For information on all Morgan Kaufmann publications, visit our Web site at or

Size: px
Start display at page:

Download "For information on all Morgan Kaufmann publications, visit our Web site at www.mkp.com or www.elsevierdirect.com"

Transcription

1

2 Morga Kaufma Publishers is a imprit of Elsevier. 30 Corporate Drive, Suite 400, Burligto, MA 01803, USA This book is prited o acid-free paper. # 2009 by Elsevier Ic. All rights reserved. Desigatios used by compaies to distiguish their products are ofte claimed as trademarks or registered trademarks. I all istaces i which Morga Kaufma Publishers is aware of a claim, the product ames appear i iitial capital or all capital letters. All trademarks that appear or are otherwise referred to i this work belog to their respective owers. Neither Morga Kaufma Publishers or the authors ad other cotributors of this work have ay relatioship or affiliatio with such trademark owers or do such trademark owers cofirm, edorse or approve the cotets of this work. Readers, however, should cotact the appropriate compaies for more iformatio regardig trademarks ad ay related registratios. No part of this publicatio may be reproduced, stored i a retrieval system, or trasmitted i ay form or by ay meas electroic, mechaical, photocopyig, scaig, or otherwise without prior writte permissio of the publisher. Permissios may be sought directly from Elsevier s Sciece & Techology Rights Departmet i Oxford, UK: phoe: (þ44) , fax: (þ44) , You may also complete your request olie via the Elsevier homepage (http://elsevier.com), by selectig Support & Cotact the Copyright ad Permissio ad the Obtaiig Permissios. Library of Cogress Catalogig-i-Publicatio Data Applicatio Submitted ISBN: For iformatio o all Morga Kaufma publicatios, visit our Web site at or Prited i the Uited States of America

3 To my wife Gia ad our daughter Jacquelie JFB To my lovely daughters Agie ad Kiki HY To our adorable so Athoy EKL

4 Preface Ratioale Peer-to-peer etworkig has emerged as a viable busiess model ad systems architecture for Iteret-scale applicatios. Although its techological roots trace back through several decades of desigig distributed iformatio systems, cotemporary applicatios demostrate that it is a effective way to build applicatios that coect millios of users across the globe without reliace o specially deployed servers. Istead, by combiig the resources of each user s computer, these systems automatically self-orgaize ad adapt to chagig peer populatios while providig services for cotet sharig ad persoal commuicatios. Public attetio to peer-to-peer applicatios came first from highly popular file-sharig systems, i which decetralizatio was used to support a busiess model that eeded to legitimize licesed cotet sharig. The subsequet success of the Skype Iteret telephoy applicatio showed the geerality of the peer-to-peer approach ad its feasibility to provide acceptable service quality to millios of users. Subsequetly there has bee growig iterest i improvig o these systems as well as cosiderig ew desigs to attai better performace, security, ad flexibility. Today it is aticipated that peer-to-peer techologies will become geeral-purpose, widely used vehicles for buildig a broad rage of applicatios for social etworkig, iformatio delivery, ad persoal commuicatios applicatios i the future. There are may importat questios about the evolutio of peer-to-peer techologies. What ew applicatios will drive this evolutio? Will P2P be used as a geeral-purpose techique for buildig ay distributed applicatio? How do treds i wireless etworkig, cosumer electroics, home etworkig, high-defiitio cotet, digital rights maagemet, ad so forth itersect with peer-to-peer? Is P2P a paacea for desigig large-scale applicatios, or if ot, what are the characteristics of applicatios for which it is well suited? How should other architectures coexist with ad adapt to peer-to-peer desig? Will the P2P ladscape be Balkaized by may icompatible peer-to-peer protocols ad systems? The topics covered i this book provide a comprehesive survey of both the practice of P2P ad mai research directios ad are iteded to frame the aswers for these questios. Orgaizatio ad Approach The first two chapters itroduce the mai cocepts of peer-to-peer systems. We examie the operatio of a basic P2P system, icludig behavior for self-orgaizig, routig, ad searchig. We also describe a umber of represetative commercial applicatios. The ext four chapters describe the fudametal peer-to-peer overlay architectures, icludig both ustructured ad structured overlays. xvii

5 xviii Preface The last chapter i this group covers importat implemetatio issues such as protocol desig, NAT traversal, ad peer capability assessmet. Detailed discussio of P2P mechaisms to support key applicatios follow, icludig chapters o search, cotet delivery, peercastig ad overlay multicastig, ad overlay-based Iteret telephoy. Importat uses of peer-to-peer overlays that we describe here iclude differet techiques for cotet search, delivery of real-time streamig cotet, ad sessio iitiatio usig the overlay. We the discuss i separate chapters how requiremets for overlay performace, peer mobility, security, ad maagemet itersect with the P2P overlay desig. Throughout the book, to motivate ad illustrate the material, we iclude examples of systems i use ad describe importat research prototypes. We also refer to ope-source implemetatios for readers who seek a hads-o illustratio of the ideas. I particular we use examples from OverlayWeaver, a ope-source toolkit developed by Kazuyuki Shudo that supports a umber of importat peerto-peer algorithms. Access to the ope-source tools ad updates to the book ca be obtaied via the compaio Website at Audiece This book is iteded for professioals, researchers, ad computer sciece ad egieerig studets at the advaced udergraduate level ad higher who are familiar with etworkig ad etwork protocol cocepts ad basic ideas about algorithms. For the more advaced parts of the book, the reader should have geeral familiarity with Iteret protocols such as TCP ad IP routig but should ot eed to kow the details of etwork routig protocols such as BGP or OSPF. For some sectios of the book such as discussios of mobility or multicastig, familiarity with mobility i IP ad IP multicastig will be helpful but ot required. The reader will also fid it helpful to be familiar with otatio for comparig algorithm performace, such as O() or O(log ). For istructors who wat to use the book as a textbook i a class o peer-topeer etworkig, a set of exercises for each chapter, with a aswer key for selected exercises are available by registerig at Peer-to-peer etworkig is geerally see as a ew techology with a disruptive busiess model ad may possibilities for further iovatio. These treds make the subject matter i this book highly relevat to the techology commuity. We hope the book is a valuable startig poit for readers who are ew to the subject ad a importat referece to those who are active i the field. Throughout the book we coclude each chapter with suggestios for further readig for readers who would like to dig deeper ito specific topics. Ackowledgemets Durig the preparatio of this book, may people provided help i reviewig portios of the text ad the origial book proposal. We greatly appreciate their suggestios ad efforts i improvig the quality of the book.

6 Preface xix First, we would like to thak those idividuals who reviewed the origial proposal ad made importat commets about structure, topics, ad emphasis: Germao Caroi, Google; Christos Gkatsidis, Microsoft Research; Wolfgag Kellerer, DOCOMO Euro-Labs; Xuemi (Sherma) She, Uiversity of Waterloo; ad Xiaotao Wu, Avaya Labs Research. I additio, Wolfgag Kellerer, DOCOMO Euro-Labs, reviewed a substatial portio of the book ad provided may useful suggestios. We are also grateful to those who reviewed ad commeted o portios of the book: Yi Cui, Vaderbilt Uiversity; Awitama Datta, Nayag Techological Uiversity; Aaro Harwood, Uiversity of Melboure; Vaa Kalogeraki, Uiversity of Califoria Riverside; Mario Kolberg, Uiversity of Stirlig; Be Leog, Natioal Uiversity of Sigapore; Li Li, Commuicatios Research Cetre Caada; Ludy Lewis, Souther New Hampshire Uiversity; Muthucumaru Maheswara, McGill Uiversity; Kurt Tutschku, Uiversity of Viea; Megku Yag, Easter Ketucky Uiversity; Weju (Kevi) Zeg, Uiversity of Missouri-Columbia. The efforts ad costructive commets of all the reviewers are greatly appreciated. Ay mistakes that remai are the resposibility of the authors. Thaks are due to the staff at Morga Kaufma--Rick Adams, Seior Acquisitios Editor; assistat editors Gregory Chalso, Maria Aloso, ad Lidsey Gedall; ad our project maager, Melida Ritchie. Fially we thak our families for their support ad uderstadig while we worked o this book. Joh F. Buford, Priceto, NJ Heather Yu, Priceto, NJ Eg Keog Lua, Japa ad USA

7 About the Authors Joh F. Buford is Research Scietist, Avaya Labs Research, Baskig Ridge, NJ. Previously he was Lead Scietist at Paasoic Techologies, VP of Software Developmet at Kada Systems, Director of Iteret Techologies at Verizo, ad Assoc. Prof. of Computer Sciece at Uiversity of Massachusetts Lowell. PhD i Computer Sciece, Graz Uiversity of Techology. Heather Yu is Seior Maager of Media Techologies at Huawei Techologies USA, Bridgewater, NJ where she leads the research o multimedia cotet etworkig ad digital media techologies. PhD i Electrical Egieerig, Priceto Uiversity. Eg Keog Lua is Faculty Member of College of Egieerig, Iformatio Networkig Istitute at Caregie Mello Uiversity, Pittsburgh, USA, ad Systems Scietist, Caregie Mello CyLab USA ad Japa. Previously he held research fellowship ad idustry cosultig positios at the NTT Laboratories, Itel Research, Microsoft Research, ad Hewlett-Packard R&D/Cosultig. His research areas iclude Peer-to-Peer etworks, Iteret-scale P2P overlay multimedia commuicatios, etwork security ad future Iteret. PhD i Computer Sciece, Uiversity of Cambridge, UK. xxi

8 CHAPTER Itroductio 1 Our discussio of peer-to-peer (P2P) cocepts starts with a overview of the key applicatios ad their emergece as maistream services for millios of users. The chapter the examies the relatioship of P2P with the Iteret ad its distictive features compared to other service architectures. A review of P2P ecoomics, busiess models, social impact, ad related techology treds cocludes the chapter. P2P EMERGES AS A MAINSTREAM APPLICATION The Rise of P2P File-Sharig Applicatios Nearly 10 years after the World Wide Web became available for use o the Iteret, decetralized peer-to-peer file-sharig applicatios supplated the serverbased Napster applicatio, which had popularized the cocept of file sharig. Napster s cetralized directories were its Achilles heel because, as it was argued i court, Napster had the meas, through its servers, to detect ad prevet registratio of copyrighted cotet i its service, but it failed to do so. Napster was subsequetly foud liable for copyright ifrigemet, dealig a lethal blow to its busiess model. As Napster was cosumed i legal challeges, secod-geeratio protocols such as Gutella, FastTrack, ad BitTorret adopted a peer-to-peer architecture i which there is o cetral directory ad all file searches ad trasfers are distributed amog the correspodig peers. Other systems such as FreeNet also icorporated mechaisms for cliet aoymity, icludig routig requests idirectly through other cliets ad ecryptig messages betwee peers. Meawhile, the top labels i the music idustry, which have had arguably the most serious reveue loss due to the emergece of file sharig, have cotiued to pursue legal challeges to these systems ad their users. Regardless of the outcome of these court cases, the social perceptio of the acceptability ad beefits of cotet distributio through P2P applicatios has 1

9 2 CHAPTER 1 Itroductio bee irrevocably altered. I the music idustry prior to P2P file sharig, audio CDs were the domiat distributio mechaism. Web portals for olie music were limited i terms of the size of their catalogs, ad dowloads were expesive. Although P2P file sharig became widely equated with cotet piracy, it also showed that cosumers were ready to replace the CD distributio model with a olie experiece if it could provide a large portfolio of titles ad artists ad if it icluded features such as a search, previews, trasfer to CD ad persoal music players, ad idividual track purchase. As portals such as itues emerged with these properties, a tremedous growth i the olie music busiess resulted. I a typical P2P file-sharig applicatio, a user has digital media files he or she wats to share with others. These files are registered by the user usig the local applicatio accordig to properties such as title, artist, date, ad format. Later, other users aywhere o the Iteret ca search for these media files by providig a query i terms of some combiatio of the same attributes. As we discuss i detail i later chapters, the query is set to other olie peers i the etwork. A peer that has local media files matchig the query will retur iformatio o how to retrieve the files. It may also forward the query to other peers. Users may receive multiple successful resposes to their query ad ca the select the files they wat to retrieve. The files are the dowloaded from the remote peer to the local machie. Examples of file-sharig cliet user iterfaces are show i Figures 1.1 ad 1.2. FIGURE 1.1 LimeWire cliet.

10 P2P Emerges as a Maistream Applicatio 3 FIGURE 1.2 emule cliet search iterface. Despite their popularity, P2P file-sharig systems have bee plagued by several problems for users. First, some of the providers of leadig P2P applicatios ear reveue from third parties by embeddig spyware ad malware ito the applicatios. Users the fid their computers ifected with such software immediately after istallig the P2P applicatio. Secod, a large amout of polluted or corrupted cotet has bee published i file-sharig systems, ad it is difficult for a user to distiguish such cotet from the origial digital cotet they seek. It is geerally felt that pollutio attacks o file-sharig systems are iteded to discourage the distributio of copyrighted material. A user dowloadig a polluted music file might fid, for example, oise, gaps, ad abbreviated cotet. A third type of problem affectig the usability of P2P file-sharig applicatios is the free-rider problem. A free rider is a peer that uses the file-sharig applicatio to access cotet from others but does ot cotribute cotet to the same degree to the commuity of peers. Various techiques for addressig the freerider problem by offerig icetives or moitorig use are discussed later i the book. A related issue is that of peer chur. A peer s cotet ca oly be accessed by other peers if that peer is olie. Whe a peer goes offlie, it takes time for other peers to be alerted to the chage i status. Meawhile, cotet queries may go uaswered ad time out.

11 4 CHAPTER 1 Itroductio The leadig P2P file-sharig systems have ot adopted mechaisms to protect licesed cotet or collect paymet for trasfers o behalf of copyright owers. Several vetures seek to legitimize P2P file sharig for licesed cotet by icorporatig techiques for digital rights maagemet (DRM) ad superdistributio ito P2P distributio architectures. I such systems, cotet is ecrypted, ad though it ca be freely distributed, a user must separately purchase a ecrypted licese file to reder the media. Through the use of digital sigatures, such licese files are ot easily trasferred to other users. See this book s Website for liks to curret P2P file-sharig proposals for DRM-based approaches. Other vetures such as QTrax, SpiralFrog, ad TurItUp are proposig a adbased model for free music distributio. The user ca freely dowload the music file, which i some models is protected with DRM, but must liste to or watch a ad durig dowload or playback. I these schemes, the advertiser istead of the user is payig the cotet licesig costs. Questios remai about this model, such as whether it will udercut existig music dowload busiess models ad whether the advertisig reveue is sufficiet to match the licesig reveue from existig music dowload sites. Voice over P2P (VoP2P) Desktop VoIP (voice over IP) cliets bega to appear i the mid-1990s ad offered free desktop-to-desktop voice ad video calls. These applicatios, though ecoomically attractive ad techically iovative, did t attract a large followig due to factors such as lack of voice quality ad limited availability of broadbad access i the cosumer market. I additio, the iitially small size of the etwork commuity limited the potetial of such applicatios to supplat covetioal telephoy. This cotiues to be a practical issue facig ew types of P2P applicatios how to create a commuity of users that ca reach the critical mass eeded to provide the value propositio that comes with scale. Startig i 1996 with the lauch of ICQ, a umber of istat-message ad presece (IMP) applicatios became widely popular. The leadig IMP systems, such as AIM, Microsoft Messeger, Yahoo! Messeger, ad Jabber, all use cliet/server architectures. 6 Although several of these systems have subsequetly icluded telephoy capabilities, their telephoy features have ot draw a large user commuity. Skype is a VoP2P cliet lauched i 2003 that has reached more tha 10 millio cocurret users. The VoP2P techology of Skype is discussed i Chapter 11. Compared to earlier VoIP cliets, Skype offers both free desktop-to-desktop calls ad low-cost desktop-to-public switched telephoe etwork (PSTN) calls, icludig iteratioal calls. The call quality is high, geerally attributed to the audio codec Skype uses ad today s wide use of broadbad access etworks to reach the Iteret. I additio, Skype icludes features from IMP applicatios, icludig buddy lists, istat messagig, ad presece. Ulike the file-sharig systems, Skype promises a o spyware policy.

12 P2P Emerges as a Maistream Applicatio 5 FIGURE 1.3 Skype cliet. The Skype user iterface is show i Figure 1.3. It icludes a buddy list that shows other buddies ad their olie status. The user ca select buddies to iitiate free chat, voice, ad group coferece sessios. The user ca also eter PSTN umbers to call, ad these calls are charged. P2PTV The success of P2P file sharig ad VoP2P motivated use of P2P for streamig video applicatios. P2PTV delivery ofte follows a chael orgaizatio i which cotet is orgaized ad accessed accordig to a directory of programs ad movies. Ulike file-sharig systems i which a media file is first dowloaded to the user s computer ad the played locally, video-streamig applicatios must provide a real-time stream trasfer rate to each peer that equals the video playback rate. Thus if a media stream is ecoded at 1.5 Mbps ad there is a siglepeeractigasthesourceforthestream,thepathfromthesourcepeerto the playback peer must provide a data trasfer rate of 1.5 Mbps o average. Somevariatioitheplaybackratealog the path ca be accommodated by prebufferig a sufficiet umber of video frames. The if the trasfer rate temporarily drops, the extra cotet i the buffer is used to prevet dropouts at the rederig side.

13 6 CHAPTER 1 Itroductio A attractive feature of peer-to-peer architectures for delivery of video streams is their self-scalig property. Each additioal peer added to the P2P system adds additioal capacity to the overall resources. Eve powerful server farms are limited to the maximum umber of simultaeous video streams that they ca deliver. I a P2P etwork, ay peer receivig a video stream ca also forward it to a few other peers. If D > 1 peers are directly coected to the source peer ad each peer ca i tur support D peers, the up to D 2 þ D peers ca receive a video stream withi two hops from the source. Likewise, if each of the secod-tier D peers ca i tur support D peers, up to D 3 þ D 2 þ D peers ca receive the video stream i three hops. Note that each hop adds a small forwardig delay, which is usually ot a problem i oe-way video-streamig applicatios. This simple model is good if all peers watchig the specific video stream are viewig the same positio i the stream close to simultaeously, equivalet to a broadcast televisio chael. However, i video-o-demad type applicatios, peers start viewig a stream at arbitrary times, ad those peers that start viewig a stream cocurretly may soo diverge i stream positio due to user actios such as pause or rewid. To avoid trasferrig complete copies of video files to peers at playback, a method is eeded for a peer to locate the ext chuk of video i its playback schedule from some other peers i the P2P system. Oe techique used i BitTorret 243 is for the source of the cotet to seed other peers with chuks of the cotet. These peers the access the torret created by the source to idetify each other ad retrieve the cotet chuks directly from other peers. Such a group of peers exchagig chuks is called a swarm. As is the case with other P2P applicatios, the volatility of peers could cause gaps i stream playback if the peer that is the source of the ext segmet of video suddely leaves the P2P system. Sice peers are user-cotrolled ed systems, upredictable ad uaouced departures are a assumed hazard. Most P2P etworks have specific protocols to recogize such departures ad to cotiually locate ew peers that are joiig the P2P system. For video-streamig applicatios, mitigatig the departure of a source peer ca ivolve periodically searchig for redudat sources (which are also volatile) ad providig a sufficiet buffer to reduce the impact o the user s viewig experiece whe a source peer departure does occur. Outside of P2P video applicatios, a great deal of research has dealt with the issues of reliable etwork delivery of real-time video. Due to etwork cogestio ad etwork failures, packets may sometimes get dropped. P2P etworks deped o the uderlyig physical etwork. Cosequetly, techiques already developed for reliable delivery of streams i packet etworks are applicable i P2P overlay etworks. Such techiques iclude adaptive video delivery, multiresolutio video, ad scalable video ad are discussed i Chapter 8. Several P2PTV applicatios are available. Examples iclude Babelgum, Joost, PPLive, PPStream, SopCast, TVats, TVUPlayer, Veoh TV, ad Zattoo (see Figure 1.4).

14 P2P Emerges as a Maistream Applicatio 7 FIGURE 1.4 P2PTV applicatios, (A) Bablegum # 2008 Bablegum. Reprited by permissio, (B) Zattoo # 2007 Zattoo. Reprited by permissio, (C) TVU Networks # 2008 TVU Networks. Reprited by permissio.

15 8 CHAPTER 1 Itroductio P2P NETWORKING AND THE INTERNET P2P Overlays ad Network Services Peers i P2P applicatios commuicate with other peers usig messages trasmitted over the Iteret or other types of etworks. The protocol for a P2P applicatio is the set of differet message types ad their sematics, which are uderstood by all peers. The protocols of various P2P applicatios have some commo features. First, these protocols are costructed at the applicatio layer of the etwork protocol stack. Secod, i most desigs peers have a uique idetifier, which is the peer ID or peer address. Third, may of the message types defied i various P2P protocols are similar. Fially, the protocol supports some type of message-routig capability. That is, a message iteded for oe peer ca be trasmitted via itermediate peers to reach the destiatio peer. To distiguish the operatio of the P2P protocol at the applicatio layer from the behavior of the uderlyig physical etwork, the collectio of peer coectios i a P2P etwork is called a P2P overlay. Figure 1.5 shows the correspodece betwee peers coectig i a overlay etwork with the correspodig hosts, devices, ad routers i the uderlyig physical etwork. Later i this book we discuss importat properties ad details of P2P overlays. For cosistecy, whe we wat to talk about a system of peers usig a commo P2P applicatio layer protocol, we will refer to it as a P2P overlay or simply a overlay. It might be coveiet to thik of a P2P system or P2P etwork as syoyms for P2P overlay. The practice of overlay etworks predates the P2P applicatio era. For example, protocols used i Iteret ews servers ad Iteret mail servers are early examples of widely used overlays that implemet importat etwork services. These specialized overlay etworks were developed for various reasos, such as eablig ed-to-ed etwork commuicatio regardless of etwork boudaries caused by etwork address traslatio (NAT). Aother importat reaso for the use of overlays is to provide a etwork service that is ot yet available withi the etwork. For example, multicast routig is a etwork service that to date has bee oly partially adopted o the Iteret. Multicast routig eables a message set to a sigle multicast address to be routed to all receivers that are members of the multicast group. This is importat for reducig etwork traffic for oe-to-may applicatios such as video broadcastig or videocoferecig. Sice multicast routig is ot uiversally supported i Iteret routers, researchers developed a applicatio layer capability for multicast routig called applicatio layer multicast (ALM) or overlay multicast (OM). These techiques, discussed i Chapter 9, use a type of overlay etwork to provide the multicast service for applicatios. Aother aspect of Iteret routig is that some messages are ot routed via the shortest path. This is due to the ecoomics of the etwork providers that collectively provide the backboe of the Iteret. These etwork providers establish etwork regios that coect at peerig poits to other etwork providers. The

16 P2P Networkig ad the Iteret 9 Peer Super Peer FIGURE 1.5 Peers form a overlay etwork (top) that i tur uses etwork coectios i the ative etwork (bottom). The overlay orgaizatio is a logical view that might ot directly mirror the physical etwork topology. traffic load at a peerig poit may be asymmetric. To maximize the value of the etwork to its customers, a etwork provider may route traffic comig ito its peerig poit differetly depedig o the source of the packet. Cosequetly, differet hosts sedig messages to the same destiatio could see sigificatly differet delays. Resiliet overlay etworks (RONs) are a type of overlay etwork that seeks to provide the shortest path i the physical etwork for a message. Such overlays are discussed i Chapter 11. Fially, other examples of etwork services that ca be supported usig a overlay iclude secure delivery of packets, trust establishmet betwee arbitrary edpoits, aoymous message delivery, ad cesorship-resistat commuicatios. Such services are icompletely provided i today s Iteret ad ca be

17 CHAPTER 1 Itroductio more rapidly delivered usig a overlay etwork because applicatio layer features do ot require etwork hardware upgrades. Impact of P2P Traffic o the Iteret The growig popularity of P2P applicatios has created additioal cotroversy due to its impact o etwork performace. Although traffic measuremets of the global Iteret are difficult to collect ad evaluate, data such as that show i Figure 1.6 idicate that a sigificat ad growig proportio of etwork traffic is due to the popularity of P2P applicatios. More recet measuremets 10 i large U.S. Iteret service providers (ISPs) show that P2P traffic cotiues to be aroud 50% of Iteret traffic i access etworks. This situatio is expected to cotiue as P2P applicatios grow i popularity ad are used to deliver more ad more video files to ed systems. From the perspective of the ISP, a relatively small proportio of etwork users ca overwhelm the capacity of the etwork. Sice ed users i may ISPs are charged either a flat rate or for coect time ad ot bit usage rate, the cost of such usage is bore by all the ISP s customers. A secod issue is that the broadbad access etworks were ot desiged for P2P traffic. P2P traffic is iheretly symmetric because each peer acts as both a cliet ad a server i the P2P overlay. But the widely available broadbad access etworks such as Digital Subscriber Loop (DSL) ad cable modems are asymmetric, with dowstream badwidth capacity beig at least five times that of Percetage of Iteret Traffic P2P FTP Web FIGURE 1.6 Relative percetage of Iteret traffic by applicatio category through (# 2006 Velocix, Reprited by permissio).

18 Motivatio for P2P Applicatios 11 upstream capacity. Thus the etworks of broadbad ISPs are beig overloaded by large volumes of upstream traffic produced by P2P applicatios. The outcome of these coflicts betwee P2P applicatios ad etwork providers depeds i part o the cotiued popularity of P2P applicatios, particularly for media delivery versus the emergece of other distributio models that provide the same cost/beefit. A discussio of curret approaches to ISP maagemet of overlay traffic is foud i Chapter 15. MOTIVATION FOR P2P APPLICATIONS P2P from the Ed User s Perspective Though P2P applicatios have trasformed the typical user s experiece of gettig cotet ad commuicatio services from the Iteret, at the same time other popular Iteret applicatios have ot bee built with P2P techology. Examples iclude social etworkig sites such as MySpace ad cotet-sharig sites such as YouTube. Both P2P applicatios ad these Web-based applicatios provide free services to large umbers of ed users. But the owers of the Web-based applicatios geerate reveue usig ilie advertisemets. These Websites ca measure ad viewership ad click-throughs. Depedig o the applicatio, the Websites ca also relate these statistics to user iformatio that the Website gathers. This reveue model has ot bee successfully itegrated ito popular P2P applicatios. Usage statistics gatherig, which drives ad-based reveue, is more difficult i the P2P architecture because it is highly distributed. Additioally, as discussed i Chapter 15, the distributed architecture ad depedece o user-cotrolled ed system resources mea that it is more difficult to provide expected levels of service quality. Oe might the argue that P2P is primarily a low barrier of etry, eablig techology for ew applicatios. Oce prove, such applicatios ca be replaced with easier-to-maage ad more reliable cliet/server techology. But P2P offers a uiquely self-scalig architecture, i which icreased participatio icreases the capacity of the system. This plus the cost differetial eabled by usig ed-system resources suggest that P2P should always be able to provide certai types of services at a cost level ot achievable by cliet/server architectures. Further, popular applicatios that have reached a critical mass have bee historically difficult to retire or replace, udermiig the practicality of replacig P2P applicatios with correspodig cliet/server oes. Whe a user iteracts with a applicatio, what features tell the user that it is implemeted usig a P2P overlay? There is o sigle fuctio that ca t be implemeted i both architectures. But as the usage grows to a global commuity with sigificat iformatio sharig, the differece i scalig properties meas that, ideally, P2P should be able to support a much larger degree of iteractio i terms of umber of cocurret users ad amout of cotet that ca be mutually

19 12 CHAPTER 1 Itroductio shared. For example, it is widely kow that Web search egies idex oly a portio of the Web. Could a P2P architecture eable Web search to cover more cotet ad provide more powerful sematic search capability? The aswers to such questios will impact the future of P2P architectures. Is P2P ¼ Piracy? P2P is ot the first techological iovatio to have its iitial success due to somewhat less tha ideal use. If P2P file sharig had from the start icluded ways for cotet owers to obtai licesig reveue, the role of P2P as a trasformatioal techology would ot have bee obscured by the piracy associatio. Certaily, methods exist for protectig licesed cotet that ca be applied i P2P file-sharig systems. Cosequetly, we believe P2P is a disruptive techology that has importat legitimate uses. I the case of music file sharig, early P2P systems demostrated a large market for a ew distributio model ad ew busiess model. This ew distributio model uses global search, exchage of cotet directly betwee ed users, highquality audio, the capability to select idividual tracks, ad the ability to use the cotet o a variety of persoal devices. Further, this distributio model is ot restricted to cotet provided by the major labels. It is a low-barrier-of-etry meas for idepedet artists ad others to publish cotet for cosideratio by a wide audiece, without the requiremet to go through a music publisher. As for the busiess model, paymet for idefiite persoal use of track playback is widely accepted. Subscriptio models have show viability. Others such as ad-drive models are i trial phases. P2P Stregths ad Beefits Much of this book discusses the details of desigig P2P applicatios ad overlays. As a prelude to that, we should cosider the beefits as well as the limitatios of buildig ad deployig a applicatio usig the P2P approach versus covetioal cliet/server or Web-based approaches. Naturally, P2P might ot be the best choice i may cases. A P2P overlay is a collectio of distributed etworked hosts whose resources are available for use by the P2P applicatios associated with the overlay. These resources iclude computatio, etwork capacity, ad file storage. While their host is coected to the overlay, each ed user shares i the cost of operatig the overlay. This cost sharig by the participats lowers the barrier of etry to overlay providers. The low barrier of etry meas that little hardware or etwork ivestmet is eeded to lauch a P2P applicatio. As discussed earlier, the P2P architecture is iheretly self-scalable, sice each ew peer adds additioal capacity to the system. However, the developers of early P2P applicatios soo discovered that ot all peers have equal capacity to cotribute. For example, the host might be relatively limited i terms of CPU speed ad memory capacity. Or the host might be behid a firewall, makig it

20 Motivatio for P2P Applicatios 13 difficult for that peer to participate i the routig algorithm of the overlay. Or the host might be used for other applicatios that cosume much of the available capacity. Cosequetly, some desigs have orgaized peers ito differet categories depedig o their capacity ad reliability. The more capable or super peers might perform all the overlay operatios, whereas the less capable peers play a more limited role. The self-scalig property by itself does t ecessarily traslate ito good performace uder heavy loads sice the load might ot be uiformly distributed across the overlay. To illustrate, cosider the well-kow pheomeo of flash crowds that occurs whe a very popular item is first available at a Website. As word spreads about the availability of this ew item, large umbers of users simultaeously try to retrieve it usig their Web browsers. This creates a sudde ad excessive load o the Web servers that provide the object. Examples of objects that cause flash crowds iclude major ews stories or ew music or video releases by popular artists. Flash crowds ad less dramatic ueve loadig ca also occur i P2P overlays. O the Web, oe techique to redistribute the load is to use Web caches that are distributed aroud the Iteret. Caches are placed alog the request path for a Web page ad cotai copies of objects that have bee recetly retrieved. Whe a browser requests a object, the request is first routed to earby caches. If the object is located there, it will be retured to the browser without the request ever reachig the Web server. Some P2P overlay desigs use a similar approach by keepig copies of objects that have bee retrieved at itermediate peers alog the search path. Whe aother request for the object is routed alog the same path, the itermediate peer will retur the object before the request reaches the origial peer servig the object. As discussed later i Chapter 11, such techiques do t work i all overlays. I additio, as objects lose popularity, a method is eeded to replace old ifrequetly refereced objects with ewer more popular oes. The typical peer lifetime i a P2P overlay is short ad of upredictable duratio. The lifetime of each peer is subject to local decisios of the user ad is outside the cotrol of the overlay desiger. To successfully operate, a overlay must compesate for the variability i peer membership ad dyamic behavior of participatig peers. A key parameter affectig the desig is the average rate at which peers joi ad leave the overlay, or the chur rate. A importat feature of P2P overlays is the ability to self-orgaize i the face of this dyamic behavior. We ll discuss self-orgaizatio further i Chapter 2. Volatility i peer membership effects peer reliability, aother importat property of P2P overlays. I geeral, reliability improves with icreased redudacy. For example, if copies of a object are placed at multiple ureliable peers, it is more likely for some searchig peer to locate the object tha if a sigle ureliable peer stores the object. Likewise, peers eed to idetify a set of eighbors for routig messages to the rest of the overlay. A larger eighbor set ca be useful for icreasig the likelihood that at least oe peer is olie whe a message is to

Domain 1: Designing a SQL Server Instance and a Database Solution

Domain 1: Designing a SQL Server Instance and a Database Solution Maual SQL Server 2008 Desig, Optimize ad Maitai (70-450) 1-800-418-6789 Domai 1: Desigig a SQL Server Istace ad a Database Solutio Desigig for CPU, Memory ad Storage Capacity Requiremets Whe desigig a

More information

Professional Networking

Professional Networking Professioal Networkig 1. Lear from people who ve bee where you are. Oe of your best resources for etworkig is alumi from your school. They ve take the classes you have take, they have bee o the job market

More information

ODBC. Getting Started With Sage Timberline Office ODBC

ODBC. Getting Started With Sage Timberline Office ODBC ODBC Gettig Started With Sage Timberlie Office ODBC NOTICE This documet ad the Sage Timberlie Office software may be used oly i accordace with the accompayig Sage Timberlie Office Ed User Licese Agreemet.

More information

IT Support. 020 8269 6878 n www.premierchoiceinternet.com n support@premierchoiceinternet.com. 30 Day FREE Trial. IT Support from 8p/user

IT Support. 020 8269 6878 n www.premierchoiceinternet.com n support@premierchoiceinternet.com. 30 Day FREE Trial. IT Support from 8p/user IT Support IT Support Premier Choice Iteret has bee providig reliable, proactive & affordable IT Support solutios to compaies based i Lodo ad the South East of Eglad sice 2002. Our goal is to provide our

More information

(VCP-310) 1-800-418-6789

(VCP-310) 1-800-418-6789 Maual VMware Lesso 1: Uderstadig the VMware Product Lie I this lesso, you will first lear what virtualizatio is. Next, you ll explore the products offered by VMware that provide virtualizatio services.

More information

Domain 1 - Describe Cisco VoIP Implementations

Domain 1 - Describe Cisco VoIP Implementations Maual ONT (642-8) 1-800-418-6789 Domai 1 - Describe Cisco VoIP Implemetatios Advatages of VoIP Over Traditioal Switches Voice over IP etworks have may advatages over traditioal circuit switched voice etworks.

More information

ContactPro Desktop for Multi-Media Contact Center

ContactPro Desktop for Multi-Media Contact Center CotactPro Desktop for Multi-Media Cotact Ceter CCT CotactPro (CP) is the perfect solutio for the aget desktop i a Avaya multimedia call ceter eviromet. CotactPro empowers agets to efficietly serve customers

More information

BaanERP. BaanERP Windows Client Installation Guide

BaanERP. BaanERP Windows Client Installation Guide BaaERP A publicatio of: Baa Developmet B.V. P.O.Box 143 3770 AC Bareveld The Netherlads Prited i the Netherlads Baa Developmet B.V. 1999. All rights reserved. The iformatio i this documet is subject to

More information

Authentication - Access Control Default Security Active Directory Trusted Authentication Guest User or Anonymous (un-authenticated) Logging Out

Authentication - Access Control Default Security Active Directory Trusted Authentication Guest User or Anonymous (un-authenticated) Logging Out FME Server Security Table of Cotets FME Server Autheticatio - Access Cotrol Default Security Active Directory Trusted Autheticatio Guest User or Aoymous (u-autheticated) Loggig Out Authorizatio - Roles

More information

3G Security VoIP Wi-Fi IP Telephony Routing/Switching Unified Communications. NetVanta. Business Networking Solutions

3G Security VoIP Wi-Fi IP Telephony Routing/Switching Unified Communications. NetVanta. Business Networking Solutions 3G Security VoIP Wi-Fi IP Telephoy Routig/Switchig Uified Commuicatios NetVata Busiess Networkig Solutios Opportuity to lower Total Cost of Owership ad improve Retur o Ivestmet The ADTRAN Advatage ADTRAN

More information

Domain 1 Components of the Cisco Unified Communications Architecture

Domain 1 Components of the Cisco Unified Communications Architecture Maual CCNA Domai 1 Compoets of the Cisco Uified Commuicatios Architecture Uified Commuicatios (UC) Eviromet Cisco has itroduced what they call the Uified Commuicatios Eviromet which is used to separate

More information

June 3, 1999. Voice over IP

June 3, 1999. Voice over IP Jue 3, 1999 Voice over IP This applicatio ote discusses the Hypercom solutio for providig ed-to-ed Iteret protocol (IP) coectivity i a ew or existig Hypercom Hybrid Trasport Mechaism (HTM) etwork, reducig

More information

STUDENTS PARTICIPATION IN ONLINE LEARNING IN BUSINESS COURSES AT UNIVERSITAS TERBUKA, INDONESIA. Maya Maria, Universitas Terbuka, Indonesia

STUDENTS PARTICIPATION IN ONLINE LEARNING IN BUSINESS COURSES AT UNIVERSITAS TERBUKA, INDONESIA. Maya Maria, Universitas Terbuka, Indonesia STUDENTS PARTICIPATION IN ONLINE LEARNING IN BUSINESS COURSES AT UNIVERSITAS TERBUKA, INDONESIA Maya Maria, Uiversitas Terbuka, Idoesia Co-author: Amiuddi Zuhairi, Uiversitas Terbuka, Idoesia Kuria Edah

More information

Evaluating Model for B2C E- commerce Enterprise Development Based on DEA

Evaluating Model for B2C E- commerce Enterprise Development Based on DEA , pp.180-184 http://dx.doi.org/10.14257/astl.2014.53.39 Evaluatig Model for B2C E- commerce Eterprise Developmet Based o DEA Weli Geg, Jig Ta Computer ad iformatio egieerig Istitute, Harbi Uiversity of

More information

A Guide to Better Postal Services Procurement. A GUIDE TO better POSTAL SERVICES PROCUREMENT

A Guide to Better Postal Services Procurement. A GUIDE TO better POSTAL SERVICES PROCUREMENT A Guide to Better Postal Services Procuremet A GUIDE TO better POSTAL SERVICES PROCUREMENT itroductio The NAO has published a report aimed at improvig the procuremet of postal services i the public sector

More information

A Network Monitoring System with a Peer-to- Peer Architecture

A Network Monitoring System with a Peer-to- Peer Architecture A Network Moitorig System with a Peer-to- Peer Architecture Paulo Salvador ad Rui Valadas Uiversity of Aveiro Istitute of Telecommuicatios Summary Motivatio Peer-to-peer architecture System elemets Data

More information

Online Banking. Internet of Things

Online Banking. Internet of Things Olie Bakig & The Iteret of Thigs Our icreasigly iteretcoected future will mea better bakig ad added security resposibilities for all of us. FROM DESKTOPS TO SMARTWATCHS Just a few years ago, Americas coducted

More information

Configuring Additional Active Directory Server Roles

Configuring Additional Active Directory Server Roles Maual Upgradig your MCSE o Server 2003 to Server 2008 (70-649) 1-800-418-6789 Cofigurig Additioal Active Directory Server Roles Active Directory Lightweight Directory Services Backgroud ad Cofiguratio

More information

client communication

client communication CCH Portal cliet commuicatio facig today s challeges Like most accoutacy practices, we ow use email for most cliet commuicatio. It s quick ad easy, but we do worry about the security of sesitive data.

More information

leasing Solutions We make your Business our Business

leasing Solutions We make your Business our Business if you d like to discover how Bp paribas leasig Solutios Ca help you to achieve your goals please get i touch leasig Solutios We make your Busiess our Busiess We look forward to hearig from you you ca

More information

Digital Enterprise Unit. White Paper. Web Analytics Measurement for Responsive Websites

Digital Enterprise Unit. White Paper. Web Analytics Measurement for Responsive Websites Digital Eterprise Uit White Paper Web Aalytics Measuremet for Resposive Websites About the Authors Vishal Machewad Vishal Machewad has over 13 years of experiece i sales ad marketig, havig worked as a

More information

Engineering Data Management

Engineering Data Management BaaERP 5.0c Maufacturig Egieerig Data Maagemet Module Procedure UP128A US Documetiformatio Documet Documet code : UP128A US Documet group : User Documetatio Documet title : Egieerig Data Maagemet Applicatio/Package

More information

Baan Service Master Data Management

Baan Service Master Data Management Baa Service Master Data Maagemet Module Procedure UP069A US Documetiformatio Documet Documet code : UP069A US Documet group : User Documetatio Documet title : Master Data Maagemet Applicatio/Package :

More information

Agency Relationship Optimizer

Agency Relationship Optimizer Decideware Developmet Agecy Relatioship Optimizer The Leadig Software Solutio for Cliet-Agecy Relatioship Maagemet supplier performace experts scorecards.deploymet.service decide ware Sa Fracisco Sydey

More information

TruStore: The storage. system that grows with you. Machine Tools / Power Tools Laser Technology / Electronics Medical Technology

TruStore: The storage. system that grows with you. Machine Tools / Power Tools Laser Technology / Electronics Medical Technology TruStore: The storage system that grows with you Machie Tools / Power Tools Laser Techology / Electroics Medical Techology Everythig from a sigle source. Cotets Everythig from a sigle source. 2 TruStore

More information

How to use what you OWN to reduce what you OWE

How to use what you OWN to reduce what you OWE How to use what you OWN to reduce what you OWE Maulife Oe A Overview Most Caadias maage their fiaces by doig two thigs: 1. Depositig their icome ad other short-term assets ito chequig ad savigs accouts.

More information

PUBLIC RELATIONS PROJECT 2016

PUBLIC RELATIONS PROJECT 2016 PUBLIC RELATIONS PROJECT 2016 The purpose of the Public Relatios Project is to provide a opportuity for the chapter members to demostrate the kowledge ad skills eeded i plaig, orgaizig, implemetig ad evaluatig

More information

Supply Chain Management

Supply Chain Management Supply Chai Maagemet LOA Uiversity October 9, 205 Distributio D Distributio Authorized to Departmet of Defese ad U.S. DoD Cotractors Oly Aim High Fly - Fight - Wi Who am I? Dr. William A Cuigham PhD Ecoomics

More information

Domain 1: Configuring Domain Name System (DNS) for Active Directory

Domain 1: Configuring Domain Name System (DNS) for Active Directory Maual Widows Domai 1: Cofigurig Domai Name System (DNS) for Active Directory Cofigure zoes I Domai Name System (DNS), a DNS amespace ca be divided ito zoes. The zoes store ame iformatio about oe or more

More information

SOCIAL MEDIA. Keep the conversations going

SOCIAL MEDIA. Keep the conversations going SOCIAL MEDIA Keep the coversatios goig Social media is where most of the world is. It is therefore a ope source of cosumer data, a chael of commuicatio ad a platform for establishig relatioships with customers.

More information

One Goal. 18-Months. Unlimited Opportunities.

One Goal. 18-Months. Unlimited Opportunities. 18 fast-track 18-Moth BACHELOR S DEGREE completio PROGRAMS Oe Goal. 18-Moths. Ulimited Opportuities. www.ortheaster.edu/cps Fast-Track Your Bachelor s Degree ad Career Goals Complete your bachelor s degree

More information

CREATIVE MARKETING PROJECT 2016

CREATIVE MARKETING PROJECT 2016 CREATIVE MARKETING PROJECT 2016 The Creative Marketig Project is a chapter project that develops i chapter members a aalytical ad creative approach to the marketig process, actively egages chapter members

More information

Agenda. Outsourcing and Globalization in Software Development. Outsourcing. Outsourcing here to stay. Outsourcing Alternatives

Agenda. Outsourcing and Globalization in Software Development. Outsourcing. Outsourcing here to stay. Outsourcing Alternatives Outsourcig ad Globalizatio i Software Developmet Jacques Crocker UW CSE Alumi 2003 jc@cs.washigto.edu Ageda Itroductio The Outsourcig Pheomeo Leadig Offshore Projects Maagig Customers Offshore Developmet

More information

Security Functions and Purposes of Network Devices and Technologies (SY0-301) 1-800-418-6789. Firewalls. Audiobooks

Security Functions and Purposes of Network Devices and Technologies (SY0-301) 1-800-418-6789. Firewalls. Audiobooks Maual Security+ Domai 1 Network Security Every etwork is uique, ad architecturally defied physically by its equipmet ad coectios, ad logically through the applicatios, services, ad idustries it serves.

More information

Domain 1: Identifying Cause of and Resolving Desktop Application Issues Identifying and Resolving New Software Installation Issues

Domain 1: Identifying Cause of and Resolving Desktop Application Issues Identifying and Resolving New Software Installation Issues Maual Widows 7 Eterprise Desktop Support Techicia (70-685) 1-800-418-6789 Domai 1: Idetifyig Cause of ad Resolvig Desktop Applicatio Issues Idetifyig ad Resolvig New Software Istallatio Issues This sectio

More information

Smart Connected Products & The Internet of Things

Smart Connected Products & The Internet of Things Smart Coected Products & The Iteret of Thigs Who we are Taget delivers Talet Globally. Established for 40 years we specialise i delivery of iovative & tailored talet solutios to customers aroud the world.

More information

CCH CRM Books Online Software Fee Protection Consultancy Advice Lines CPD Books Online Software Fee Protection Consultancy Advice Lines CPD

CCH CRM Books Online Software Fee Protection Consultancy Advice Lines CPD Books Online Software Fee Protection Consultancy Advice Lines CPD Books Olie Software Fee Fee Protectio Cosultacy Advice Advice Lies Lies CPD CPD facig today s challeges As a accoutacy practice, maagig relatioships with our cliets has to be at the heart of everythig

More information

Comparing Credit Card Finance Charges

Comparing Credit Card Finance Charges Comparig Credit Card Fiace Charges Comparig Credit Card Fiace Charges Decidig if a particular credit card is right for you ivolves uderstadig what it costs ad what it offers you i retur. To determie how

More information

For customers Key features of the Guaranteed Pension Annuity

For customers Key features of the Guaranteed Pension Annuity For customers Key features of the Guarateed Pesio Auity The Fiacial Coduct Authority is a fiacial services regulator. It requires us, Aego, to give you this importat iformatio to help you to decide whether

More information

How to read A Mutual Fund shareholder report

How to read A Mutual Fund shareholder report Ivestor BulletI How to read A Mutual Fud shareholder report The SEC s Office of Ivestor Educatio ad Advocacy is issuig this Ivestor Bulleti to educate idividual ivestors about mutual fud shareholder reports.

More information

Your organization has a Class B IP address of 166.144.0.0 Before you implement subnetting, the Network ID and Host ID are divided as follows:

Your organization has a Class B IP address of 166.144.0.0 Before you implement subnetting, the Network ID and Host ID are divided as follows: Subettig Subettig is used to subdivide a sigle class of etwork i to multiple smaller etworks. Example: Your orgaizatio has a Class B IP address of 166.144.0.0 Before you implemet subettig, the Network

More information

Commercial Real Estate Women Network

Commercial Real Estate Women Network Commercial Real Estate Wome Network About CREW Network Fouded i 1989, CREW Network is the idustry s premier busiess etworkig orgaizatio dedicated to ifluecig the success of the commercial real estate idustry

More information

Unicenter TCPaccess FTP Server

Unicenter TCPaccess FTP Server Uiceter TCPaccess FTP Server Release Summary r6.1 SP2 K02213-2E This documetatio ad related computer software program (hereiafter referred to as the Documetatio ) is for the ed user s iformatioal purposes

More information

Making training work for your business

Making training work for your business Makig traiig work for your busiess Itegratig core skills of laguage, literacy ad umeracy ito geeral workplace traiig makes sese. The iformatio i this pamphlet will help you pla for ad build a successful

More information

GOOD PRACTICE CHECKLIST FOR INTERPRETERS WORKING WITH DOMESTIC VIOLENCE SITUATIONS

GOOD PRACTICE CHECKLIST FOR INTERPRETERS WORKING WITH DOMESTIC VIOLENCE SITUATIONS GOOD PRACTICE CHECKLIST FOR INTERPRETERS WORKING WITH DOMESTIC VIOLENCE SITUATIONS I the sprig of 2008, Stadig Together agaist Domestic Violece carried out a piece of collaborative work o domestic violece

More information

Prescribing costs in primary care

Prescribing costs in primary care Prescribig costs i primary care LONDON: The Statioery Office 13.50 Ordered by the House of Commos to be prited o 14 May 2007 REPORT BY THE COMPTROLLER AND AUDITOR GENERAL HC 454 Sessio 2006-2007 18 May

More information

E-Plex Enterprise Access Control System

E-Plex Enterprise Access Control System Eterprise Access Cotrol System Egieered for Flexibility Modular Solutio The Eterprise Access Cotrol System is a modular solutio for maagig access poits. Employig a variety of hardware optios, system maagemet

More information

TIAA-CREF Wealth Management. Personalized, objective financial advice for every stage of life

TIAA-CREF Wealth Management. Personalized, objective financial advice for every stage of life TIAA-CREF Wealth Maagemet Persoalized, objective fiacial advice for every stage of life A persoalized team approach for a trusted lifelog relatioship No matter who you are, you ca t be a expert i all aspects

More information

INVESTMENT PERFORMANCE COUNCIL (IPC) Guidance Statement on Calculation Methodology

INVESTMENT PERFORMANCE COUNCIL (IPC) Guidance Statement on Calculation Methodology Adoptio Date: 4 March 2004 Effective Date: 1 Jue 2004 Retroactive Applicatio: No Public Commet Period: Aug Nov 2002 INVESTMENT PERFORMANCE COUNCIL (IPC) Preface Guidace Statemet o Calculatio Methodology

More information

How To Find FINANCING For Your Business

How To Find FINANCING For Your Business How To Fid FINANCING For Your Busiess Oe of the most difficult tasks faced by the maagemet team of small busiesses today is fidig adequate fiacig for curret operatios i order to support ew ad ogoig cotracts.

More information

Ideate, Inc. Training Solutions to Give you the Leading Edge

Ideate, Inc. Training Solutions to Give you the Leading Edge Ideate, Ic. Traiig News 2014v1 Ideate, Ic. Traiig Solutios to Give you the Leadig Edge New Packages For All Your Traiig Needs! Bill Johso Seior MEP - Applicatio Specialist Revit MEP Fudametals Ad More!

More information

Optimize your Network. In the Courier, Express and Parcel market ADDING CREDIBILITY

Optimize your Network. In the Courier, Express and Parcel market ADDING CREDIBILITY Optimize your Network I the Courier, Express ad Parcel market ADDING CREDIBILITY Meetig today s challeges ad tomorrow s demads Aswers to your key etwork challeges ORTEC kows the highly competitive Courier,

More information

facing today s challenges As an accountancy practice, managing relationships with our clients has to be at the heart of everything we do.

facing today s challenges As an accountancy practice, managing relationships with our clients has to be at the heart of everything we do. CCH CRM cliet relatios facig today s challeges As a accoutacy practice, maagig relatioships with our cliets has to be at the heart of everythig we do. That s why our CRM system ca t be a bolt-o extra it

More information

A guide to School Employees' Well-Being

A guide to School Employees' Well-Being A guide to School Employees' Well-Beig Backgroud The public school systems i the Uited States employ more tha 6.7 millio people. This large workforce is charged with oe of the atio s critical tasks to

More information

optimise your investment in Microsoft technology. Microsoft Consulting Services from CIBER

optimise your investment in Microsoft technology. Microsoft Consulting Services from CIBER optimise your ivestmet i Microsoft techology. Microsoft Cosultig Services from Microsoft Cosultig Services from MICROSOFT CONSULTING SERVICES ca help with ay stage i the lifecycle of adoptig Microsoft

More information

Information for Programs Seeking Initial Accreditation

Information for Programs Seeking Initial Accreditation Iformatio for Programs Seekig Iitial Accreditatio Aswers to Frequetly- Asked-Questios (from www.abet.org/ew-to-accreditatio/) Assurig Quality l Stimulatig Iovatio This documet iteds to aswer may of the

More information

Trustwave Leverages OEM Partnerships to Deepen SIEM Market Penetration

Trustwave Leverages OEM Partnerships to Deepen SIEM Market Penetration Trustwave Leverages OEM Parterships to Deepe SIEM Market Peetratio Accelerated lauch of ew security appliaces delivers reveue growth with assist from UNICOM Egieerig ad Dell OEM Solutios Itroductio Trustwave

More information

Investing in Stocks WHAT ARE THE DIFFERENT CLASSIFICATIONS OF STOCKS? WHY INVEST IN STOCKS? CAN YOU LOSE MONEY?

Investing in Stocks WHAT ARE THE DIFFERENT CLASSIFICATIONS OF STOCKS? WHY INVEST IN STOCKS? CAN YOU LOSE MONEY? Ivestig i Stocks Ivestig i Stocks Busiesses sell shares of stock to ivestors as a way to raise moey to fiace expasio, pay off debt ad provide operatig capital. Ecoomic coditios: Employmet, iflatio, ivetory

More information

9.8: THE POWER OF A TEST

9.8: THE POWER OF A TEST 9.8: The Power of a Test CD9-1 9.8: THE POWER OF A TEST I the iitial discussio of statistical hypothesis testig, the two types of risks that are take whe decisios are made about populatio parameters based

More information

UK Grant-making Trusts and Foundations

UK Grant-making Trusts and Foundations SECTOR INSIGHT UK Grat-makig Trusts ad Foudatios 2015 Tom Trayor Dr Catherie Walker dsc directory of social chage Published by the Directory of Social Chage (Registered Charity o. 800517 i Eglad ad Wales)

More information

The Canadian Council of Professional Engineers

The Canadian Council of Professional Engineers The Caadia Coucil of Professioal Egieers Providig leadership which advaces the quality of life through the creative, resposible ad progressive applicatio of egieerig priciples i a global cotext Egieerig

More information

Verizon Wireless Broadband Network Connectivity and Data Transport Solutions. Verizon Wireless White Paper

Verizon Wireless Broadband Network Connectivity and Data Transport Solutions. Verizon Wireless White Paper Verizo Wireless Broadbad Network Coectivity ad Data Trasport Solutios Verizo Wireless White Paper Cotets 1. Itroductio......................................................................................

More information

France caters to innovative companies and offers the best research tax credit in Europe

France caters to innovative companies and offers the best research tax credit in Europe 1/5 The Frech Govermet has three objectives : > improve Frace s fiscal competitiveess > cosolidate R&D activities > make Frace a attractive coutry for iovatio Tax icetives have become a key elemet of public

More information

Enhancing Oracle Business Intelligence with cubus EV How users of Oracle BI on Essbase cubes can benefit from cubus outperform EV Analytics (cubus EV)

Enhancing Oracle Business Intelligence with cubus EV How users of Oracle BI on Essbase cubes can benefit from cubus outperform EV Analytics (cubus EV) Ehacig Oracle Busiess Itelligece with cubus EV How users of Oracle BI o Essbase cubes ca beefit from cubus outperform EV Aalytics (cubus EV) CONTENT 01 cubus EV as a ehacemet to Oracle BI o Essbase 02

More information

Modified Line Search Method for Global Optimization

Modified Line Search Method for Global Optimization Modified Lie Search Method for Global Optimizatio Cria Grosa ad Ajith Abraham Ceter of Excellece for Quatifiable Quality of Service Norwegia Uiversity of Sciece ad Techology Trodheim, Norway {cria, ajith}@q2s.tu.o

More information

Business Application Services. Business Applications that provide value to your enterprise.

Business Application Services. Business Applications that provide value to your enterprise. Busiess Applicatio Services Busiess Applicatios that provide value to your eterprise. Sesiple s expertise ca help orgaizatio decode the performace issues ad trasform them ito valuable beefits that meet

More information

PENSION ANNUITY. Policy Conditions Document reference: PPAS1(7) This is an important document. Please keep it in a safe place.

PENSION ANNUITY. Policy Conditions Document reference: PPAS1(7) This is an important document. Please keep it in a safe place. PENSION ANNUITY Policy Coditios Documet referece: PPAS1(7) This is a importat documet. Please keep it i a safe place. Pesio Auity Policy Coditios Welcome to LV=, ad thak you for choosig our Pesio Auity.

More information

Telecom. White Paper. Actionable Intelligence in the SDN Ecosystem: Optimizing Network Traffic through FRSA

Telecom. White Paper. Actionable Intelligence in the SDN Ecosystem: Optimizing Network Traffic through FRSA Telecom White Paper Actioable Itelligece i the SDN Ecosystem: Optimizig Network Traffic through FRSA About the Authors Sumit Kapoor Sumit is a solutio architect i the telecom busiess uit at Tata Cosultacy

More information

Privacy Guide for Small Businesses: The Basics

Privacy Guide for Small Businesses: The Basics Office of the Privacy Commissioer of Caada PIPEDA Privacy Guide for Small Busiesses: The Basics Privacy is the best policy Hadlig privacy cocers correctly ca help improve your orgaizatio s reputatio. Whe

More information

Introducing Your New Wells Fargo Trust and Investment Statement. Your Account Information Simply Stated.

Introducing Your New Wells Fargo Trust and Investment Statement. Your Account Information Simply Stated. Itroducig Your New Wells Fargo Trust ad Ivestmet Statemet. Your Accout Iformatio Simply Stated. We are pleased to itroduce your ew easy-to-read statemet. It provides a overview of your accout ad a complete

More information

Analyzing Longitudinal Data from Complex Surveys Using SUDAAN

Analyzing Longitudinal Data from Complex Surveys Using SUDAAN Aalyzig Logitudial Data from Complex Surveys Usig SUDAAN Darryl Creel Statistics ad Epidemiology, RTI Iteratioal, 312 Trotter Farm Drive, Rockville, MD, 20850 Abstract SUDAAN: Software for the Statistical

More information

In nite Sequences. Dr. Philippe B. Laval Kennesaw State University. October 9, 2008

In nite Sequences. Dr. Philippe B. Laval Kennesaw State University. October 9, 2008 I ite Sequeces Dr. Philippe B. Laval Keesaw State Uiversity October 9, 2008 Abstract This had out is a itroductio to i ite sequeces. mai de itios ad presets some elemetary results. It gives the I ite Sequeces

More information

Best of security and convenience

Best of security and convenience Get More with Additioal Cardholders. Importat iformatio. Add a co-applicat or authorized user to your accout ad you ca take advatage of the followig beefits: RBC Royal Bak Visa Customer Service Cosolidate

More information

Flood Emergency Response Plan

Flood Emergency Response Plan Flood Emergecy Respose Pla This reprit is made available for iformatioal purposes oly i support of the isurace relatioship betwee FM Global ad its cliets. This iformatio does ot chage or supplemet policy

More information

Radio Dispatch Systems

Radio Dispatch Systems Radio Dispatch Systems ZETRON DISPATCH SOLUTIONS: AT THE CENTER OF YOUR CRITICAL OPERATIONS Your dispatch system is the ceterpoit through which your key operatios are coordiated ad cotrolled. That s why

More information

SANLAM DIRECT MARKETING DIVISION BELLVILLE, SOUTH AFRICA

SANLAM DIRECT MARKETING DIVISION BELLVILLE, SOUTH AFRICA JANSSEN RESEARCH FOUNDATION SANLAM DIRECT MARKETING DIVISION BELLVILLE, SOUTH AFRICA AFRICA EXCELLENCE AWARDS: WORKFLOW, MERIT EXECUTIVE SUMMARY The life isurace busiess i South Africa is curretly uder

More information

Determining the sample size

Determining the sample size Determiig the sample size Oe of the most commo questios ay statisticia gets asked is How large a sample size do I eed? Researchers are ofte surprised to fid out that the aswer depeds o a umber of factors

More information

INVESTMENT PERFORMANCE COUNCIL (IPC)

INVESTMENT PERFORMANCE COUNCIL (IPC) INVESTMENT PEFOMANCE COUNCIL (IPC) INVITATION TO COMMENT: Global Ivestmet Performace Stadards (GIPS ) Guidace Statemet o Calculatio Methodology The Associatio for Ivestmet Maagemet ad esearch (AIM) seeks

More information

where: T = number of years of cash flow in investment's life n = the year in which the cash flow X n i = IRR = the internal rate of return

where: T = number of years of cash flow in investment's life n = the year in which the cash flow X n i = IRR = the internal rate of return EVALUATING ALTERNATIVE CAPITAL INVESTMENT PROGRAMS By Ke D. Duft, Extesio Ecoomist I the March 98 issue of this publicatio we reviewed the procedure by which a capital ivestmet project was assessed. The

More information

The analysis of the Cournot oligopoly model considering the subjective motive in the strategy selection

The analysis of the Cournot oligopoly model considering the subjective motive in the strategy selection The aalysis of the Courot oligopoly model cosiderig the subjective motive i the strategy selectio Shigehito Furuyama Teruhisa Nakai Departmet of Systems Maagemet Egieerig Faculty of Egieerig Kasai Uiversity

More information

Inland American s Exit

Inland American s Exit Report by UNITE HERE, December 2013 Becky Perrie, Sa Fracisco Research bperrie@uitehere.org/415-553-3276 Ilad America s Exit Will Ilad America Real Estate Trust take advatage of what it calls its very

More information

Predictive Modeling Data. in the ACT Electronic Student Record

Predictive Modeling Data. in the ACT Electronic Student Record Predictive Modelig Data i the ACT Electroic Studet Record overview Predictive Modelig Data Added to the ACT Electroic Studet Record With the release of studet records i September 2012, predictive modelig

More information

Handling. Collection Calls

Handling. Collection Calls Hadlig the Collectio Calls We do everythig we ca to stop collectio calls; however, i the early part of our represetatio, you ca expect some of these calls to cotiue. We uderstad that the first few moths

More information

Advancement FORUM. www.acmaweb.org/advancement CULTIVATING LEADERS IN CASE MANAGEMENT

Advancement FORUM. www.acmaweb.org/advancement CULTIVATING LEADERS IN CASE MANAGEMENT H E A L T H C A R E D E L I V E R Y S Y S T E M C A S E M A N A G E M E N T E D U C A T I O N Advacemet FORUM CULTIVATING LEADERS IN CASE MANAGEMENT DATES AND LOCATIONS LOS ANGELES, CA DECEMBER 11 DALLAS,

More information

INDEPENDENT BUSINESS PLAN EVENT 2016

INDEPENDENT BUSINESS PLAN EVENT 2016 INDEPENDENT BUSINESS PLAN EVENT 2016 The Idepedet Busiess Pla Evet ivolves the developmet of a comprehesive proposal to start a ew busiess. Ay type of busiess may be used. The Idepedet Busiess Pla Evet

More information

CCH Accounts Production

CCH Accounts Production CCH Accouts Productio accouts productio facig today s challeges Preparig statutory ad fiacial accouts is a core activity for our practice, as it is for may professioal firms. Although legislatio ad accoutig

More information

*The most important feature of MRP as compared with ordinary inventory control analysis is its time phasing feature.

*The most important feature of MRP as compared with ordinary inventory control analysis is its time phasing feature. Itegrated Productio ad Ivetory Cotrol System MRP ad MRP II Framework of Maufacturig System Ivetory cotrol, productio schedulig, capacity plaig ad fiacial ad busiess decisios i a productio system are iterrelated.

More information

A GUIDE TO BUILDING SMART BUSINESS CREDIT

A GUIDE TO BUILDING SMART BUSINESS CREDIT A GUIDE TO BUILDING SMART BUSINESS CREDIT Establishig busiess credit ca be the key to growig your compay DID YOU KNOW? Busiess Credit ca help grow your busiess Soud paymet practices are key to a solid

More information

CHAPTER 3 THE TIME VALUE OF MONEY

CHAPTER 3 THE TIME VALUE OF MONEY CHAPTER 3 THE TIME VALUE OF MONEY OVERVIEW A dollar i the had today is worth more tha a dollar to be received i the future because, if you had it ow, you could ivest that dollar ad ear iterest. Of all

More information

Designing Incentives for Online Question and Answer Forums

Designing Incentives for Online Question and Answer Forums Desigig Icetives for Olie Questio ad Aswer Forums Shaili Jai School of Egieerig ad Applied Scieces Harvard Uiversity Cambridge, MA 0238 USA shailij@eecs.harvard.edu Yilig Che School of Egieerig ad Applied

More information

RISK TRANSFER FOR DESIGN-BUILD TEAMS

RISK TRANSFER FOR DESIGN-BUILD TEAMS WILLIS CONSTRUCTION PRACTICE I-BEAM Jauary 2010 www.willis.com RISK TRANSFER FOR DESIGN-BUILD TEAMS Desig-builD work is icreasig each quarter. cosequetly, we are fieldig more iquiries from cliets regardig

More information

QUADRO tech. PST Flightdeck. Put your PST Migration on autopilot

QUADRO tech. PST Flightdeck. Put your PST Migration on autopilot QUADRO tech PST Flightdeck Put your PST Migratio o autopilot Put your PST Migratio o Autopilot A moder aircraft hardly remids its pilots of the early days of air traffic. It is desiged to eable flyig as

More information

Telecom. White Paper. Prioritizing Mice Flows in Software Defined Networks for Enhanced Monetization and User Experience

Telecom. White Paper. Prioritizing Mice Flows in Software Defined Networks for Enhanced Monetization and User Experience Telecom White Paper Prioritizig Mice Flows i Software Defied Networks for Ehaced Moetizatio ad User Experiece About the Authors Partha Datta Partha Datta has bee workig with Tata Cosultacy Services (TCS)

More information

Amendments to employer debt Regulations

Amendments to employer debt Regulations March 2008 Pesios Legal Alert Amedmets to employer debt Regulatios The Govermet has at last issued Regulatios which will amed the law as to employer debts uder s75 Pesios Act 1995. The amedig Regulatios

More information

Recovery time guaranteed heuristic routing for improving computation complexity in survivable WDM networks

Recovery time guaranteed heuristic routing for improving computation complexity in survivable WDM networks Computer Commuicatios 30 (2007) 1331 1336 wwwelseviercom/locate/comcom Recovery time guarateed heuristic routig for improvig computatio complexity i survivable WDM etworks Lei Guo * College of Iformatio

More information

Bio-Plex Manager Software

Bio-Plex Manager Software Multiplex Suspesio Array Bio-Plex Maager Software Extract Kowledge Faster Move Your Research Forward Bio-Rad cotiues to iovate where it matters most. With Bio-Plex Maager 5.0 software, we offer valuable

More information

CCH Accountants Starter Pack

CCH Accountants Starter Pack CCH Accoutats Starter Pack We may be a bit smaller, but fudametally we re o differet to ay other accoutig practice. Util ow, smaller firms have faced a stark choice: Buy cheaply, kowig that the practice

More information

summary of cover CONTRACT WORKS INSURANCE

summary of cover CONTRACT WORKS INSURANCE 1 SUMMARY OF COVER CONTRACT WORKS summary of cover CONTRACT WORKS INSURANCE This documet details the cover we ca provide for our commercial or church policyholders whe udertakig buildig or reovatio works.

More information