CSMA/CD Stations, Total Traffic) X • 802.4 -- Token Bus a • 802.5 -- Token Ring Q • Other Committees: FDDI, Metropolitan Area Nets, Security M

Total Page:16

File Type:pdf, Size:1020Kb

CSMA/CD Stations, Total Traffic) X • 802.4 -- Token Bus a • 802.5 -- Token Ring Q • Other Committees: FDDI, Metropolitan Area Nets, Security M Interconnection Protocols Interconnection Protocols Purpose of Course Good Ideas • Understand generic problems and approaches • Parameters (e.g., how often to send hellos) • Less important (for this course) but covered should be settable at nodes one at a time somewhat: description of what happens to be without having to reset the whole network implemented • How can you ensure that two nodes have compatible parameters? • Some changes are “compatible” in that they can be added to nodes one at a time without disrupting operations. • How can you design messages so that you can add fields in the future and still interoperate with old nodes? 1 2 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols Another Distance Vector Link Costs Trick • Some think it’s a good idea for the cost of the • Double metric: hops and cost link to vary according to congestion. - - allows routes to be chosen based on “real” route around congestion metric (allowing slow links to have higher - don’t have to configure link costs costs) • I don’t - detects unreachable destinations (with path - extra routing control traffic lengths more than 15) just as quickly - less time the network is in a converged state - can’t react quickly enough to matter 3 4 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols IEEE 802 What is a LAN? Chartered to standardize LANs Badly defined term (typical in this field) Took their job very seriously -- standardized lots Assumed general characteristics: of LANs • multiaccess • logical full connectivity • 802.1 -- management, interconnection • multicast/broadcast capability • 802.2 -- SAPs, LLC • limited scalability (distance, number of • 802.3 -- CSMA/CD stations, total traffic) X • 802.4 -- Token bus A • 802.5 -- Token ring Q • Other committees: FDDI, Metropolitan area nets, security M 5 6 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols What is Multicast? Taking Turns • Unicast: Alice sends to Bob • Suppose there’s a shared medium (like the • But, on a LAN, everyone can hear, so if they’re room we’re in). If more than one speaker, just not Bob, they discard the packet hear garbage • • The hardware has to be smart to filter out Old kinds had a master that polled the “slaves” traffic not intended for this node (so as not to - “Alice, do you have anything to send?” bother the node with all the interrupts) - Alice “Terminal 23 typed ‘Gree’” • But sometimes you want to send to a group of - “Amy, I’m sending 315 to you. Anything to nodes. Use the natural ability of the LAN! send?” - to send to a group of nodes...tell them all to - listen to address X (in addition to their own address). Then transmit to X and they’ll all - “Andy do you have anything to send?” receive it - Fancier protocols poll recently active • “Promiscuous” listen means you tell your chip stations more frequently to send everything to you. - Could have 2 slaves talking directly, but only if 2 addresses in header 7 8 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols CSMA/CD (Ethernet) The “CD” in CSMA/CD - Carrier Sense Multicast Access with • Speed of light: “It’s not just a good idea. It’s Collision Detect. the law” - Single “bus” on which all stations reside. If • Suppose packet very small. May not detect anyone transmits, everyone hears collision - Intended for peer-to-peer (not master to • Maximum length of bus (maximum delay, slaves) including repeaters), and minimum sized - To transmit: If link idle, transmit. Check for packet so guaranteed to detect delay. collision. If collision, back off a random amt. • Packet size must be twice length of cable in If again a collision, back off a random amt order for sender to know it hasn’t collided! chosen from a double-sized interval, etc., (why?) until max collisions. Then give up on that • Hub: Multi-port repeater packet, but next packet start from small interval again “exponential backoff” - Many variants 9 10 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols Token Ring Token Rings, Continued C B D • Transmitter removes frame from ring (why?) A E • Slower rings (802.5) tend to have one frame at I a time H F • Faster rings (e.g., FDDI) have a train of G packets followed by the token • Idea simple, but made much more complicated • Just a bunch of point-to-point links with priorities • Want to minimize delay around the circle • Minimum delay: one bit per station • “token” can be turned into “start of packet” by flipping one bit • Token travels around ring. To transmit, when see token, flip bit, transmit packet • Two “ack” bits: A=address recognized, C=frame copied 11 12 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols Token Bus Which is best? • Like Ethernet, everything on one wire • For awhile, hotly debated • Complicated protocol for building a logical • These days, all of them dying out! (I’ll show ordering of active stations you what “Ethernet” is these days in a later • Each active station must know predecessor, lecture) successor • When get token, send packet (if you have one), then transmit token to successor • Periodically, invite other stations to join the ring (between you and your successor) • VERY complex protocol for doing that 13 14 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols IEEE802 Addresses Address Issues • Idea: unique ID for each IEEE802 device • How do you write down an address? OUI - canonical written form: 43-75-cf-5f-45-7a • Transmitted on 802.3 or 802.4 LSB first group/individual 01000011 01110101 11001111 01011111 01000101 01111010 globally/locally assigned 24 • Transmitted on 802.5 MSB first • Assigned in blocks of 2 • Given 23 byte constant (Organizationally 11000010 10101110 11110011 11111010 10100010 01011110 Unique Identifier), plus group/individual bit • All 1’s intended to mean “broadcast”, i.e., • Group/individual bit supposed to be first bit “everyone”, which is nonsense. Really each transmitted protocol should use its own multicast address • Different bit order very annoying to mean all nodes that speak that protocol 15 16 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols EUI-48/EUI-64 Multi-Lingual Environments • EUI-48 is the 6-byte address already discussed • EUI-64 is IEEE’s new 8-byte address. • You can speak lots of things (IP, CLNP, IPX, • How much should be OUI? AppleTalk, etc.) • - 5 byte OUI, virtually unlimited number of Someone hands you a pile of bits. What is it? OUIs, 224 addresses per block - Maybe we were careful -- yeah, right - 3 byte OUI, virtually unlimited number of - Maybe we were lucky -- yeah, right addresses per OUI, but 22 bits (4 million) • Conclusion: not enough information in the OUIs packet header to differentiate -- need an extra - Consequence of too small block...some field in the data link header to say what it is people need to come back for more blocks - protocol type: well-known (globally - Consequence of too small OUI...run out of administered) values, one field in header OUIs, world ends - SAP (service access point) or socket: locally - They kept 3-byte OUI, but with plea to not administered, one for destination, one for ask for more OUIs until you’ve used up all source your addresses 17 18 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols Packet HDRs on CSMA/CD How the SAPs work • Notice the “global/local” bit -- those SAPs are globally assigned! If you are a very privileged Ethernet protocol, and obtain one of these, you’d set DSAP=SSAP= your assigned SAP value 6 6 2 46-1500 4 • dest src p-t DATA fcs How does it work if you’re not a privileged protocol? Uh... 802.3 • World class kludge -- get a SAP value assigned 6 6 2 1 1 1 43-1497 4 to mean “underprivileged protocol”. That was dest src ln dsap ssap ctl data fcs done. It’s called SNAP SAP (SubNetwork Access Protocol), and it = aa hex. Format of SAP • If DSAP=SSAP=aa hex, then after CTL is a protocol type field G/L G/I • The protocol type is 5 bytes long • Convention: 0.0.0.protocol type allows 2 octet Ethertypes to fit into 5 octets 19 20 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols Converting between 802.3 Why Bridges? and Ethernet • LANs don’t scale - Distance Ethernet - Number of stations 6 6 2 46-1500 - Traffic dest src X DATA • Want to glue LANs together 802.3 • Want local traffic to stay local 6 6 2 1 1 1 5 43-1497 dest src ln AA AA 3 0.0.0.X data AC D 21 22 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols Two Types of Bridges Transparent Bridge • Design constraint: work with unmodified • Two types stations, designed to work on single LAN - Transparent (also known as spanning tree) - Source routing • Transparent standardized by 802.1 • Source routing originally adopted by 802.5 AC D when it lost out to transparent bridges in 802.1 • Packet contains two interesting fields: - destination - source • Learn based on source field • Forward based on destination field • When in doubt, forward 23 24 Copyright © 2001 Radia Perlman Copyright © 2001 Radia Perlman Interconnection Protocols Interconnection Protocols Multiple
Recommended publications
  • Digital Technical Journal, Number 3, September 1986: Networking
    Netwo;king Products Digital TechnicalJournal Digital Equipment Corporation Number 3 September I 986 Contents 8 Foreword William R. Johnson, Jr. New Products 10 Digital Network Architecture Overview Anthony G. Lauck, David R. Oran, and Radia J. Perlman 2 5 PerformanceAn alysis andModeling of Digital's Networking Architecture Raj Jain and William R. Hawe 35 The DECnetjSNA Gateway Product-A Case Study in Cross Vendor Networking John P:.. �orency, David Poner, Richard P. Pitkin, and David R. Oran ._ 54 The Extended Local Area Network Architecture and LANBridge 100 William R. Hawe, Mark F. Kempf, and Alan). Kirby 7 3 Terminal Servers on Ethernet Local Area Networks Bruce E. Mann, Colin Strutt, and Mark F. Kempf 88 The DECnet-VAXProduct -A n IntegratedAp proach to Networking Paul R. Beck and James A. Krycka 100 The DECnet-ULTRIXSoftware John Forecast, James L. Jackson, and Jeffrey A. Schriesheim 108 The DECnet-DOS System Peter 0. Mierswa, David). Mitton, and Ma�ha L. Spence 117 The Evolution of Network Management Products Nancy R. La Pelle, Mark). Seger, and Mark W. Sylor 129 The NMCCjDECnet Monitor Design Mark W. Sylor 1 Editor's Introduction The paper by Bill Hawe, Mark Kempf, and AI Kirby reports how studies of potential new broad­ band products led to the development of the Extended LAN Architecture. The design of the LANBridge 100, the first product incorporating that architecture, is described, along with the trade-offs made to achieve high performance. The speed of communication between terminals and systems depends on how they are connected. Bruce Mann, Colin Strutt, and Mark Kempf explain how they developed the LAT protocol to connect terminals to hosts on an Ethernet.
    [Show full text]
  • Harvard University
    HARVARD UNIVERSITY ROBERT AND RENÉE BELFER CENTER FOR SCIENCE AND INTERNATIONAL AFFAIRS 2000-2001 ANNUAL REPORT 2 Robert and Renée Belfer Center for Science and International Affairs 2000-2001 Annual Report Director’s Foreword 5 Overview From the Executive Director 7 Environment and Natural Resources Program TABLE 8 OF Harvard Information Infrastructure Project 52 CONTENTS International Security Program 71 Science, Technology and Public Policy Program 109 Strengthening Democratic Institutions Project 155 WPF Program on Intrastate Conflict, Conflict Prevention, and Conflict Resolution 177 Events 188 Publications 219 Biographies 241 Robert and Renée Belfer Center for Science and International Affairs 3 2000-2001 Annual Report 4 Robert and Renée Belfer Center for Science and International Affairs 2000-2001 Annual Report Director’s Foreword —————————————♦ For the hub of the John F. Kennedy School’s research, teaching, and training in international security affairs, environmental and resource issues, conflict prevention and resolution, and science and technology policy, the first academic year of the new century has been bracing. According to our mission statement, The Belfer Center for Science and International Affairs strives to provide leadership in advancing policy-relevant knowledge about the most important challenges of international security and other critical issues where science, technology, and international affairs intersect. BCSIA’s leadership begins with the recognition of science and technology as driving forces transforming threats and opportunities in international affairs. The Center integrates insights of social scientists, technologists, and practitioners with experience in government, diplomacy, the military, and business to address critical issues. BCSIA involvement in both the Republican and Democratic campaigns. BCSIA was privileged to have senior advisors in both camps in one of the most unforgettable American elections in recent memory.
    [Show full text]
  • Thoughts About Network Protocols and the Internet
    Thoughts about Network Protocols and the Internet Radia Perlman Dell EMC [email protected] 1 Most important point I’ll make 2 Most important point I’ll make • Not everything you read, or hear is true 3 How networking tends to be taught • Memorize these standards documents, or the arcane details of some implementation that got deployed • Nothing else ever existed • Except possibly to make vague, nontechnical, snide comments about other stuff 4 My philosophy on teaching (and books) • Look at each conceptual problem, like how to autoconfigure an address • Talk about a bunch of approaches to that, with tradeoffs • Then mention how various protocols (e.g., IPv4, IPv6, Appletalk, IPX, DECnet, …) solve it 5 But some professors say… • Why is there stuff in here that my students don’t “need to know”? 6 Where does confusion come from? • Hype • People repeating stuff • Buzzwords with no clear definition – Or persons A and B have a clear definition in mind, but different from each other • Or the world changing, so something that used to be true is no longer true 7 Things are so confusing • Comparing technology A vs B – Nobody knows both of them – Somebody mumbles some vague marketing thing, and everyone repeats it – Both A and B are moving targets 8 Standards Bodies… 9 What about “facts”? • What if you measure A vs B? 10 What about “facts”? • What if you measure A vs B? • What are you actually measuring?...one implementation of A vs one implementation of B 11 What about “facts”? • What if you measure A vs B? • What are you actually measuring?...one
    [Show full text]
  • Myths, Missteps, and Folklore in Protocol Design
    Sun Laboratories 2000-0058 Myths, Missteps, and Folklore in Protocol Design Radia Perlman Sun Labs, East Coast [email protected] 1 Radia Perlman Sun Laboratories 2000-0058 Outline • Bridges, Routers, and Switches, Oh My! • What’s with IP Multicast? • What’s with IPv6? • ARPANET flooding • BGP • Compatible Parameters • Forward Compatibility • How not to get any advantage from a public key system 2 Radia Perlman Sun Laboratories 2000-0058 Why This Talk? • Learn from mistakes • Understand oddities in today’s protocols • Counteract “religion” aspect “It’s not what you don’t know that’ll get you. It’s what you do know that ain’t true” ..............Mark Twain • Be provocative. Start lively discussion. 3 Radia Perlman Sun Laboratories 2000-0058 Bridges and Routers and Switches, Oh My! • ISO’s OSI Reference Model - layer 1: physical - layer 2: neighbor-neighbor - layer 3: talk across cloud via a multi-hop path - layer 4: end-to-end - layer 5 and above: boring • Repeater: layer 1 relay • Bridge: layer 2 relay • Router: layer 3 relay • OK. Why is there such a thing as a layer 2 relay? 4 Radia Perlman Sun Laboratories 2000-0058 Definition of Layer 2 Protocol: Anything defined by a committee whose charter is to standardize a layer 2 protocol. What does a (connectionless) layer 3 protocol look like? • put “envelope” on your data that includes destination, source address and hop count • Layer 3 addresses usually hierarchical location node • With point-to-point links, only need one set of addresses: ultimate source, and ultimate destination • With multi-access links like Ethernet, need “next hop” also 5 Radia Perlman Sun Laboratories 2000-0058 Ethernet • Need “next hop” address in addition to ultimate destination A δ φ R1β R2 R3 α ε S π D layer 2 layer 3 α src= src=S data dst=β dst=D δ src= src=S data dst=φ dst=D ε src= src=S data dst=π dst=D • Also required rethinking routing algorithm (e.g., Designated Routers, pseudonodes) 6 Radia Perlman Sun Laboratories 2000-0058 What are Bridges? • Myth: Bridges were invented before routers.
    [Show full text]
  • List of Internet Pioneers
    List of Internet pioneers Instead of a single "inventor", the Internet was developed by many people over many years. The following are some Internet pioneers who contributed to its early development. These include early theoretical foundations, specifying original protocols, and expansion beyond a research tool to wide deployment. The pioneers Contents Claude Shannon The pioneers Claude Shannon Claude Shannon (1916–2001) called the "father of modern information Vannevar Bush theory", published "A Mathematical Theory of Communication" in J. C. R. Licklider 1948. His paper gave a formal way of studying communication channels. It established fundamental limits on the efficiency of Paul Baran communication over noisy channels, and presented the challenge of Donald Davies finding families of codes to achieve capacity.[1] Charles M. Herzfeld Bob Taylor Vannevar Bush Larry Roberts Leonard Kleinrock Vannevar Bush (1890–1974) helped to establish a partnership between Bob Kahn U.S. military, university research, and independent think tanks. He was Douglas Engelbart appointed Chairman of the National Defense Research Committee in Elizabeth Feinler 1940 by President Franklin D. Roosevelt, appointed Director of the Louis Pouzin Office of Scientific Research and Development in 1941, and from 1946 John Klensin to 1947, he served as chairman of the Joint Research and Development Vint Cerf Board. Out of this would come DARPA, which in turn would lead to the ARPANET Project.[2] His July 1945 Atlantic Monthly article "As We Yogen Dalal May Think" proposed Memex, a theoretical proto-hypertext computer Peter Kirstein system in which an individual compresses and stores all of their books, Steve Crocker records, and communications, which is then mechanized so that it may Jon Postel [3] be consulted with exceeding speed and flexibility.
    [Show full text]
  • Lecture 9: Networks to Internetworks
    Lecture 9: Networks to Internetworks CSE 123: Computer Networks Aaron Schulman HW 1 due today Lecture 9 Overview ! Bridging & switching (cont.) u Spanning Tree ! Internetworking u Routing u Internet Protocol CSE 123 – Lecture 8: From networks to Internetworks 2 Spanning Tree A ! Spanning tree uses B subset of bridges so B3 there are no cycles C B5 u Prune some ports D B7 B2 K u Only one tree E F B1 ! Q: How do we find a spanning tree? G H u Automatically! B6 B4 u Elect root, find paths I J CSE 123 – Lecture 9: From networks to Internetworks 3 Spanning Tree Algorithm ! Each bridge sends periodic configuration messages u (RootID, Distance to Root, BridgeID) u All nodes think they are root initially ! Each bridge updates route/Root upon receipt u Smaller root address is better u Select port with lowest cost to root as “root port” u To break ties, bridge with smaller address is better ! Rebroadcast new config to ports for which we’re “best” u Don’t bother sending config to LANs with better options u Add 1 to distance, send new configs on ports that haven’t told us about a shorter path to the root ! Only forward packets on ports for which we’re on the shortest path to root (prunes edges to form tree) CSE 123 – Lecture 9: From networks to Internetworks 4 Spanning Tree Example ! Sample messages to and from B3: A B B3 1. B3 sends (B3, 0, B3) to B2 [LAN C] and B5 [LAN A] C B5 2.
    [Show full text]
  • Advanced Computer Networks Cs 538 Fall 2011
    Advanced Computer Networks cs 538 fall 2011 Brighten Godfrey [email protected] Fall 2011 slides ©2010-2011 by Brighten Godfrey except photographs (from Computer History Museum) and unless otherwise noted To d ay Course Overview Internet History Your Future This course • is instructed by Brighten Godfrey ([email protected], 3128 Siebel) • takes place Tue & Thu, 3:30 - 4:45 pm, in 1302 Siebel • comes with FREE office hours: currently, Tuesdays after class and by appointment • has a web site: http://www.cs.illinois.edu/~pbg/ courses/cs538fa11/ Your instructor • Ph.D. from UC Berkeley, 2009 • Dissertation on improving resilience and performance of distributed systems by taking advantage of heterogeneity • Research interests: • Reliable, flexible, and efficient networked systems • Algorithms for and analysis of distributed systems Course goal • Prepare ourselves to perform high-quality research advancing the field of networking Course components • Networking literature • The classics • The challenges • The latest • Research project • How to read, criticize, and present research Major topics • Core architecture • Classic Internet architecture • Congestion control • Forwarding • Routing • Naming • Making it work well • Reliability, scalability, selfishness, security • Domain-specific networks • Enterprise, data center, P2P, wireless Requirements & grading • Project (45%) • Midterm presentation (10%) • Final paper (20%) • Final poster presentation (15%) • Assignments, quizzes (15%) • Paper reviews (15%) • Paper presentations (15%) • Class participation
    [Show full text]
  • Computer Networking: a Top-Down Approach, 7Th Edition
    Computer Networking A Top-Down Approach Seventh Edition James F. Kurose University of Massachusetts, Amherst Keith W. Ross NYU and NYU Shanghai Boston Columbus Indianapolis New York San Francisco Hoboken Amsterdam Cape Town Dubai London Madrid Milan Munich Paris Montréal Toronto Delhi Mexico City São Paulo Sydney Hong Kong Seoul Singapore Taipei Tokyo Vice President, Editorial Director, ECS: Marcia Horton Acquisitions Editor: Matt Goldstein Editorial Assistant: Kristy Alaura Vice President of Marketing: Christy Lesko Director of Field Marketing: Tim Galligan Product Marketing Manager: Bram Van Kempen Field Marketing Manager: Demetrius Hall Marketing Assistant: Jon Bryant Director of Product Management: Erin Gregg Team Lead, Program and Project Management: Scott Disanno Program Manager: Joanne Manning and Carole Snyder Project Manager: Katrina Ostler, Ostler Editorial, Inc. Senior Specialist, Program Planning and Support: Maura Zaldivar-Garcia Cover Designer: Joyce Wells Manager, Rights and Permissions: Ben Ferrini Project Manager, Rights and Permissions: Jenny Hoffman, Aptara Corporation Inventory Manager: Ann Lam Cover Image: Marc Gutierrez/Getty Images Media Project Manager: Steve Wright Composition: Cenveo Publishing Services Printer/Binder: Edwards Brothers Malloy Cover and Insert Printer: Phoenix Color/ Hagerstown Credits and acknowledgments borrowed from other sources and reproduced, with ­permission, in this textbook appear on appropriate page within text. Copyright © 2017, 2013, 2010 Pearson Education, Inc. All rights reserved. Manufactured in the United States of America. This publication is protected by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permissions, request forms and the appropriate contacts within the Pearson Education Global Rights & Permissions Department, please visit www.pearsoned.com/permissions/.
    [Show full text]
  • Introduction to TRILL by Radia Perlman, Intel Labs, and Donald Eastlake, Huawei Technologies
    September 2011 Volume 14, Number 3 A Quarterly Technical Publication for From The Editor Internet and Intranet Professionals I recently attended a conference in Japan where the attendee network offered IPv6 service only. In the past, conferences such as the Asia In This Issue Pacific Regional Conference on Operational Technologies (APRICOT) and meetings of the Internet Engineering Task Force (IETF) have conducted IPv6 experiments, but these have all been “opt-in” events. From the Editor ...................... 1 The conference in Japan was different: there was no IPv4 service available. Making this work involved a few manual configuration TRILL ..................................... 2 steps, but for the most part everything worked more or less the same as it did under IPv4. Some applications, including my instant message client and Skype did not work, and all connections to IPv4-only hosts IP Backhaul ........................... 21 needed to use Fully Qualified Domain Names (FQDNs) instead of IP addresses, but overall the experience gave me confidence that IPv6 is becoming a reality. As you might expect, this IPv6-only experiment Fragments ............................. 30 also uncovered a number of bugs and incompatibilities that were duly reported to developers around the world. Call for Papers ...................... 31 Our first article is an overview of TRansparent Interconnection of Lots of Links (TRILL). TRILL uses Layer 3 routing techniques to create a large cloud of links that appear to IP nodes to be a single IP subnet. The protocol has been developed in the IETF and is currently being refined and enhanced in the TRILL working group. The article is by Radia Perlman and Donald Eastlake.
    [Show full text]
  • Principles of Computer System Design an Introduction
    Principles of Computer System Design An Introduction Suggestions for Further Reading Jerome H. Saltzer M. Frans Kaashoek Massachusetts Institute of Technology Version 5.0 Saltzer & Kaashoek Ch. 11, p. i June 24, 2009 12:32 am Copyright © 2009 by Jerome H. Saltzer and M. Frans Kaashoek. Some Rights Reserved. This work is licensed under a Creative Commons Attribution-Non­ commercial-Share Alike 3.0 United States License. For more information on what this license means, visit http://creativecommons.org/licenses/by-nc-sa/3.0/us/ Designations used by companies to distinguish their products are often claimed as trade­ marks or registered trademarks. In all instances in which the authors are aware of a claim, the product names appear in initial capital or all capital letters. All trademarks that appear or are otherwise referred to in this work belong to their respective owners. Suggestions, Comments, Corrections, and Requests to waive license restrictions: Please send correspondence by electronic mail to: [email protected] and [email protected] Saltzer & Kaashoek Ch. 11, p. ii June 24, 2009 12:32 am Suggestions for Further Reading CHAPTER TABLE OF CONTENTS Introduction................................................................................... SR–2 1 Systems ..................................................................................... SR–4 1.1 Wonderful books about systems ............................................... SR–4 1.2 Really good books about systems. ............................................ SR–6 1.3 Good books on related
    [Show full text]
  • Antonio Tajani MEP President of the European Parliament [email protected]
    Antonio Tajani MEP President of the European Parliament [email protected] 12 June 2018 Mr President, Article 13 of the EU Copyright Directive Threatens the Internet As a group of the Internet’s original architects and pioneers and their successors, we write to you as a matter of urgency about an imminent threat to the future of this global network. The European Commission’s proposal for Article 13 of the proposed Directive for Copyright in the Digital Single Market Directive was well-intended. As creators ourselves, we share the concern that there should be a fair distribution of revenues from the online use of copyright works, that benefits creators, publishers, and platforms alike. But Article 13 is not the right way to achieve this. By requiring Internet platforms to perform automatic filtering all of the content that their users upload, Article 13 takes an unprecedented step towards the transformation of the Internet from an open platform for sharing and innovation, into a tool for the automated surveillance and control of its users. Europe has been served well by the balanced liability model established under the Ecommerce Directive, under which those who upload content to the Internet bear the principal responsibility for its legality, while platforms are responsible to take action to remove such content once its illegality has been brought to their attention. By inverting this liability model and essentially making platforms directly responsible for ensuring the legality of content in the first instance, the business models and investments of platforms large and small will be impacted. The damage that this may do to the free and open Internet as we know it is hard to predict, but in our opinions could be substantial.
    [Show full text]
  • ACM Bytecast​
    ACM Bytecast - Radia Perlman - Episode 3 ​ Transcript Jessica Bell: This is ACM Bytecast, a podcast series from the Association for Computing Machinery, the world's largest educational and scientific computing society. We talk to researchers, practitioners and innovators, who are all at the intersection of computing, research, and practice. They share their experiences, the lessons they've learned, and their own visions for the future of computing. I'm your host, Jessica Bell. Jessica Bell: Today, I have the great pleasure of talking to Radia Perlman, a computer scientist and researcher, who made great strides in the field of networking. You might have heard of STP, or spanning tree protocol. Radio wrote the algorithm which powers this technology. Welcome, Radia. Radia Perlman: Hello, Jessica. Pleased to be here. Jessica Bell: I'm so happy to have you too. I'd like to start with just a little introduction of yourself, and tell us a bit about who you are. Radia Perlman: Well, I work at Dell Technologies. I design network and security things. Jessica Bell: Great. So somebody who came into the computing society fairly recently, I've read a lot about your career. And it seems like you weren't necessarily destined to be a computer scientist. I've even seen some interviews where you self describe as hating computers. I'd love to know a little bit more about how you not only got into this career, but ended up developing some of the pioneering technology that we all use today. Could you walk me through how you got into tech and how you got over "hating computers"? Radia Perlman: Yeah.
    [Show full text]