids

Packet-based networks– Post Office– The Internet


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


Backbone Infrastructure

Copper cable Fibre-optic cable Wireless Satellite (VSAT) “Broadband”


Basic Internet protocols (TCP/IP)

TCP/IP = Transmission Control Protocol / Internet Protocol


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


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


Internet infrastructure: Routers, Switches and

ServersBigger blocks Routers

– routers direct TCP/IP packets to their destinations Switches

– Tend to be simpler and faster than routers Servers

– servers answer requests for information and serve information to others

Speed – A connection is only as fast as its slowest link!


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– HTTP = Hyper Text Transfer Protocol (web) – SMTP = Simple Mail Transfer Protocol (e-mail) – POP3 = Post Office Protocol– BGP = Border Gateway Protocol


Domain names

Names versus numbers – Recap: IP addresses (e.g. 109.212.117.130)– Humans are not good at remembering

numbers, so domain names were created Generic versus geographic

– Generic: .com, .net, .org – Special: .gov, .mil, .edu– Little known domains: .int– Country code: .uk, .za, .jp

further split up, e.g. .co.za, .org.za, .gov.za.


Domain names

New domains– Generic: .biz and .info – Special: .museum and .aero

“New” domains– .tv, .nu, .to, etc.


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


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?

Documents

Internet Policy Day 1 - Workshop Session No. 1 History and technical background Prepared for CTO by Link Centre, Witwatersrand University, South Africa