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Introduction to Networks and Security: Lecture 14 - Fall 2002

This lecture covers advanced networking topics such as integrated services, multicast, denial of service attacks, peer-to-peer networking, ad-hoc networking, and active networking.

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Introduction to Networks and Security: Lecture 14 - Fall 2002

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  1. CSE331:Introduction to Networksand Security Lecture 14 Fall 2002

  2. Announcements • Midterm on Wednesday • Project 1 due today • Email submissions to achadha@gradient.cis.upenn.edu CSE331 Fall 2002

  3. Today • Wrap up discussion of networks • Quality of service • Advanced Networking • Ethereal • Review for Exam CSE331 Fall 2002

  4. Integrated Services (RSVP) • Proposed in 1995-1997 • Service Classes • Guaranteed arrival service • For delay intolerant applications • Guarantee a maximum delay • Controlled Load • For loss tolerant, adaptive applications • Emulate lightly loaded network CSE331 Fall 2002

  5. Implementation Mechanisms • Flowspecs • Describe the kind of service needed • “I need maximum delay of 100ms” • “I need to use controlled load service” • Admission Control • Network decides whether it can provide the desired service • Resource Reservation Protocol (RSVP) • Mechanism to exchange info about requests • Soft state approach • Packet Scheduling • Manage queuing and scheduling. CSE331 Fall 2002

  6. Advanced Networking Topics • Multicast • Send the same message to a collection of receivers • How to do so efficiently? • Multicast trees CSE331 Fall 2002

  7. (Distributed) Denial of Service • Flood a server with bogus requests • TCP SYN packet flood • Up to 600,000 packets per second • Uses up server’s resources, causing legitimate users to be denied service • Detection & Assessment? • 12,800 attacks at 5000 hosts in 3 week period! • IP Spoofing (forged source IP address) • http://www.cs.ucsd.edu/users/savage/papers/UsenixSec01.pdf • Prevention? • Filtering? • Decentralized file storage? CSE331 Fall 2002

  8. Peer-to-Peer networking • Gnutella – distributed file sharing • (Unlike Napster, which uses centralized servers) • Freenet • Anonymous, decentralized file storage • Distributed storage infrastructure • PAST (Rice and Microsoft Research, routing substrate - Pastry) • OceanStore (U.C.Berkeley, routing substrate - Tapestry) • Publius (AT&T) • Farsite (Microsoft Research) • CFS (MIT, routing substrate - Chord) • GRCD(UC Berkeley, builds on CAN) CSE331 Fall 2002

  9. Ad-hoc Networking • Wireless Networks • No fixed structure • How to do routing? • Grid Project http://www.pdos.lcs.mit.edu/grid/ • Make use of Geographic data CSE331 Fall 2002

  10. Active Networking • Treat packets as programs • The programs • Specify routing requests • Can check link state • Can make decisions based on network conditions • Routers interpret these active packets • Penn’s switchware project • http://www.cis.upenn.edu/~switchware/ CSE331 Fall 2002

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