PPT

HEINZ NIXDORF INSTITUT
University of Paderborn
Algorithms und Complexity
Seminar
Algorithms of the Internet
Christian
Schindelhauer
2004-04-19
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HEINZ NIXDORF INSTITUTE
Motivation
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University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
The Internet
– is the public global wide-area interconnection network for computers
– grows exponentially
– evolves
The evolution of the Internet
• Crises and catastrophes
– Computer hackers since the 70s
– The traffic breakdown in the 80s
– Denial of service attacks in the 90s
– SPAM forever
• Clever algorithmic solutions
– Secure protocols
– TCP bandwidth control
– DoS-detection
– SPAM-filters
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
Goals of the Seminar
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University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
Algorithms of the Internet
Literature recherche in a hot topic
Write an survey on the state of the art
Give a presentation on this field
Interact with others on scientific research
Provide material for
– the community
– future lectures and seminars
– a book
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
Organization
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University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
See the Web-page
http://wwwcs.upb.de/cs/ag-madh/WWW/Teaching/2004SS/AlgInternet/
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Today:
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Next two meetings:
May 10th/17th: 2pm-6pm
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From May to July
July 19th/26th: 1pm-7pm
August 1st (11:59 pm):
August 30th (2pm):
Registration
Assignment of topics
Kickoff and feedback
1st presentation
weekly (voluntary) meetings for consultation
2nd presentation
Deadline for written assignment
Evaluation, grades and comments
(voluntary participation)
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
The Deliverables
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• 1st presentation
– Duration 15 min.
– Presents
• main issue
• strategy to get the work done
• 2nd presentation
– Duration 45 min.
– Survey of the research area
• Written assignment
– 5-10 pages (pure text without title, references, and figures)
– Survey of the most relevant and interesting work in the assigned
area
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
How it Counts for the Grade
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• 1st presentation
– 0%
• 2nd presentation
– 25 %
• Written assignment
– 75 %
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
The Topics
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University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
The mobile Internet
P2P-networks
Web caching
Algorithms for Web search engines
The structure of the Web
Security mechanisms of the Internet
Denial of service attacks
Worms, viruses and spam
Epidemic algorithms
The Domain Name System (DNS)
Bandwidth allocation of TCP
Routing algorithms of IP
Broadcasting and Multicasting in IP
The self-organization of the Internet
“Wild card”
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
Contents of Written Assignment
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University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
Scientific survey on the assigned topic
For broad audience interested in algorithms and Internet
Table of contents for “Tachyonic Networking”
1. What is Tachyonic Network Transmissions (TNT)
2. Applications of TNT
3. How TNT began
4. The main streams of TNT
5. Recent developments in Tachyonic Networking and Computing
6. Focus: The TachyNet - A clever solution of TNT
7. Open problems and upcoming developments
• References
Seminar Algorithms of the Internet
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Format and Layout of Written
Assignment
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HEINZ NIXDORF INSTITUTE
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
American English
Neutral style
5-10 pages (pure text without title, references, and figures)
Accurate and correct citations and references
LATeX, BibTeX
Deliverables
– LATeX source file
– BibTeX file
– Compiled PDF-output
– As many referred text documents as possible
• Electronically if possible
• On paper if necessary
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
1. The Mobile Internet
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University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
IP Tunneling
Mobile Ad-hoc Networks
Handhelds, PDA
UMTS, WAP
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
2. P2P-Networks
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• 1st generation
– Napster, Kazaa, Gnutella
• Modern P2P-Networks
– CAN, CHORD, Tapestry, …
• Visit the lecture “Algorithmen für Peer-to-Peer-Netzwerke”
• But do not copy (all)
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HEINZ NIXDORF INSTITUTE
3. Web Caching
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University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
Relieving hot spots in the Internet
Akamai
Distributed Hash Tables
Take a look into the script “Algorithmische Grundlagen des Internets”,
Summer 2003
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
4. Web Search Engines
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• Commercial systems
– Google, Alltheweb, Altavista, etc
– look at websearchengineshowdown.com
• Algorithmic solutions
– PageRank by Brin and Page (Google)
– Kleinberg’s HITS-algorithm
• Take a look into the script “Algorithmische Grundlagen des Internets”,
Summer 2003 and 2004
• Contact Peter Mahlmann!
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
5. The Structure of the Web
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• The WWW is made by individuals
• Yet the structure can be described by Pareto-distribution
– number of links, size of connected components
• The graph structure of the WWW
• Take a look into the script “Algorithmische Grundlagen des Internets”,
Summer 2002
• Link to Web search machines
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
6. Security mechanisms of the Internet
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• Are there any?
• Is it all trust-based?
• Start your investigations for the search of the missing crypto-layer of
TCP/IP at the secure shell protocol
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
7. Denial of Service Attacks
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• A new problem from the 90s
• Solutions
– Ingress filtering
– Link testing
– Logging
– ICMP Trace back
– Marking (!!!)
• Take a look into the script “Algorithmische Grundlagen des Internets”,
Summer 2003
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
8. Worms, Viruses, and SPAM
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University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
Definition
How they spread
How they work
The perfect Antivirus-Software
An Immune-System for Computers
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HEINZ NIXDORF INSTITUTE
9. Epidemic Algorithms
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• Demers et al.
– Epidemic algorithms for mirroring data bases
– Idea: Spread information like a virus
• Some analyses and new ideas by
– Karp et al. 2001, Randomized Rumor Spreading
• Take a look into the script “Algorithmische Grundlagen des Internets”,
Summer 2002
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
10. The Domain Name System
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University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
What is it?
How does it work?
Why is it so stable?
Alternatives?
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
11. Bandwidth Allocation of TCP
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• Very classical problem of TCP/IP
• Strangely enough network congestion in the Internet is healed in the
transport layer and not in the network layer
• Start with the scripts
– Algorithmische Grundlagen des Internets”, Summer 2002 and 2003
• Random early deletion (RED)
• New TCP-allocation for Tera-Baud-connections
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HEINZ NIXDORF INSTITUTE
12. Routing Algorithms of IP
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• Start with the standard algorithms
• There are lots of theoretical work of routing algorithms
• Concentrate on such algorithms related to IP
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HEINZ NIXDORF INSTITUTE
13. Broadcasting and Multicasting in IP
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University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
IPv4 and IPv6 foresee multicasting
How does it work?
How can it be improved?
Is it possible to have TV on IP?
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUTE
14. The self-organization of the Internet
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• Official organizations of the Internet (IETF, …)
• The Internet and its self-regulation
– socially and technology based
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15. “Wild Card”
HEINZ NIXDORF INSTITUTE
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
• Did we miss something?
• Take a hot topic of your choice within this area.
• If everything fails, I’ll help.
Seminar Algorithms of the Internet
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HEINZ NIXDORF INSTITUT
University of Paderborn
Algorithms und Complexity
Christian Schindelhauer
Thanks and let’s go!
Verteilte Algorithmen in Netzwerken
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