Rahul Tongia, CMU 1
ICT Technology – Issues and Opportunities
Prof. Rahul TongiaSchool of Computer Science
CMU17-899 Fall 2003
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Topics
Trends in Technology Time to update the adage “Cheaper,
Faster, Better – pick any 2”? Internet and Telecommunications
Primer How it works (or doesn’t)
Wireless 802.11 Introduction only Spectrum and other issues
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ICT – To Black Box or Not?
We can cannot cover everything in this one class (even semester!). . .
. . .But the much of the technological issues are not that hard – despite some people wanting to pretend they are.
With a little effort, the important details can be extracted
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Requirements for Successful Service
Technology
Regulation Market
Standards
Can it be built?
Will it sell?Is it allowed?
Will it inter-operate?
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Years to reach 50M users:
0
30
60
90
120
‘22 ‘30 ‘38 ‘46 ‘54 ‘62 ‘70 ‘78 ‘86 ‘94 ‘02
Us
ers
(M
illio
ns
)
Radio TVCable Internet
Source: Morgan Stanley
Radio = 38TV = 13
Cable = 10
Internet = 5
Industry & Society: Penetration Rates
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Year
MIPS
Giga PC
10G PC
Tera PC
100G PC
Doubling every 15 months
Doubling every 2 years
From: Raj Reddy- The Global Village
The Heart of the Matter: The Growth of Computers
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Optical Fiber: Promise & Performance
10 Gb/s
100 Gb/s
1,000Gb/s
1 Gb/s
1978 Projection1978 Projection
1980 Projection1980 Projection
1987 Projection1987 Projection
1995 1995 ProjectionProjection
1983 Projection1983 Projection
Bell Labs
Gilder’s Law – Optical speeds doubling in ~ 9 months
Rahul Tongia, CMU D. Patterson & Kimberly Keeton UCB
Software Challenges in Intelligent Data Processing
38
User Decision Support Demandvs. Processor speed
1
10
100
1996 1997 1998 1999 2000
CPU speed2X / 18 months
Database demand:2X / 9-12 months
Database-Proc.Performance Gap:“Greg’s Law”
“Moore’s Law”
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What Makes the Internet tick? The Internet runs on 3 things:
Boundaries Limits of Responsibilities Inside the core, is like a black box (“The Cloud”)
Standards (protocols) for data-centric design Expectations of how things should work together
Layering Robustness Principle
"Be liberal in what you accept, and conservative in what you send.“ – Jon Postel
Resiliency – distributed architecture Limits Monopolies NO ONE OWNS THE INTERNET
Trust Addressing schemes and registration End-to-end design
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What is the Internet?
The global (public) network built from hundreds and thousands of internetworking independent networks.
No single entity “runs” the Internet
Operates on standards Built on a modified
hierarchical structure Packet Switching
Tier 1
a.k.a. Backbone Providers
Tier 2
Users
• There are often more layers• There can be interconnections other
than at a backbone
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Structures of the Industry
Government Dept. Government company (PTT)
PTT: Abbreviation for postal, telegraph, and telephone (organization). In countries having nationalized services, the organization, usually a governmental department, which acts as its nation's common carrier.
Regulated Monopoly Competition
IXC – Inter Exchange Carriers ILECs – Incumbent Local Exchange Carriers (Baby Bells) CLECs – Competitive Local Exchange Carriers
Overbuilders Unbundled Network Elements (Open Access)
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“Call Completion” / Transaction Charges
Mail – postage stamp mechanism Telephony – cost sharing mechanisms (vary) Internet?
What are the costs? Calling – sharp falls over time Mailing – increasing over time Faxing – not going away anytime soon Email
Is it really free? Access Upstream TCO (ignoring SPAM, for now!) Time
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Peering – Internet “Call Completion”
Where backbones come together Major design issue (relates to cross-
connection) Public Peering – fallout of the public
history of the Internet Network Access Points (NAPs)
Started with 4, but now there are more Usually done by equals
Give as much traffic as receive
Private Peering Commercial (private)
International peering is more limited (links are much more expensive)
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TCP/IP
Suite of protocols for networking Based on logical address for devices Most popular standard worldwide – built
into most OS Like most other packet switching, is
Connectionless Statistical (non-deterministic)
No inherent Quality of Service (QoS) Most of IP routing is unicast
Routers pass packets along towards the destination hop-by-hop
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Internet – Good for what it was made for
Best-effort data network Scalable Resilient
New trend – Everything over IP (XoIP) Voice – Circuit switched
Less than half the traffic Growth of ~25% vs ~100% (?) for data
But, is most of the revenue for carriers Suppliers’ “killer app” For users, email and WWW are the killer apps
(legal, anyways) Internet Telephony is not the same as VoIP
Latency example Berkeley – CMU IP-based lectures!
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Internet is built on trust:
Registration (databases) are believed because people think they are correct Domain Name System
Handles names for humans vs. binary for machines
Root names are the last .xxx, e.g., .com, .edu, .org, .mil, .ca, .tv
Just 13 root servers in the world Many copies made for practical purposes
Borders define responsibilities
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Standards and Regulation Many bodies, sometimes with overlap
IETF (within IAB) handles the engineering of the network
W3C handles web standards such as html, xml, etc. IEEE handles some standards
Requests for Comments (RFCs) are how things get standardized Draft is circulated Modified, debated, etc. (many versions often) Becomes a standard by vote.
Companies often try and tilt emerging standards
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Registries and Domain Names
Numeric address space is coordinated Domain Names initially managed by ISI
(Jon Postel) National Science Foundation (NSF) hired
contractor to administer Network Solutions, Inc. (NSI) [under
InterNIC] NSF stopped paying NSI, allowed NSI to
charge for .com, .net, .org $70 for two years
NSI becomes enormously profitable
* Based on information from Jon Peha and Gary Kessler
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Domain Names (cont.)
NSF responsibilities passed to Commerce Dept. The US government controlled key element of the
Internet (!) so NSF establishes ICANN (Internet Corporation for
Assigned Names and Numbers) in 1998 Has many critics
Registration became competitive by 1999 Registry: manage database, NSI monopoly Registrar: consumer interface, competition
IP address space (numeric) is still from regional authorities
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Spectrum
Frequency affects
Capacity Bandwidth
Range Interference
and Line of Sight Requirements
Protocols and Technology
ISM Bands are kept free for Industrial, Scientific, and Medical Applications, e.g., 2.4 GHz
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Special Properties of Spectrum
Heavily controlled Military uses Licensed use
Source of licensing fees Is a public good; everywhere yet
not limitless Many forms are appropriate for
point to multipoint (including broadcast)
Encoding is key – bits per hertz
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Spectrum Issues
802.11 Alphabet Soup a, b, g, i, etc. – Differ in
Data Rates Bands Compatibility Distance
Is licensed spectrum better (cleaner, scalable, etc.)? 3G licenses have gone for thousands of
dollars per potential subscriber Cognitive Radios might be the future
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Hypothetical WiFi Kiosk
Access Points are now about $100 (only!) What else does it take? What range does it cover?
Number of Users Band overlaps and congestion
FCC vs. ETSI regulations on emissions Uplinking
IP address space “Now What” Syndrome – need user h/w, s/w,
etc. Business Plan ?
Capex is less than half of “broadband” costs
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ICT Issues
Policy Convergence Open Access
Universal Service / Digital Divide Globalization
“Winner Takes All” Internet
Is it special (Information Service vs. Telecom Service)?
Jurisdiction Taxation
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Issues in the Internet
Scalability Internet is growing* at 100-300% Running out of IP addresses – esp. LDCs
Long term solution: IPv6 128 bit addresses (millions per square meter)
Protocols and equipment are straining Security
Distributed Denial of Service – example of an attack
Viruses Spam Privacy
Quality of Service Voice