Towards%20Wireless%20Overlay%20Network%20Architectures

1
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
R. H. Katz E. A. Brewer, UC Berkeley Subcontract
or 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 34 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
2
The Bay Area Research Wireless Access
NetworkTowards a Wireless Overlay
Internetworking Architecture
Satellite
Regional Area
Low-tier
High-tier
Local Area
Wide Area
Low Mobility
High 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

3
Presentation Outline

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

4
Presentation Outline

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

5
Retreat Goals Technology Transfer
People Project Status Work in Progress Prototype
Technology
Early Access to Technology Promising Directions
Reality Check Feedback
6
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

7
BARWAN/Hughes Team

• Networking
• 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
8
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

9
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)

10
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

11
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.
12
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

13
Presentation Outline

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

14
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

• Three Overarching Strategies
• Heterogeneous Wireless Networks
• Network Optimization
• Dynamic Adaptation

• 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

15
Daedalus/GloMop Architectural Components
Mobile Applications
Proxy Agents
Location-Dependent Services
Transport (Asymmetric, Heterogeneous, Lossy Links)
Sessions
Snoop Agent
Link Scheduling
16
Daedalus/GloMop Architecture
17
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

18
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

19
Wireless Overlay Networks
Theatre of Operations
Rear Echelons
Bases, Depots, Ranges
Command Centers Training Centers
20
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

21
Asymmetric Heterogeneous Access
High Bandwidth
Command Post Disaster Relief  Remote
Clinic  Organization w/poor Internet
connectivity
Local Subnet
Low Bandwidth
22
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

23
Client-PROXY-Server Architecture

• Proxy
• 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

24
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

25
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
26
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

27
Key Research Themes

• Dynamic Adaptation
• Cross-Layer Optimization
• Agent-Based Processing
• Soft State

28
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

29
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

30
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

31
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
  TCPs 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

32
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

33
Technology Transfer

• Proxy Software
• 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_at_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

34
Presentation Outline

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

35
Project Plan and Status
90
Project Start 15 Aug 95 (Start 34 Months)
Scalability
100
Demonstrate via Simulation Ability to Scale to
Large Communities of Mobile Users
Functionality
100
Demonstrate Seamless Roaming over Local and Wide
Area
Early Proof of Concept Implementations
NOWs Local Wide-Area Wireless Overlays Enhanced
E2E Performance
Establishment of BARWAN Testbed
Measure Alternative Overlay Network Performance
Extend with Emerging Technologies
100
36
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
37
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 GeoEm
ail FreeBSD
RDMP Receive Metachannel Client Geofiltering GeoEm
ail 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 GeoEm
ail FreeBSD
RDMP Receive Metachannel Client Geofiltering GeoEm
ail FreeBSD
Uplink
Bengal DB Win 95
Bengal DB Win 95
Video GW BSDi
SAMA Control VXWorks
LEO Emulator FreeBSD
38
Bengal DB DBGlomo
Audio
NTSC
DBS Emulator
FreeBSD
RDMP Send Metachannel server Resource
scheduler MASH Georouting sender Image server Web
server
FreeBSD
Local RDMP RDMP Proxy Metachannel client Web
browser MASH Geonode/Geohost XGloMo Video
Gateway (H.261-H.261)
10 Base T Hub
10Base T Hub
A
10 Base T Hub
V
Video Gateway
915 MHz (12 kbps/ch Reachback
SAMA Hub
SAMA Control (LEO Emulator)
Bengal DB DB GloMo
Geolocation 1
1st BN Net
Bengal DB DB GloMo
10 Base T
Local RDMP Metachannel client Web
browser MASH Geonode XGloMo
10 Base T
Downlink To 2nd BDE
Geolocation 2
39
Downlink From 1st Division
Bengal DB DB GloMo
SAMA Tx
Local RDMP RDMP Proxy Metachannel client Web
browser MASH Geonode/Geohost XGloMo Video
Gateway (H.261-H.261)
A
V
10 Base T Hub
Bengal DB DB GloMo
2nd BN Net
ASAMA Control and ALOHA Multi-sensor Simulation
ASAMA Rx (PCI card)
Local RDMP Metachannel client Web
browser MASH Geonode/Geohost XGloMo
915 MHz (4 kbps/ch)
A
V

CW Jammer
Geolocation 3
40
Military RDF Application-Oriented
DemonstrationJuly 98
CO
BN
BN
Wireless ATM
CO
CO
Disconnected Operations
Original affiliation
New Affiliation
CO
DirecPC BSDi
Browser GeoFilter GeoEmail FreeBSD
Coda Server FreeBSD
Coda Client FreeBSD
Coda Server FreeBSD
Snoop BSDi
Edge Node Linux
Edge Node Linux
Special Gateway
RDRN ATM Net
MMWN Net
Web Proxy GeoFilter GeoEmail Linux
Security Solaris
Special Gateway
Security Solaris
Browser GeoFilter GeoEmail FreeBSD
Wings Net
Wings Net
Wings Net
Coda Client Browser GeoFilter GeoEmail FreeBSD
Coda Client Browser GeoFilter GeoEmail FreeBSD
Coda Client Browser GeoFilter GeoEmail FreeBSD
Geofilter GeoEmail Linux
Security Solaris
Geofilter GeoEmail Linux
Geofilter GeoEmail Linux
Security Solaris
Security Solaris
41
Presentation Outline

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

42
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

43
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)

44
Original Research Plan
9/95 - 8/96
9/96 - 8/97
9/97 - 8/98
45
DARPA GloMo Program Goals
DARPA GloMo 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
46
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
47
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

48
What We Proposed to Do
Completed
In-Progress
49
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)

50
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 )

51
Beyond the Proposal

• Research Infrastructure
• 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
• RTPGateways evolution into MediaGateway
• Service discovery and adaptation
• Scalable, Composible Service Architecture
• TACC model
• PalmPilot WingMan Browser

52
Presentation Outline

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

53
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
54
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
55
Experimental Testbed
Fax
IBM WorkPad
Image/OCR
Text
Speech
MC-16
Ericsson
CF788
Motorola Pagewriter 2000
WLAN
Pager
306 Soda
405 Soda
326 Soda Colab
GSM BTS
Millennium Cluster
Smart Spaces Personal Information Management
Millennium Cluster
56
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

57
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

58
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?

59
Conclusions

• A small team of outstanding graduate students can
  accomplish amazing things in a short period of
  time
• Lets celebrate their success!