CS 294 -3: Distributed Service Architectures in Converged Networks Randy H. Katz Computer Science Division Electrical Engineering and Computer Science Department University of California Berkeley, CA 94720 -1776 1
Outline • • • What is this Course About? Technology Trends Evolution of the Internet Business Trends Implications and Issues Summary and Conclusions 2
Outline • • • What is this Course About? Technology Trends Evolution of the Internet Business Trends Implications and Issues Summary and Conclusions 3
Traditional “Networking” Course • All about protocols and the OSI seven layers – – – – Protocol details: link-state vs. distance vector, TCP Protocol layering Multiaccess technology Switching and routing Naming Error control Flow control & scheduling Special topics like multicast and mobility 4
What is New? • New things you can do inside the network • Connecting end-points to “services” with processing embedded in the network fabric • Not protocols but “agents, ” executing in places in the network • Location-aware, data format aware • Controlled violation of layering necessary! • Distributed architecture aware of network topology • No single technical architecture likely to dominate: think overlays, system of systems 5
Definition of Terms • Converged Networks – – Public Switched Telephone Network (PSTN) Internet/Public Switched Data Network (PSDN) Mobile Internet Converged Structure? • Distributed Service Architecture – Services » “-Ility” connectivity » New call “features” » Infrastructure services » Enables distributed applications 6
What is this Course About? • Emerging, yet still developing, view of a new kind of communications-oriented service architecture in a highly heterogeneous environment – Rapid development/deployment of new services & apps – Delivered to radically different end devices (phone, computer, info appliance) over diverse access networks (PSTN, LAN, Wireless, Cellular, DSL, Cable, Satellite) – Exploiting Internet-based technology core: clients/server, applications level routers, TCP/IP protocols, Web/XML formats – Beyond traditional “call processing” model: client-proxyserver plus application-level partitioning – Built upon a new business model being driven by the evolution of the Internet: traditional “managed” networks and services versus emerging “overlay” networks and services structured on top of and outside of the above 7
Course Structure • Seminar! We learn from each other! – Avoid traditional lecture-oriented course – More student-led presentations, discussions – Project will be the group design and evaluation of a distributed service architecture – 2 Units/2 Hours per week – Every student will develop materials and lead one hour discussion on a selected area of technology; to be written up by mid-semester as a “term paper” – Project: depending on class size, we will have collaborating and competing teams develop a design and evaluation for future converged network service architecture – 20% Term Paper – 30% Class Discussion/Presentation – 50% Class Project 8
• • • Relevant Technologies (Partial List!) PSTN architecture: AIN, SS-7 SLAs 3 GPP/GPRS/Edge Voice over IP with SIP Internet Multimedia Architecture (RTSP, SIP, SAP, RTP/RTCP, IPv 6, IP Mobility, Diff. Serv, Multicast) Sync. ML Parlay, JTAPI WAP Symbian/Embedded OS Sun ONE, . Net, Corba, TINA SMS/MMS + Other Messaging Platforms MGCP • SIP Instant Messaging + Presence Leveraging • Mobile Location Services • WAP • Radius/Diameter/Single Sign On • BGP • MPLS • Core vs. Access Networking Technologies • Mobey Formum • Operator Wireless LAN • DRM, PKI • SCPTP/IETF Sigtran • Architecture of Internet Data Centers and NAPs 9
Nokia’s Mobile World View Network Environment Internet Intranet 2 G/3 G Messaging Browsing Rich Call Identity/ Addressing Interaction URL Email Phone # 10
Nokia’s Mobile Service Matrix Content Information Entertainment News Banking & Finance Buy & Sell Travel Music TV Lifestyle Fun Games Astrology Dating Comms Messaging Productivity Business Organizers Intranet & Extranet Access E-Mail Personal Assistants FAX Tools Rich Call Misc Info Mgmt Enterprise Comms VPNs Telematics 11
Nokia’s Mobile Internet “Business Architecture” End Users Developers Content Providers Service Providers Consumption Connection Consumption User Interface Applications Rich Call Browsing Msg Application Gateways Rich Call Browsing Msg Applications Rich Call Browsing Msg Middleware OS Network Hardware 12
Application Layer Other and 3 rd Party Applications Email App Browser App Phone App Instant Messaging Application Streaming Application Programming Interface Msg Support Rich Call Support Browser Support Application Development Interfaces Mobile Internet Layer App Framework and UI Support App Protocols SDK Interfaces Network Interface SDK Libraries Network Protocols Platform Applications Interfaces Platform Layer I/O Drivers OS Core Link Layer Drivers I/O Hardware Processors & Memory Network Hardware 13
Nokia’s m. Platform Architecture Provisioning Self-Care Operator Care Billing Data Collection Sys Monitoring Perf Monitoring Statistics Common Enabling Application Functions Presentation Manager Operator Manager Audit Manager (Billing) Navigation Manager Notification Manager Security Manager Session Manager Personalization Manager Scenario Manager Access Functions Application Interface Operational Support Subscriber Service Access Control Authentication Access Control Process WAP & PDA Handling Proxy Firewall Network Connectivity Load Balancing 14
One Operator’s Viewpoint Pricing Structure Customer Service HLR Distribution Packaging Marketing & Sales Billing Apps Charging 3 rd Party Apps Services Content Support Systems Service Domain Data Center Data Storage BS Radio Access BS Network Spectrum Qo. S Capacity On-Demand Processing Cap Local Radio Access Transport Core Network Capacity On-Demand 15
ICEBERG Architecture Access Network Plane PSTN GSM IAP IAP ICEBERG Network Plane IAP A SF i. POP IAP NY i. POP IAP SF i. POP B NY i. POP Clearing House ISP Plane CA PR PAC APC NMS Pager ISP 1 ISP 2 • i. POP: Clustered computing environ. • Call Agent: handles signaling, one per device per call party ISP 3 • Name Mapping Service: Maps ICEBERG unique ID service end point • Preference Registry / Personal Activity Coordinator: user profile / user tracking • Automatic Path Creation service: creates transcoding datapath between endpoints 16
Possible High Level “Layered” View of Service Architecture Prototype Applications: Universal In-Box, Context-Aware UI, Group Collaboration Context-Awareness Services: Activity Tracking/Coordination, Preferences Specification/Interpretation Adaptation Services: Introspection, Tacit Information Extraction/Organization Wide-Area Services: Discovery, Mobility, Trust, Availability Performance Measurement and Monitoring “Core” Wide-Area Network Edge/Access Networks 17
Outline • • • What is this Course About? Technology Trends Evolution of the Internet Business Trends Implications and Issues Summary and Conclusions 18
Technology Trends • Computing – Convergence, Divergence, Scale • Networks – Internet vs. Telephone Network – Wireless/Mobile Access • Services – E-commerce, M-commerce/M-transactions (i. Mode), Content – Messaging as a major application (P 2 P, P 2 M, M 2 M) • Architecture – Integrated (“Closed”) vs. Composed (“Open”) Content, Distribution, Access Architecture – Managed vs. Overlay Networks and Services – Competitive vs. Cooperative Service Providers 19
Internet Growth Million Servers Annual Growth Rate > 50% Million U. S. Surfers Annual Growth Rate > 20% The Industry Standard, 2 July 2001 20
Convergence? First Color TV Broadcast, 1953 HBO Launched, 1972 Telephone, 1876 Interactive TV, 1990 Early Wireless Phones, 1978 Computer + Modem 1957 First PC Altair, 1974 IBM PC, 1981 Handheld Portable Phones, 1990 Apple IBM Mac, Powerbook, Thinkpad, 1984 1990 1992 Eniac, 1947 HP Palmtop, 1991 Pentium PC, 1993 Apple Newton, 1993 Red Herring, 10/99 21
Divergence! Atari Home Pong, 1972 Pentium PC, 1993 Game Consoles Personal Digital Assistants Digital VCRs (Ti. Vo, Replay. TV) Communicators Smart Telephones E-Toys (Furby, Aibo) Network Computer, 1996 Free PC, 1999 Sega Dreamcast, 1999 Internet-enabled Smart Phones, 1999 Pentium II PC, 1997 Apple i. Mac, 1998 Palm VII PDA, 1999 Proliferation of diverse end devices and access networks Red Herring, 10/99 22
“X-Internet” Beyond the PC Internet Computers Internet Users 93 Million Today’s Internet 407 Million Automobiles 663 Million Telephones 1. 5 Billion X-Internet Electronic Chips 30 Billion Forrester Research, May 2001 23
“X-Internet” Beyond the PC Millions PC Internet X Internet Year Forrester Research, May 2001 24
The Shape of Things Now • Siemens SL 45 – A cellular phone with voice command, voice dialing, intelligent text for short messages – An MP 3 player & headset – A digital voice recorder – Supports “Mobile Internet” with a built-in WAP Browser – Can store » 45 minutes of music » 5 hours of voice notes » “Unlimited” addresses/phone numbers 25
The Shape of Things Now • Kyocera QCP 6035 – Palm OS/CDMA – Palm PIM Applications – Supports “Mobile Internet” with a built-in WAP Browser – 8 MBytes 26
The Shape of Things to Come • Toyota Pod Concept Car – Co-designed with Sony – Detects driver’s skill level and adjust suspension – Detects driver’s mood (pulse rate, perspiration), compensates for road rage and incorporates a mood meter (happy vs. angry face) – Inter-pod wireless LAN to communicate intentions between vehicles, such as passing – Individual entertainment stations for each passenger 27
The i. Mode Story: It is About Services • 27 M Internet-capable cell phone subscribers (10/01); 50 K i. Mode Web Sites • World’s largest ISP, first to deploy 3 G “Freedom of Multimedia Access” (FOMA) • Not just about Japanese teenagers Applications Used User Ages Economist Magazine, 13 Oct 2001 28
After the PC … True “Convergence” • Not just about gadgets or access technologies • About services and applications, and how the network can best support them • Increasing, not decreasing, diversity • Bottlenecks moving from core towards edge • Enabled by computing embedded in communications fabric: wide-area, topologyaware, distributed computing 29
What is the Internet? “It’s the TCP/IP Protocol Stack” Applications • Applications Middleware Services “Narrow Waist” TCP/IP Transport Services and Representation Standards Network Technology Substrate Access Technologies Open Data Network Bearer Service Where is the next “narrow waist”? – Web – Email – Video/Audio • TCP/IP • Access Technologies – Ethernet (LAN) – Wireless (LMDS, WLAN, Cellular) – Cable – ADSL – Satellite 30
Telephony Evolution • Mobility/Wireless driving end-to-end digitization of the telephony system – Shift towards IP-based infrastructure (Nokia “All-IP” Architecture) • Converged Services – AT&T » Cell Phone, Telephone, ISP, Video on Demand (Cable) » Universal Billing Systems – Sprint: $0. 05/min local/long distance, wired/wireless • Computer-Telephony Integration – Call Centers, Software-based PBXs, PSTN By-Pass – Consumer-to-Business E-commerce (e. g. , Lands End) – Speech-Enabled Services (e. g. , “Concierge”) 31
Internet vs. Telephone Net • Strengths – Intelligence at ends – Decentralized control – Operates over heterogeneous access technologies • Weaknesses – No differential service – Variable performance delay – New functions difficult to add since end nodes must be upgraded – No trusted infrastructure • Strengths – No end-point intelligence – Heterogeneous devices – Excellent voice performance • Weaknesses – Achieves performance by overallocating resources – Difficult to add new services to “Intelligent Network” due to complex call model – Expensive approach for reliability 32
Cellular Services Most Often Requested After basic wireless telephony service • • • Call Forwarding Paging Internet/E-Mail Traffic/Weather Conference Calling News 37% 33% 24% Data 15% Applications 13% 3% Source: CTIA Web Page Peter D. Hart Research Associates, March 1997 33
Services and Applications: E-Commerce • Consumer Services – – – Consumer-driven Qo. S: improved Web access “experience” Converged digital video + web content (e. g. , HVML) Unified billing: pay-per-view movie plus ad-induced pizza purchase Content delivery: file mover/software upgrades/digital audio/video Infrastructure storage: back-up, photos, mp 3 s, videos, TV tapings • Consumer-to-Business Services – Web-based + (IP-based) Telephone – New kinds of integrated call centers: e. g. , Lands End • M-Commerce – Location-sensitive ad insertion – Unified billing for telecom access + purchases 34
Outline • • • What is this Course About? Technology Trends Evolution of the Internet Business Trends Implications and Issues Summary and Conclusions 35
The ARPANet SRI 940 UCSB IBM 360 IMPs Utah PDP 10 UCLA Sigma 7 • Paul Baran – RAND Corp, early 1960 s – Communications networks that would survive a major enemy attack • ARPANet: Research vehicle for “Resource Sharing Computer Networks” BBN team that implemented the interface message processor – 2 September 1969: UCLA first node on the ARPANet – December 1969: 4 nodes connected by phone lines 36
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ARPANet Evolves into Internet ARPANet SATNet PRNet 1965 TCP/IP 1975 Web Hosting Multiple ISPs Internet 2 Backbone Internet Exchanges NSFNet Deregulation & ISP Commercialization ASP AIP WWW 1985 1995 2005 Application Hosting ASP: Application Service Provider AIP: Application Infrastructure Provider (e-commerce tookit, etc. ) 38
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Digex Backbone Qwest IP Backbone (Late 1999) GTE Internetworking Backbone Parallel Backbones 41
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Network “Cloud” 43
Regional Nets + Backbone Regional Net Backbone Regional Net LAN 44
Backbones + NAPs + ISPs ISP ISP NAP Backbones Business ISP LAN NAP ISP Consumer ISP LAN Dial-up 45
Core Networks + Access Networks DSL Always on Cable Head Ends @home Covad Cingular Cell LAN NAP Core Networks NAP ISP Satellite Fixed Wireless Sprint LAN AOL LAN Dial-up 46
Computers Inside the Core DSL Always on Cable Head Ends @home Covad Cingular Cell LAN NAP ISP Satellite Fixed Wireless Sprint LAN AOL LAN Dial-up 47
Interconnected World: Agile or Fragile? • Baltimore Tunnel Fire 18 July 2001 – “… The fire also damaged fiber optic cables, slowing Internet service across the country, …” – “… Keynote Systems … says the July 19 Internet slowdown was not caused by the spreading of Code Red. Rather, a train wreck in a Baltimore tunnel that knocked out a major UUNet cable caused it. ” – “PSINet, Verizon, World. Com and Above. Net were some of the bigger communications companies reporting service problems related to ‘peering, ’ methods used by Internet service providers to hand traffic off to others in the Web's infrastructure. Traffic slowdowns were also seen in Seattle, Los Angeles and Atlanta, possibly resulting from re-routing around the affected backbones. ” – “The fire severed two OC-192 links between Vienna, VA and New York, NY as well as an OC-48 link from, D. C. to Chicago. … Metromedia routed traffic around the fiber break, relying heavily on switching centers in Chicago, Dallas, and D. C. ” 48
Service-Level Peering • Need common architecture for different vendors to create components and work with one another while still competing • Some Observations – IP originally designed for cooperative administrative environments – BGP “recently” retrofitted to architecture to manage administrative relationships – How to design in managed peering from first principles? • Solution Based on Redirection Above IP – Define the redirection architecture – New client/infrastructure protocol & API (a la DNS) – Do so in backward compatible way 49
Application-Specific Overlays E. g. , solve the multicast management and peering problems by moving up the protocol stack Isolated multicast clouds multicast cloud multicast cloud Traditional unicast peering Steve Mc. Canne 50
Application-Level Servers/Routers Solve the multicast management and peering problems by moving up the protocol stack Steve Mc. Canne 51
Outline • • • What is this Course About? Technology Trends Evolution of the Internet Business Trends Implications and Issues Summary and Conclusions 52
Layerized Internet Service Business Model Applications (Portals, E-Commerce, E-Tainment, Media) Appl Infrastructure Services (Distribution, Caching, Searching, Hosting) AIP ISV Application-specific Servers (Streaming Media, Transformation) ASP Internet Data Centers ISP CLEC Application-specific Overlay Networks (Multicast Tunnels, Mgmt Svrcs) Global Packet Network Internetworking (Connectivity) 53
A New Kind of Internet Web Site Caching Comparison Shopping Interactive TV Guide Local Ad Insertion Streaming Media Application Services Customer J Terminal Equipment & Access Network Applications Regional Communications PC, Set-top Box. Smart Phone, Game Console, E-toys Web, E-mail, Chat, E-commerce, E-tainment ISP Web Hosting Server “Platform” ISP Caching Search Engine Server Computing Wide-Area Communications Infrastructure Services High Performance Backbone 54
Open vs. Closed Access to Services Covad DSL Time/Warner Roadrunner AOL Dial-up AT&T Cable Access Cable, DSL, MMDS, LMDS, Satellite CNCX AOL @Home Local Network Management ISP Williams AOL @Home Routing & Distribution Backbone Provider Web AOL/Netscape Time/Warner Excite Content Portal Web Sites • Closed end-to-end pipe: optimized performance • But companies developing compelling infrastructure technology that any content provider or ISP can adopt • Closed system can’t benefit from these 55
From Network Management to Service Management Service Level Control Server Load Balancing • Server and site availability • Balanced server and site load Advanced Traffic Management • Rapid change • Network and application flexibility • Scalability • Complex site administration • Rapid problem diagnosis/ isolation • Service level measurement • Multi-tier resource monitoring • Preferential Services • Resource Provisioning • Self-tuning • Problem prevention Chris Morino, Resonate 56
Service Reliability is Critical • ISP connection down • LAN segment overloaded Network Failure 18. 2% • CPU overloaded • NIC failure • Process hung • Slowed database performance Applications Failure 28. 5% Source: IDC Systems Server Failure 20% OS Failure 24. 6% Administration 8. 7% Chris Morino, Resonate 57
Competition vs. Cooperation • Internet Service Providers: Competition – Peering for packet transport: BGP protocol – Charging based on traffic volumes ISP A Peering Point Hot Potato Routing Peering Point ISP B 58
Mobile Internet Might Be Different Than Wired Internet • Wireless is a smarter pipe – Location-awareness – UI dictates need for personalization, mediation • Clear billing authority: it’s the access provider – People actually do pay for transport – Reverse billing allows content provider to charge for service • Peering as a necessity – – Operators provide local service Roaming agreements provide basis for service peering Well understood arrangements for settlements New economies driving towards shared network deployment • Person-to-Person communications is a killer app • Microsoft’s non-monopoly 59
Cooperation and Peering • 3 G Spectrum Auctions: 150 billion ECU; Capital outlays may match spectrum expenses, all before first revenue • New business models in Mobile Networks – Compelling services make the difference – Collaborate on deployment of physical network – Compete on provisioning of services • Peering For More Than Connectivity – Horizontal architecture of services on top of networks – Virtual Home Environments – Relationships between operators, billing agents, service providers 60
Any Way to Build a Network? • Partitioning of frequencies independent of actual subscriber density – Successful operator oversubscribe resources, while less popular providers retain excess capacity – Different flavor of roaming: among collocated/competing service providing • Duplicate antenna sites – Serious problem given community resistance • Redundant backhaul networks – Limited economies of scale 61
The Case for Horizontal Architectures “The new rules for success will be to provide one part of the puzzle and to cooperate with other suppliers to create the complete solutions that customers require. . [V]ertical integration breaks down when innovation speeds up. The big telecoms firms that will win back investor confidence soonest will be those with the courage to rip apart their monolithic structure along functional layers, to swap size for speed and to embrace rather than fear disruptive technologies. ” The Economist Magazine, 16 December 2000 62
Feasible Alternative: Horizontal Competition vs. Vertical Integration • Service Operators “own” the customer, provide “brand”, issue/collect the bills • Independent Backhaul Operators • Independent Antenna Site Operators • Independent Owners of the Spectrum • Microscale auctions/leases of network resources • Emerging concept of Virtual Operators 63
Business as Usual: Vertical Integration PBMS Sprint Access Network Backhaul Network PSTN Network (Multiservice Provider today) Internet (Multiservice Provider today) • Each operator owns own frequencies, cell sites, backhaul network 64
Business Unusual: Horizontal Competition Sprint “leases” frequencies from PBMS, on-demand, based on the density of its subscribers “Mom&Pop” Cell Site Operators Access Network Backhaul Network PSTN Network Backhaul Network Internet 65
Virtual Operator • MVNO: Virgin Mobile and One 2 One in UK – Distinguish based on marketing and billing plan innovations – VM competes for subscribers but uses One 2 One’s network • “Operators without subscribers”: local premises deploy own access infrastructure – Better coverage/more rapid build out of network – Deployments in airports, hotels, conference centers, office buildings, campuses, … • Overlay service provider (e. g. , PBMS) vs. organizational service provider (e. g. , UCB IS&T) – Single bill/settle with service participants – Operator Wireless LAN • Support for ensemble devices – Cell Phone + Wall Camera & Display 66
Outline • • • What is this Course About? Technology Trends Evolution of the Internet Business Trends Implications and Issues Summary and Conclusions 67
What will be the Next Generation of Driving Applications? • Location-aware/context-aware information delivery and presentation – Extends Uni. In-Box: loc-based, exploits calendar info – Mediation to translate formats • IP Telephony, Packet Vo. D, Teleconferencing – Streaming media, multicast-based – Bandwidth, latency, jitter, lose rate constraints – Clearinghouse provisioning • Event Delivery for Distributed Applications – Performance/reliability constrained messaging – Management of Content Delivery Networks, Distributed Service architecture? • Interactive Games? Distributed Storage (Ocean. Store)? Telemetry? 68
What Will Be the Next Generation Operational Environment? • Virtual Operators/Service Provider (VOSP) – Provide service to end users with no server/network infrastructure of own – Independent “Path” providers (e. g. , ISPs) and Server providers (e. g. , Internet Data Centers) – Many-to-many relationship between VOSP and Path/Server Providers • Confederated Service Provider – Service-level peering: sharing of paths and servers to deploy end-to-end service with performance and reliability constraints • Note: Akamai runs “the world’s largest service network” without owning a network! 69
Alternative Operational Environments • Confederation Model – Providers share (limited) information about topology, server location, path performance – Cooperatively collect internal information and share • Overlay Model – Reverse-engineer topology and intra-cloud performance – Collection done by brokers outside of the cloud • SLAs, Verification, Maintenance of Trust Relationships different in the two models • Is there an operational/performance advantage to the Confederation Model? 70
Open Issues/Questions • Traditional Overlay Networks – Server (“Application Level Router”) Placement » For scaling, reliability, load balancing, latency » Where? Network topology discovery: WAN Core, Metro/Regional, Access Networks – Choice of Inter-Server “Paths” » For server-to-server latency/bandwidth/loss rate » Predictable/verifiable network performance (intra-ISP SLA) – Redirection Mechanisms » Random, round-robin, load-informed redirection » Net vs. server as bottleneck 71
Open Issues/Questions • Performance-constrained Service Placement – Separation of Service, Server, Service Path » Assume “Server Centers” known, can be “discovered” (how does Ocean. Store deal with this? ), or register with a Service Placement Service (SPS) » How is Service named, described, performance constraints expressed, and registered? » How is app/service-specific performance measured and made known to Service Placement Service? – Brokering between Server Centers and Service Creator, Path Provider and Service Creator • If core network bandwidth becomes infinite and “free”, does it matter where services are placed? – Latency reduction vs. economies of centralized management 72
Emerging Reference Architecture Constraint Specification Distributed Application Marshal Resources Based on Economic Constraints Service Registration Service Placement Service Path Broker Server Broker Perf Measurement Service Verify SLAs Path Provider (ISP Cloud) Adapt Service Redirection Pricing Service Server Registration Advertisement Registration Path Provider (ISP Cloud) Server Center Provider 73
Methodological Framework • Problem: performing scaled, wide-area networking studies in the current Internet environment • Possible Solution: Wide-area Network Emulation – Virtual WAN (VWAN) on Large-scale Multicomputer Testbeds – Build operational model on top of VWAN » Traffic generation and measurement infrastructure » Build Confederation and Overlay operational models » What part of mechanisms for measurement, negotiation, registration, redirection, etc. the same and which are different? 74
Outline • • • What is this Course About? Technology Trends Evolution of the Internet Business Trends Implications and Issues Summary and Conclusions 75
Cable Modem Connectivity and Processing Premisesbased Access Networks LAN Transit Net Premisesbased Core Networks WLAN Private Peering Transit Net WLAN Operatorbased Cell Regional Internet Datacenter NAP Public Peering Data Voice Analog Transit Net H. 323 RAS H. 323 PSTN DSLAM Data Voice Wireline Regional 76
Challenges for Converged Networks • Services spanning access networks, to achieve high performance and manage diversity of end devices • Not about specific Information Appliances • Builds on the New Internet: multiple applicationspecific “overlay” networks, with new kinds of service -level peering • Pervasive support for services within “intelligent” networks – – Automatic replication Document routing to caches Compression & mirroring Data transformation 77
Managing Edge Versus Core Services • Wide-area bandwidth efficiency • Increasing b/w over access networks, but impedance mismatch between core and access nets • Fast response time (and more predictable) • Opportunity to untegrate localized content • Associated with client (actually ISP), not server • Examples: – – – Caching: exploits response time, b/w efficiency, high local b/w Filtering: form of local content transformation Internet TV: b/w efficiency, high local b/w, predictable response Transformation: adapt content for end user/diverse access devices Software Rental: sxploits high local b/w Games, chat rooms, …. 78
Yielding a New Research Agenda • New Definition of “Quality of Service” – Perceived quality depends on services in the network – Manage caches, redirection, NOT bandwidth – Enable incorporation of localized content • Bandwidth Issues – – Tier 1 ISP backbones rapidly moving towards OC 192 (9. 6 gbs!) Better interconnection: hops across ASs decreasing over time Emerging broadband access networks: cable, DSL, . . . End-to-end latency/server load dominate performance – – IP Multicast, DNS, … Rethinking the End-to-End Principle Service/content-level peering, just like routing-level peering Secure end-to-end connection compatible with service model? • Supporting Old Services in the New Internet 79
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