...WHITE PAPER BIDIRECTIONAL FORWARDING DETECTION FOR OSPF Fast Failure Detection to Speed Network Convergence OVERVIEW In both Enterprise and Service Provider networks, the convergence of business-critical applications onto a common IP infrastructure is becoming more common. Given the criticality of the data, these networks are typically constructed with a high degree of redundancy. While such redundancy is desirable, its effectiveness is dependant upon the ability of individual network devices to quickly detect failures and reroute traffic to an alternate path. This detection is now typically accomplished via hardware detection mechanisms. However, the signals from these mechanisms are not always conveyed directly to the upper protocol layers. When the hardware mechanisms do not exist (eg: Ethernet) or when the signaling does not reach the upper protocol layers, the protocols must rely on their much slower strategies to detect failures. The detection times in existing protocols are typically greater than one second, and sometimes much longer. For some applications, this is too long to be useful. Bi-directional Forwarding Detection (BFD) provides rapid failure detection times between forwarding engines, while maintaining low overhead. It also provides a single, standardized method of link/device/protocol failure detection at any protocol layer and over any media. THE PROBLEM WITH CONVERGENCE The process of network convergence can be broken up into a set of discreet events*:...
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...3 Layer +3 protocols * 4 Layer 3 protocols (Network Layer) * 5 Layer 3.5 protocols * 6 Layer 3+4 protocol suites * 7 Layer 4 protocols (Transport Layer) * 8 Layer 5 protocols (Session Layer) * 9 Other protocols * 10 Layer 7 protocols (Application Layer) * 11 Protocol description languages * 12 See also * 13 Further reading * 14 External links Layer 1 protocols (physical Layer) * Telephone network modems- V.92 * IRDA physical layer * USB physical layer * EIA RS-232, EIA-422, EIA-423, RS-449, RS-485 * Ethernet physical layer Including 10BASE-T, 10BASE2, 10BASE5, 100BASE-TX, 100BASE-FX, 100BASE-T, 1000BASE-T, 1000BASE-SX and other varieties * Varieties of 802.11 Wi-Fi physical layers * DSL * ISDN * T1 and other T-carrier links, and E1 and other E-carrier links * SONET/SDH * Optical Transport Network (OTN) * GSM Um air interface physical layer * Bluetooth physical layer * ITU Recommendations: see ITU-T * IEEE 1394 interface *...
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...Chapter 1 – Chapter 2 – Chapter 3 – 1) What is different about the method used to boost a digital signal’s strength, compared with the method of boosting an analog signal’s strength? • A digital signal requires a repeater, which retransmits the signal in its original form, and an analog signal requires an amplifier, which increases the strength of both the signal and the noise it has accumulated. 2) Which of the following decimal numbers corresponds to the binary number 00001001? • 9 3) A wave with which of the following frequencies would have the longest wavelength? • 10 MHz 4) Ethernet relies on which of the following transmission types? • full-duplex 5) In wavelength division multiplexing, two modulated signals are guaranteed to differ in what characteristic? • Color 6) Which of the following can increase latency on a network? • Adding 50 meters to the length of the network 7) What part of a cable protects it against environmental damage? • Sheath 8) You are helping to install a cable broadband system in your friend’s home. She wants to bring the signal from where the service provider’s cable enters the house to a room on another floor, which means you have to attach a new cable to the existing one. What type of cable should this be? • RG-6 9) With everything else being equal, a network using which of the following UTP types will suffer the most cross talk? • Cat 3 10) Which of the following is not a source of EMI? • Megaphone 11) Which...
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...Question | Answer | What is an example of software that creates packs for moving data across networks? | Internet Protocol | What most often provides the physical connection between the PC and the network? | NIC | What enables a computer to send a packet that every other PC on the network will process? | The Broadcast address | What can you use to connect two very different networks? | A router | Every NIC has a hard-coded identifier called what? | MAC Address | What provides an excellent tool for conceptualizing how a network works? | OSI 7 layer model | On a sending machine, data gets broken up at what layer of the OSI 7 layer model? | Transport layer or layer 4 | NIC's encapsulate data into a _________ for sending that data over a network. | Frame | A ______ enables multiple machines to connect over a network. | Hub | The ________ provides the key interface between the physical and network layers. | Data link layer | Which layer of the osi 7 layer model converts the ones and zeroes to electrical signals and places these signals on the cable? | Physical layer | The term "unshielded twisted pair" is best described by what network component? | Cable | What best describes the contents of a typical network frame? | Recipient's MAC address, sender's MAC address, data, CRC | 23.4F.17.8A.4C.10 is most likely to be what type of address assigned to a NIC? | MAC Address | Which layer of the OSI model involves routing? | Network layer | How much data can...
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...------------------------------------------------- OSI model From Wikipedia, the free encyclopedia OSI model | 7. Application Layer | NNTP · SIP · SSI · DNS · FTP · Gopher · HTTP · NFS · NTP · SMPP · SMTP ·DHCP · SNMP · Telnet · Netconf ·(more) | 6. Presentation Layer | MIME · XDR · TLS · SSL | 5. Session Layer | Named Pipes · NetBIOS · SAP · L2TP ·PPTP | 4. Transport Layer | TCP · UDP · SCTP · DCCP · SPX | 3. Network Layer | IP (IPv4, IPv6) · ICMP · IPsec · IGMP ·IPX · AppleTalk | 2. Data Link Layer | ATM · SDLC · HDLC · ARP · CSLIP ·SLIP · PLIP · IEEE 802.3 · Frame Relay · ITU-T G.hn DLL · PPP · X.25 | 1. Physical Layer | EIA/TIA-232 · EIA/TIA-449 · ITU-T V-Series · I.430 · I.431 · POTS · PDH ·SONET/SDH · PON · OTN · DSL ·IEEE 802.3 · IEEE 802.11 · IEEE 802.15 · IEEE 802.16 · IEEE 1394 · ITU-T G.hn PHY · USB · Bluetooth · Blue | This box: view · talk · edit | The Open Systems Interconnection model (OSI model) is a product of the Open Systems Interconnection effort at the International Organization for Standardization. It is a way of sub-dividing a communications system into smaller parts called layers. A layer is a collection of similar functions that provide services to the layer above it and receives services from the layer below it. On each layer, an instance provides services to the instances at the layer above and requests service from the layer below. For example, a layer that provides error-free communications across...
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...TELECOMMUNICATION SWITCHING AND NETWORKS TElECOMMUNICATION SWITCHING NffiWRKS AND THIS PAGE IS BLANK Copyright © 2006, 2005 New Age International (P) Ltd., Publishers Published by New Age International (P) Ltd., Publishers All rights reserved. No part of this ebook may be reproduced in any form, by photostat, microfilm, xerography, or any other means, or incorporated into any information retrieval system, electronic or mechanical, without the written permission of the publisher. All inquiries should be emailed to rights@newagepublishers.com ISBN (10) : 81-224-2349-3 ISBN (13) : 978-81-224-2349-5 PUBLISHING FOR ONE WORLD NEW AGE INTERNATIONAL (P) LIMITED, PUBLISHERS 4835/24, Ansari Road, Daryaganj, New Delhi - 110002 Visit us at www.newagepublishers.com PREFACE This text, ‘Telecommunication Switching and Networks’ is intended to serve as a onesemester text for undergraduate course of Information Technology, Electronics and Communication Engineering, and Telecommunication Engineering. This book provides in depth knowledge on telecommunication switching and good background for advanced studies in communication networks. The entire subject is dealt with conceptual treatment and the analytical or mathematical approach is made only to some extent. For best understanding, more diagrams (202) and tables (35) are introduced wherever necessary in each chapter. The telecommunication switching is the fast growing field and enormous research and development are undertaken by...
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...A digital signal is a physical signal that is a representation of a sequence of discrete values (a quantified discrete-time signal), for example of an arbitrary bit stream, or of a digitized (sampled and analog-to-digital converted) analog signal. The term digital signal can refer to either of the following: any continuous-time waveform signal used in digital communication, representing a bit stream or other sequence of discrete values a pulse train signal that switches between a discrete number of voltage levels or levels of light intensity, also known as a line coded signal or baseband transmission, for example a signal found in digital electronics or in serial communications, or a pulse code modulation (PCM) representation of a digitized analog signal. A signal that is generated by means of a digital modulation method (digital passband transmission), to be transferred between modems, is in the first case considered as a digital signal, and in the second case as converted to an analog signal. ======================== An analog or analogue signal is any continuous signal for which the time varying feature (variable) of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. For example, in an analog audio signal, the instantaneous voltage of the signal varies continuously with the pressure of the sound waves. It differs from a digital signal, in which a continuous quantity is represented by a discrete function which...
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...Don't forget to check out the Online Learning Center, www.mhhe.com/forouzan for additional resources! Instructors and students using Data Communications and Networking, Fourth Edition by Behrouz A. Forouzan will find a wide variety of resources available at the Online Learning Center, www.mhhe.comlforouzan Instructor Resources Instructors can access the following resources by contacting their McGraw-Hill Representative for a secure password. PowerPoint Slides. Contain figures, tables, highlighted points, and brief descriptions of each section. Complete Solutions Manual. Password-protected solutions to all end-of-chapter problems are provided. a Pageout. A free tool that helps you create your own course website. D Instructor Message Board. Allows you to share ideas with other instructors using the text. a o Student Resources The student resources are available to those students using the book. Once you have accessed the Online Learning Center, click on "Student Resources," then select a chapter from the drop down menu that appears. Each chapter has a wealth of materials to help you review communications and networking concepts. Included are: Chapter Summaries. Bulleted summary points provide an essential review of major ideas and concepts covered in each chapter. a Student Solutions Manual. Contains answers for odd-numbered problems. Glossary. Defines key terms presented in the book. Flashcards. Facilitate learning through practice and review. a Animated Figures...
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...ACKNOWLEDEMENT We thank most of all God Almighty for his mercies and grace that kept us all through our seminar research and for giving us wisdom that was implemented in course of the research work. We are greatly indebted to our supervisor, ENGR. JOHN CHUKWU for his love, courage, guidance and investment to the group, who sacrificed his time and schedule just to make sure that the best is been brought out from this group and also to the group leader who consistently made every effort and spent sleepless night ensuring that the seminar topic research was a worthwhile and fulfilling one, also to us been the group members who contributed to the success of the research topic. We also want to thank the head of engineering department(HOD) who also contributed in his own way and also to school for bringing out the seminar format which guided us well and made our work easier. And to our most beloved parents, guardians which God used in providing the financial resources for us. We say a very big thank you to them all and pray that God bless us all. THANKS CHAPTER ONE INTRODUCTION DEFINITIONS OF SOME TERMS A DIGITAL SYSTEM is a data technology that uses discrete (discontinuous) values. By contrast, non-digital (or analog) systems represent information using a continuous function. Although digital representations are discrete, the information represented can be either discrete, such as numbers and letters or continuous, such as sounds, images, and other measurements...
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...WEST VISAYAS STATE UNIVERSITY INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY La Paz, Iloilo City A Digital Scrapbook in Basic Networking Submitted to: ARNEL N. SECONDES Subject Instructor Submitted by: Frenze Chloe Baluco Janice Gayapa Christian John Elnacin BSIT 2A October 3, 2014 TABLE OF CONTENTS Title Page Table of Contents Introduction Networking Fundamentals Networking Lexicon Network Types Network Design Standard Topologies Hubs Switches Variation of Major Topologies Network Media Network Cabling: Tangible Physical Media Primary Cable Types Wireless Networking: Intangible Media Types of Wireless Network Network Interface Card Network Interface Card (NIC) Basics Special-Purpose NIC’s References ------------------------------------------------- Networking Fundamentals Networking History and Evolution The earliest form of electronic networking for the purpose of message transfer was the local telephone exchange, which has evolved to become a carrier network providing transport services for both voice and data traffic on a global scale. Data networks designed exclusively for computing environments followed the introduction of business computing in the 1950s. Prior to that time, computers were used mostly for research and national defense purposes. Milestones in the history of data networking include: * 1960s—The first large-scale commercial computer network is created for an airline reservation application...
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...BSR 64000 Command Reference Guide Compass ID: 271820115 Version 3 Release 5.0.0 Notice Copyright © 2008 Motorola, Inc. All rights reserved No part of this publication my be reproduced in any form or by any means or used to make any derivative work (such as translation, transformation or adaptation) without written permission from Motorola, Inc. Motorola reserves the right to revise this publication and to make changes in content from time to time without obligation on the part of Motorola to provide notification of such revision or change. Motorola provides this guide without warranty of any kind, either implied or expressed, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Motorola may make improvements or changes in the product(s) described in this manual at any time. Motorola and the stylized M logo are registered trademarks of Motorola, Inc. Broadband Services Router, BSR, BSR 64000, RiverDelta, and SmartFlow are trademarks of Motorola, Inc. All other trademarks and registered trademarks are the property of their respective owners. Caring for the Environment by Recycling When you see this symbol on a Motorola product, do not dispose of the product with residential or commercial waste. Recycling your Motorola Equipment Please do not dispose of this product with your residential or commercial waste. Some countries or regions, such as the European Union, have set up systems to collect and recycle electrical...
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...1.Комуникациски систем 11. Општиот модел на комуникациски систем се состои од ���� * Извор ���� * Предавател ���� * Систем за пренос ���� * Одредиште ���� * Медиум за пренос 12. Кои се основни задачи на еден комуникациски систем ���� * Синхронизација � ���* Адресирање 13. Кои од следните искази се точни за компјутерските мрежи ���� * Компјутерска мрежа е колекција од меѓусебно поврзани компјутери ������ Основен модел на компјутерска мрежа е клиент-клиент моделот ������ Денес компјутерските мрежи повеќе се применуваат заради поделба на информации и ресурси меѓу компјутерите ���� * Денес компјутерските мрежи повеќе се применуваат заради поделба на информации и ресурси меѓу луѓето ������ Основна поделба на комуникациски мрежи е на SAN и MAN 14. Кои од следните се популарни облици на е-трговија ���� * B2B ���� * C2C ���� * P2P ������ G2B ������ B2G 15. Кои од следниве искази не се точни за широко распространетите мрежи (WAN) ������ Покриваат голема географска област ���� * Јазлите во мрежата зависат од содржината на податокот кој го пренесуваат ���� * Најголема WAN е Интранет ������ Главна цел е да овозможи доверлив, брз и сигурен пренос на податоци ���� * Најчест пример на WAN која е иплементирана со преклопување на кола е комуникацијата терминал � компјутер 16. Брзината на пренос на податоци кај WAN e од ���� * 64Kbps кај WAN со пакетен пренос ���� * 2Мbps кај WAN со пренос на рамки ���� * 10Мbps кај WAN со асинхрон пренос ������ 64Kbps кај WAN со пренос на рамки ������ 2Мbps...
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...THEORY The correct answer(s): D What is the default IPX Ethernet encapsulation? A.) SNAP B.) Arpa C.) 802.2 D.) Novell-Ether E.) SAP Novell-ether is the default LAN encapsulation. Novell-ether is 802.3. The correct answer(s): A What must be true for two Routers running IGRP to communicate their routes? A.) Same autonomous system number B.) Connected using Ethernet only C.) Use composite metric D.) Configured for PPP For two routers to exchange IGRP routes they must be configured with the same autonomous system number. The correct answer(s): C The following is partial output from a routing table, identify the 2 numbers in the square brackets; '192.168.10.0 [100/1300] via 10.1.0.1, 00:00:23, Ethernet1' A.) 100 = metric, 1300 = administrative distance B.) 100 = administrative distance, 1300 = hop count C.) 100 = administrative distance, 1300 = metric D.) 100 = hop count, 1300 = metric The first number is the Administrative distance and the seconds number is the metric. In this case it is an IGRP metric. The correct answer(s): A B C Identify 3 methods used to prevent routing loops? A.) Split horizon B.) Holddown timers C.) Poison reverse D.) SPF algorithm E.) LSP's Routing loops can be prevented by split horizon, poison reverse and holddown times. The other two choices relate to Link State. The correct answer(s): A Which statement is true regarding full duplex? A.) Allows for transmission and receiving...
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...INFORMATION RESOURCE GUIDE Computer, Internet and Network Systems Security An Introduction to Security i Security Manual Compiled By: S.K.PARMAR, Cst N.Cowichan Duncan RCMP Det 6060 Canada Ave., Duncan, BC 250-748-5522 sunny@seaside.net This publication is for informational purposes only. In no way should this publication by interpreted as offering legal or accounting advice. If legal or other professional advice is needed it is encouraged that you seek it from the appropriate source. All product & company names mentioned in this manual are the [registered] trademarks of their respective owners. The mention of a product or company does not in itself constitute an endorsement. The articles, documents, publications, presentations, and white papers referenced and used to compile this manual are copyright protected by the original authors. Please give credit where it is due and obtain permission to use these. All material contained has been used with permission from the original author(s) or representing agent/organization. ii T eofContent abl 1.0 INTRODUCTION........................................................................................................................................................... 2 1.1 BASIC INTERNET TECHNICAL DETAILS ........................................................................................................................ 2 1.1.1 TCP/IP : Transmission Control Protocol/Internet Protocol .........................................
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...Emory University | Internetworking Technology Handbook | [Type the document subtitle] | | SAVIOUR EMMANUEL UDOBONG | [Pick the date] | [Type the abstract of the document here. The abstract is typically a short summary of the contents of the document. Type the abstract of the document here. The abstract is typically a short summary of the contents of the document.] | Internetworking Basics An internetwork is a collection of individual networks, connected by intermediate networking devices, that functions as a single large network. Internetworking refers to the industry, products, and procedures that meet the challenge of creating and administering internetworks. The following articles provide information about internetworking basics: * Internetworking Basics * Introduction to LAN Protocols * Introduction to WAN Technologies * Bridging and Switching Basics * Routing Basics * Network Management Basics * Open System Interconnection Protocols LAN Technologies A LAN is a high-speed data network that covers a relatively small geographic area. It typically connects workstations, personal computers, printers, servers, and other devices. LANs offer computer users many advantages, including shared access to devices and applications, file exchange between connected users, and communication between users via electronic mail and other applications. The following articles provide information different LAN technologies: * Ethernet...
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