The Bay Area Research Wireless Access Network (BARWAN) New Ideas • Wireless Overlay Internetworking – “Overlay” IP extensions to Mobile IP –  Low Latency Inter-subnet Handoffs – High Thruput Reliable Transport – Class-Based Queuing Link Management – Subnet Bandwidth Load Balancing • Client-Proxy-Server Architecture – Bandwidth-aware Data Type Adaptation –  Web & A/V Data Types over Wireless – Proxy-Aware API, Kerberos Integration – Delivery Class Abstraction – Scalable Wireline Processing for Mobiles High-tier Low-tier Satellite High Mobility Low Mobility Wide Area Regional Area Local Area R. H. Katz & E. A. Brewer, UC Berkeley Subcontractor: Hughes Research Labs Impact • Fundamental technology for 21st century battlefield communications: support for wide diversity of hybrid & asymmetric link technologies, and end device display & computation capabilities • Seamless roaming & application adaptation across 3–4 orders of magnitude of wireless b/w and latency (10 kbps to 10 mbps, 1 ms to 1 s) • Demonstrate network & application techniques able to scale to support 10s of data users/room, 100s/building, 1000s/facility, 10000s/metro, and 100000s/region Schedule Measure & Eval Wireless Ovrly Technologies Demo in-building ovrlys & h/os with dynamic b/w alloc Demo wide-area ovrlys & low latency h/os w/ subnet load balancing Aug 95 Start Aug 96 Aug 97 Aug 98 End Early Prototype Proxies (1-10 users) Proto Scaled Proxies (100-1000 Users) Scaled Proxies (1000-10000 Users) Large Scale Scalability Demonstrations Initial Architectural Specification Scaled Architectural Specification

Randy H. Katz and Eric A. Brewer The Bay Area Research Wireless Access Network: Towards a Wireless Overlay Internetworking Architecture Satellite Regional Area Low-tier High-tier Local Area Wide Area High Mobility Low Mobility Randy H. Katz and Eric A. Brewer Computer Science Division, EECS Department University of California, Berkeley, CA 94720-1776 Subcontractor: Hughes Malibu Research Laboratories

Presentation Outline Retreat Purpose and Agenda Project Objectives, Motivation, Contributions Project Status and GloMo Demo Participation Review Project Plan New Directions Summary and Conclusions

Presentation Outline Retreat Purpose and Agenda Project Objectives, Motivation, Contributions Project Status and GloMo Demo Participation Review Project Plan New Directions Summary and Conclusions

Retreat Goals & Technology Transfer Industrial Collaborators Government Sponsors Friends UC Berkeley Project Team Hughes Researchers People Project Status Work in Progress Prototype Technology Early Access to Technology Promising Directions Reality Check Feedback

Retreat Purpose To celebrate the completion of one project: BARWAN (Daedalus/GloMop) Highlight the technical successes Discuss the lessons learned Kick off a new ambitious project: NINJA Builds on experience in scalable processing platforms (NOWs), agent architectures, ubiquitous connectivity, multimedia toolkits A middleware-intensive approach to “active networking” User-centered applications: Computer-telephony integration and services Personal information management Smart spaces Form new industrial consortium for technical follow on

BARWAN/Hughes Team Networking Applications Technical Support Hari Balakrishnan (Reliable Transport) Tom Henderson (Satellite-based Transport & Routing Protocols) Todd Hodes (Service Discovery) Giao Nguyen (Channel Scaling) Venkat Padmanabhan (Sessions-Transport Interface) Mark Stemm (Performance Discovery) Helen Wang (Vertical Handoff) Applications Yatin Chawathe (Proxy Architecture/MASH) Armando Fox (Proxy Architecture) Steve Gribble (Scalable Servers) Technical Support Brian Shiratsuki (System Admin) Keith Sklower (Sys Programming) Admin Support Terry Lessard Smith Bob Miller Hughes Malibu Research Laboratory Son Dao Yongguang Zhang Dante De Lucia Srini Seshan got his PhD and is a researcher at IBM Research Elan Amir got his PhD and is starting a company Tao Ye finished her MS and went to JavaSoft Daniel Jiang went to Daimler Benz Research Laboratory Hari Balakrishnan will be an Assistant Professor at MIT Armando Fox will be an Assistant Professor at Stanford Venkat Padmanabhan is considering offers from leading industrial research labs

BARWAN Sponsors and Participants DARPA GloMo Program Rob Ruth, DARPA PM Kevin Mills, DARPA PM/NIST SRI Industrial Supporters Daimler Benz Ericsson (Reiner Ludwig, Visiting Industrial Fellow) Fuji Xerox Palo Alto Labs HRL (Hughes/Raytheon) IBM Metricom Toshiba (Masahiro Takagi, Visiting Industrial Fellow) Friends Lucent, Motorola, Packeteer, Philips, Rutgers, Sandia, Sprint

Retreat Schedule Wednesday, June 10: 0800 - 1130 Travel from Berkeley to Granlibbakkan 1200 - 1330 Lunch 1330 - 1430 Project Overview and Retrospective, Randy Katz 1430 - 1630 Senior Student Research Talks: Transport Issues Hari Balakrishnan: “Challenges to Reliable Data Transport Protocols over Heterogeneous Wireless Networks” Venkat Padmanabhan: “Addressing the Challenges of Web Data Transport” 1630 - 1830 Break 1830 - 1930 Dinner 1930 - 2030 Senior Student Research Talks: Proxy Architecture Armando Fox: “Building Scalable, Composable, Adaptive Internet Services With TACC” 2030 - Distributed Interactive Collaboration (aka Riven)

Retreat Schedule Thursday, June 11: 0730 - 0830 Breakfast 0830 - 1030 Recent Progress Presentations Mark Stemm: “Benefits of Content Negotiation in HTTP” Tom Henderson: “Datagram Routing for Next Generation Satellite Systems” Giao Nguyen: “Channel Dependent Link Scheduling” Yatin Chawathe: “Proxy Load Balancing” 1030 - 1100 Break 1100 - 1200 Ninja Overview, Eric Brewer 1200 - 1600 Lunch/Long Break 1200 - 1400 Special Faculty/Sponsor Meeting* * to discuss opportunity to establish an Internet Systems Research Group at Berkeley

Retreat Schedule Thursday, June 11: 1600 - 1900 Ninja Mini-Retreat, Eric Brewer I-Space: Steve Gribble, Mark Stemm, Matt Walsh ICEBERG Architecture: Anthony Joseph, B. R. Badrinath Multi-Formfactor Documents using XML: Todd Hodes Service Discovery and Path Creation: Eric Brewer Code Transformation: Steve Gribble 1900 - 2030 Dinner 2030 - 2200 Poster Session 2100 - Distributed Problem Solving Ninjutsu is a stealth and espionage-oriented art which saw its greatest development in the 13th to early 17th centuries in Japan. Its practitioners, the ninja, were warrior-assassin-spies; most belonged to the Iga and Koga mountain clans. They were the supreme reconnaissance experts and saboteurs of their day.

Retreat Schedule Friday, June 12: 0730 - 0830 Breakfast 0830 - 1000 Six Month Planning Session, Anthony Joseph 1000 - 1030 Break & Check-out 1030 - 1200 Sponsor/Friends Feedback Session, Randy Katz 1200 - 1300 Lunch 1300 - Depart Granlibakkan

Presentation Outline Retreat Purpose and Agenda Project Objectives, Motivation, Contributions Project Status and GloMo Demo Participation Review Project Plan New Directions Summary and Conclusions

Heterogeneous Mobile Computing “People and their machines should be able to access information and communicate with each other easily and securely, in any medium or combination of media -- voice, data, image, video, or multimedia -- any time, anywhere, in a timely, cost-effective way.” G. Heilmeier, 1992 Access Anytime, Anywhere Wide-Area Coverage Scalable Processing Highly Available Operation Easily Transparent Access Localized Service Securely Global Authentication Any Medium Multimedia: Audio/Video/Graphics Timely Performance Cost Effective Heterogeneous Support via Proxies Three Overarching Strategies: Heterogeneous Wireless Networks Network Optimization Dynamic Adaptation

Daedalus/GloMop Architectural Components Mobile Applications Proxy Agents Location-Dependent Services Transport (Asymmetric, Heterogeneous, Lossy Links) “Sessions” Overlay IP (Mobile IP + Overlays) Mobile IP Beacons Net Connection Monitoring; Net-Appl Interface; ELN; Wireless LAN Packet Radio Wire- Less Cable DBS Sub- Net Cellular Data ATM IP Snoop Agent Link Scheduling

Daedalus/GloMop Architecture

Problems Solved by Daedalus/GloMop Archtecture Seamless mobility within and across heterogeneous networks Transparent and automatic network connections Low latency handoffs yielding smooth audio and video while roaming Reliable transport based on TCP Interoperation with legacy servers Hides performance losses due to wireless losses, asymmetries Automatic discovery and configuration of local network services Universal remote control with dynamic UIs

Problems Solved by Daedalus/GloMop Archtecture Thin Client Support Dynamic adaptation of content Computational support in the infrastructure for resource-poor clients Scalable Infrastructure Services Cluster-based computing Scalable, extensible, available Layered programming model for new service creation

Wireless Overlay Networks Theatre of Operations Rear Echelons Bases, Depots, Ranges Command Centers Training Centers

Major Contributions Overlay Networking and Vertical Handoff Design Constraints Low Latency Handoff Power Conservation Bandwidth Conservation Handoff Mechanisms Modified Mobile IP (“Overlay IP”) Local-Area Multicast for Low Latency Horizontal H/O Fast Beaconing, Header Doublecasting for Vertical H/O Policy-based Vertical H/O

Asymmetric & Heterogeneous Access High Bandwidth – Command Post – Disaster Relief – Remote Clinic – Organization w/poor Internet connectivity Local Subnet Low Bandwidth

Major Contributions Reliable Data Transport over Wireless Networks Wireless Packet Losses Snoop Protocol: agent-based approach for local retransmission Asymmetric Networks Sources of asymmetry: bandwidth, latency, losses Managing the ACK stream while maintaining good pacing of data packets Ack congestion control Ack filtering Ack reconstruction Sender adaptation Acks-first scheduling Link Sharing for Wireless LANs, Cable Model Nets, GPRS Class-based queuing plus channel-state dependent packet scheduling

Client-PROXY-Server Architecture Mediates between wireless and wireline environment Ideally executes at “well-connected” boundary of internetwork Manages caches and chooses transport data representations on-the-fly Trade transcoding time against communications time Proxy Well Connected Poorly Connected

Major Contributions Proxy Architecture Adaptation to variation in hardware, software, and network capabilities of end devices Thin client display and processing limitations Network connectivity and security processing limits On-Demand Image Transformation Web browsing with graphics on PalmPilot Postscript viewing on PDAs via on-demand transformation to HTML Real-time Video Transcoding MBone video over ISDN, transcoded from 400 kbps to 128 kbps Multicast-based white-board sessions on the PalmPilot

Scalable Proxy Architecture $ html gif jpg $ Cache control $ Front End PTM Control Panel To Internet NOW Cluster SAN (high speed) $ Cache partition Utility (10baseT) ... Datatype-specific distiller Coordination bus

Major Contributions Proxy Architecture Measuring changes in network characteristics: SPAND Piggyback measurements on top of existing traffic Share performance information among user community Scalable cluster-based proxies NOW Platform/Scalable Network Service Load balancing, availability/fault tolerance, system monitoring/logging TACC (Transformation, Aggregation, Caching, Customization) Programming Model Composition of stateless data transformation and content aggregation modules Caching of original, post-aggregation, post-transformation products Service Workers providing control interfaces and presentation of TACC modules

Key Research Themes Dynamic Adaptation Cross-Layer Optimization Agent-Based Processing Soft State

Key Research Themes Dynamic Adaptation Varying network conditions Adaptive mechanisms for TCP Channel dependent class-based queuing Vertical handoff Client and network heterogeneity On-demand format conversion Real-time video transcoding based on network conditions Dynamic quality/performance tradeoffs Dynamic generation of customized UIs for small devices

Key Research Themes Cross-Layer Optimization Explicit violation of OSI protocol stack Physical layer quality information to trigger handoffs Handoff information to trigger application-layer adaptation Transport layer information to trigger link layer retransmission Explicit link layer loss vs. congestion loss information to drive sender adaptation Network-level performance information allows applications and proxies to tune content

Key Research Themes Agent-Based Processing Method by which new capabilities can be inserted into the network Agents break end-to-end connections, enabling introduction of new protocols/formats/processing while still supporting legacy end points Network Mobility agents for vertical handoff TCP processing agents to deal with losses and asymmetric connections Applications Support Proxy agent Real-time gateway agent

Key Research Themes Soft State Definition: any state that aids performance, adds capabilities but is not essential for correctness Major advantage: tremendously simplifies recovery Extensively used in all elements of the agent architecture Snoop Agent Soft state cache of recent unacknowledged TCP packets Permits local retransmission without violating TCP’s end-to-end semantics TCP Fast Start and Sessions Use recently cached connection state to “fast start” new connections SPAND Performance Database TranSend Proxy Distillation caches Worker soft state eases recovery and load balancing

Major Software Artifacts TCP Snoop Agent Low-latency Horizontal Handoff Vertical Handoff TCP SACK (Selective Acknowledgement) STP (Satellite Transport Protocol) SPAND Performance Server Service Discovery Services and Remote Control in Soda Hall rtpGW: Real-time protocol gateway for A/V Pythia Proxy Server TranSend Scalable Proxy Server TopGun Wingman Browser for PalmPilot TopGun MediaBoard Charon Indirect Authentication Various software developer kits ns/VINT simulation models

Technology Transfer Proxy Software RTP Gateway Beta TranSend binary distribution available Distributed to UC Davis, SRI Wingman Pilot Browser: 8000 downloads Postman Pilot E-mail: 6000 downloads “Professional” distribution from Proxinet, Inc. RTP Gateway 171 downloads in 1997 Transport Layer Software 100 snoop V1 downloads Linux, FreeBSD, NetBSD ports 222 SACK downloads Ports to NetBSD snoop in daily production use in Reinas wireless network@UCSC Wireless, LAN MAC, and Transport simulation modules widely distributed to VINT community HTTP simulator module for ns: 232 downloads STP simulation scripts for ns: 69 downloads

Presentation Outline Retreat Purpose and Agenda Project Objectives, Motivation, Contributions Project Status and GloMo Demo Participation Review Project Plan New Directions Summary and Conclusions

Project Plan and Status 90% Project Start: 15 Aug 95 (Start + 34 Months) Scalability Scalability 100% Demonstrate via Simulation Ability to Scale to Large Communities of Mobile Users Functionality Functionality 100% Demonstrate Seamless Roaming over Local and Wide Area Early Proof of Concept Implementations Early Proof of Concept Implementations NOWs Local & Wide-Area Wireless Overlays Enhanced E2E Performance Establishment of BARWAN Testbed Establishment of BARWAN Testbed Measure Alternative Overlay Network Performance Extend with Emerging Technologies 100%

BARWAN Testbed DirecPC DBS (1 mbps) Vertical Hand-Off LOS Wireless Cable (6 mbps) DARTNet II CAIRN Metricom Cellular Modem Cellular Packet Data Packet Radio Plus local area RF and IR nets in Soda Hall 10-30 kbps

Military JTF Application-Oriented Demonstration: July 98 DBS Uplink Reachback LEO Rear Area Forward Area 2 Forward Area 1 BDE BN BDE BN RDMP Receive Metachannel Client Geofiltering GeoEmail FreeBSD RDMP Receive Metachannel Client Geofiltering GeoEmail FreeBSD Bengal DB Win 95 RDMP Send Metachannel Server Georouting Sender GeoEmail Image Server FreeBSD ASAMA Net DBS Emulator FreeBSD Bengal DB Win 95 ASAMA Hub Bengal DB Win 95 RDMP Receive Metachannel Client Geofiltering GeoEmail FreeBSD RDMP Receive Metachannel Client Geofiltering GeoEmail FreeBSD Uplink Bengal DB Win 95 SAMA Reacback Net (LEO) Soldier Phone Net Bengal DB Win 95 SAMA Control VXWorks Video GW BSDi LEO Emulator FreeBSD

MASH Video Gateway (H.261-H.261) Video Gateway MASH Latest changes XX XXXX JTF Bengal DB DBGlomo Win 95 1 X ARFOR NTSC Audio DBS Emulator RDMP Send Metachannel server Resource scheduler MASH Georouting sender Image server Web server FreeBSD FreeBSD Local RDMP RDMP Proxy Metachannel client Web browser MASH Geonode/Geohost XGloMo Video Gateway (H.261-H.261) 10Base T Hub 10 Base T Hub 10 Base T Hub FreeBSD A V Video Gateway BSDi 915 MHz (12 kbps/ch Reachback SAMA Control (LEO Emulator) VXWorks SAMA Hub SAMA Tx Win 95 Bengal DB DB GloMo Soldier Radio Geolocation 1 Latest changes Bengal on top of Win 95 vice NT 10 base T hubs vice 100 base T (no 100 base T drivers for FreeBSD) Emulator shown in separate box NOTE ASAMA controller must run on top of Win 95 to share sensor simulation Need both FreeBSD and Win 95 ASAMA drivers 1st BN Net 1 Soldier Radio 10 Base T Win 95 Bengal DB DB GloMo Local RDMP Metachannel client Web browser MASH Geonode XGloMo Soldier Radio 10 Base T FreeBSD A V Downlink To 2nd BDE Geolocation 2

MASH Video Gateway (H.261-H.261) MASH Changes Downlink From 1st Division 2 X 1 MARFOR Win 95 Bengal DB DB GloMo SAMA Tx Local RDMP RDMP Proxy Metachannel client Web browser MASH Geonode/Geohost XGloMo Video Gateway (H.261-H.261) FreeBSD A V 10 Base T Hub 2 Changes 10 Base T vice 100 Base t Win 95 vice NT for Bengal Win 95 Bengal DB DB GloMo Win 95 ASAMA Tx (PCI card) ASAMA Control and ALOHA Multi-sensor Simulation 2nd BN Net ASAMA Rx (PCI card) 915 MHz (4 kbps/ch) Local RDMP Metachannel client Web browser MASH Geonode/Geohost XGloMo FreeBSD A V ASAMA Tx (PCI card) CW Jammer Geolocation 3

Military RDF Application-Oriented Demonstration: July 98 CO BN BN DirecPC Wireless ATM CO CO Disconnected Operations New Affiliation Original affiliation CO Browser GeoFilter GeoEmail FreeBSD Coda Server FreeBSD Coda Server FreeBSD Coda Client FreeBSD DirecPC BSDi Snoop BSDi DirecPC Edge Node Linux Edge Node Linux Special Gateway MMWN Net RDRN ATM Net Web Proxy GeoFilter GeoEmail Linux Browser GeoFilter GeoEmail FreeBSD Security Solaris Special Gateway Security Solaris W W Wings Net Wings Net Wings Net W W W W W W W W W W Coda Client Browser GeoFilter GeoEmail FreeBSD Security Solaris Geofilter GeoEmail Linux Coda Client Browser GeoFilter GeoEmail FreeBSD Security Solaris Geofilter GeoEmail Linux Coda Client Browser GeoFilter GeoEmail FreeBSD Security Solaris Geofilter GeoEmail Linux

Presentation Outline Retreat Purpose and Agenda Project Objectives, Motivation, Contributions Project Status and GloMo Demo Participation Review Project Plan New Directions Summary and Conclusions

Six Month Plan (to June 98) Documentation “A Network Architecture for Heterogeneous Mobile Computing” paper Final architecture document (final clean up stages; released at August end of project) STP Specification (in progress) Proxy SDK completed SPAND SDK Released BARWAN all-inclusive CD-ROM (August end of project) Testbed Integrate and Evaluate GSM Add SPAND performance server Link Layer Implementation of priority-based link sharing (deferred) Simulation studies of cable modems (802.14) Simulation studies of GPRS Transport Evaluation & implementation of TCP sessions and fast-start mechanism Measurements of asymmetric TCP and simulation of alternative loss-recovery mechanisms for Ricochet STP implementation released

Six Month Plan (to June 98) High Level Networking (Initial) design policy-based vertical handoff (completed implementation by August, under continuing industrial sponsorship) Clients that use SPAND to tune proxy adaptation More sophisticated and extensible SPAND performance server (Initial) wide-area service advertisement design (in-progress) Extend co-lab testbed (RVic, Camera control) Proxy/Application Support Complete MediaBoard (in-progress; complete by August) Thin-client partitioning strategy Production versions of new services (in-progress) HTTP content negotiation (abandoned in favor of XML-based metadata schemes) Secure proxy services (secure client-links done at Proxinet)

Original Research Plan 9/95 - 8/96 9/96 - 8/97 9/97 - 8/98

DARPA GloMo Program Goals FY 96 Adaptive Mobile Internet Services Location Transparent Computing FY 97 Demo B/W Adaptive MM Node Demo Advanced Mobile Networking FY 98 Demo Multimedia Conferencing Demo Continuous Mobility Daedalus/BARWAN Program Measure/eval overlay networking tech Design overlay network architecture Design proxy architecture, API, toolkit Prototype proxies for image, video, maps Design Scalable Proxies/Proxy Trans Mgr Arch for “Remote Collaboration by Proxy” Overlay IP and Vertical Handoff Reliable transport for hetero/asym nets Demo scalable processing for proxies Demo seamless roaming over in-building, wide-area wireless overlays

Revised Project Schedule Measure & Eval Wireless Ovrly Technologies Demo in-building ovrlys & h/os with dynamic b/w alloc Demo wide-area ovrlys & low latency h/os w/ scalable performance Aug 95 Start Aug 96 Aug 97 Aug 98 End Early Prototype Proxies (1-10 users) Proto Scaled Proxies (100-1000 Users) Scaled Proxies (1000-10000* Users) Large Scale Scalability Demonstrations Initial Architectural Specification Scaled Architectural Specification * on 10 UltraSparc cluster

Milestones to End of Contract 3Q97 Final Architectural Specification Integrated wireless simulation environment based on ns 4Q97 Demonstration of network scaling in simulated WLAN environment Demonstration of network scaling in simulated PR environment 1Q98 Demonstration of scalable, extensible TACC (Transformation, Aggregation, Customization, Caching) Servers 3Q98 Integrated demonstration of wireless networking, real-time conferencing, proxy adaptation, integrated into GloMo “Eye Watering Demo” Participate in July DC Demonstration

What We Proposed to Do Completed In-Progress

What We Proposed to Do Seamless integration of overlay networks Handoff Low latency handoff via user tracking Vertical handoff (power vs. latency) Policy-based VHO (Helen Wang this summer) Transport TCP over high error rate links (snoop) Support services for mobile applications Data type specific compression (proxy distillation) and progressive transmission Dynamic applications partitioning across wireless links (service discovery and adaptation; wingman browser) Integration of multimedia and web applications with wireless environment (vic/vat, browser)

What We Proposed to Do Managing mobile connections to support latency-sensitive applications Link scheduling, class-based queuing Real-time stream adaptation (RTP gateway) Load balancing for scalable mobile processing Network load balancing across overlay networks Network servers to support processing and storage-intensive applications (NOW integration/TranSend) Uniform architecture for applications support (TACC programming model )

Beyond the Proposal Research Infrastructure Asymmetric Transport VINT-based simulation environment Mobile and home IP trace collection Asymmetric Transport TCP enhancements for bandwidth, latency, error asymmetries in PR, wireless cable, DBS subnetworks Satellite Transport Protocol Active Services Architecture RTPGateway’s evolution into MediaGateway Service discovery and adaptation Scalable, Composible Service Architecture TACC model PalmPilot WingMan Browser

Presentation Outline Retreat Purpose and Agenda Project Objectives and Motivation Project Status Review Project Plan and Contributions New Directions Summary and Conclusions

Project Synergies TranSend TACC Model Wireless Access NINJA Scalable, Secure Services Computation in the Network “Smart Spaces” as an app Event-Response Programmable Access BARWAN Wireless Overlay Networks Scalable Proxies RTPGateway Service Discovery vic, vat, wb MASH Collaboration Applications Active Services NOW/Millennium Computing Platform MASH Toolkit Active Services Model

Emerging Distributed System Architecture Spanning Processing and Access Personal Information Management and “Smart Spaces” Distributed Videoconferencing Room-scale Collaboration Speech and Location Aware Applications ICEBERG Computer-Telephony Services MASH Media Processing Services TranSend Extensible Proxy Services Active Services Architecture Distributed Computing Services: Ninja Computing and Communications Platform: Millennium/NOW

Experimental Testbed Smart Spaces Personal Information Management Fax IBM WorkPad Image/OCR Text Speech MC-16 Ericsson CF788 Motorola Pagewriter 2000 WLAN 306 Soda 405 Soda Pager Network Infrastructure 326 Soda “Colab” GSM BTS Millennium Cluster Smart Spaces Personal Information Management Millennium Cluster

Presentation Outline Retreat Purpose and Agenda Project Objectives, Motivation, and Approach Project and Testbed Status Technology Developments Review Project Plan New Directions Summary, Lessons Learned, Conclusions

Summary A complete network and application support architecture for access across lossy links from a wide variety of end devices Access is the killer app Seamless connectivity through wireless overlays Adaptivity through proxy services Heterogeneity, asymmetry, adaptation Asymmetric bandwidth in satellites, cable modems, cellular systems: new transport protocol techniques High loss links: achieving high bandwidth utilization through local intelligent retransmission Adapt representations to the quality of the end device and its network connectivity: proxies for audio/video streams and imageful web documents

Lessons Learned Architectural Principles Dynamic Adaptation, Cross-Layer Optimization, Agent-Based Capabilities, Soft-State New ways of thinking of distributed network-aware service architectures, driving towards NINJA Importance of Testbeds to Drive Research Unanticipated challenges and research opportunities in asymmetric access, active services architecture, scalable service deployment Develop prototypes through several generations Fragility of Student-Developed Infrastructure Maintaining the code base when the hardware base changes with each new PC order Is NT development unavoidable?

Conclusions A small team of outstanding graduate students can accomplish amazing things in a short period of time Let’s celebrate their success!