Transcript Towards Wireless Overlay Network Architectures

The Bay Area Research Wireless
Access Network (BARWAN)
Low-tier
New Ideas
• Wireless Overlay Internetworking
–
–
–
–
–
Satellite
Regional Area
High-tier
“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
–
–
–
–
–
Local Area
Wide Area
High Mobility
Low Mobility
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
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
Schedule
Measure &
Eval Wireless
Ovrly Technologies
Aug 95
Start
Demo in-building
ovrlys & h/os with
dynamic b/w alloc
Aug 96
Demo wide-area ovrlys
& low latency h/os w/
subnet load balancing
Aug 97
Early Prototype
Proxies (1-10 users)
Proto Scaled Proxies
(100-1000 Users)
Initial Architectural
Specification
Scaled Architectural
Specification
Aug 98
End
Scaled Proxies
(1000-10000 Users)
Large Scale
Scalability
Demonstrations
1
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
2
Presentation Outline
•
•
•
•
•
•
Retreat Purpose and Agenda
Project Objectives, Motivation, Contributions
Project Status and GloMo Demo Participation
Review Project Plan
New Directions
Summary and Conclusions
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
Retreat Goals &
Technology Transfer
People
Project Status
Work in Progress
Prototype Technology
Early Access to Technology
Promising Directions
UC Berkeley Project Team
Industrial Collaborators
Reality Check
Hughes Researchers
Government Sponsors
Feedback
Friends
5
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
6
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)
• Hughes Malibu Research Laboratory
– Son Dao
– Yongguang Zhang
– Dante De Lucia
• 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
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
7
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
8
Retreat Schedule
• Wednesday, June 10:
0800 - 1130
1200 - 1330
1330 - 1430
1430 - 1630
Travel from Berkeley to Granlibbakkan
Lunch
Project Overview and Retrospective, Randy Katz
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)
9
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
10
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.
11
Retreat Schedule
• Friday, June 12:
0730 - 0830
0830 - 1000
1000 - 1030
1030 - 1200
1200 - 1300
1300 -
Breakfast
Six Month Planning Session, Anthony Joseph
Break & Check-out
Sponsor/Friends Feedback Session, Randy Katz
Lunch
Depart Granlibakkan
12
Presentation Outline
•
•
•
•
•
•
Retreat Purpose and Agenda
Project Objectives, Motivation, Contributions
Project Status and GloMo Demo Participation
Review Project Plan
New Directions
Summary and Conclusions
13
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
•
• Three Overarching Strategies:
– Heterogeneous Wireless Networks
– Network Optimization
– Dynamic Adaptation
Easily
– Transparent Access
– Localized Service
•
Securely
– Global Authentication
•
Any Medium
– Multimedia: Audio/Video/Graphics
•
Timely
– Performance
•
Cost Effective
– Heterogeneous Support via Proxies
14
Mobile Applications
“Sessions”
Proxy Agents
Transport
(Asymmetric, Heterogeneous, Lossy Links)
Overlay IP (Mobile IP + Overlays)
Snoop Agent
Link Scheduling
Net Connection
Monitoring;
Net-Appl
Interface;
ELN;
Wireless LAN
Location-Dependent
Services
Daedalus/GloMop Architectural
Components
IP
Wire- DBS
Packet
Less SubRadio
Cable Net
Cellular
Data
ATM
SubNet
Mobile IP
Beacons
15
Daedalus/GloMop Architecture
Foreign
Agent
Local
Proxy Host
GW
G
W
Horizontal
Handoff
Basestations
Server
(Correspondent Host)
G
G W
G W
W
Local
Services
Vertical
Handoff
Proxy Host
IP
Internet
GW
Overlay IP
GW
Wireless Subnets
Home Agent
16
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
17
Problems Solved by
Daedalus/GloMop Archtecture
• Thin Client Support
– Dynamic adaptation of content
– Computational support in the infrastructure for resourcepoor clients
• Scalable Infrastructure Services
– Cluster-based computing
– Scalable, extensible, available
– Layered programming model for new service creation
18
Wireless Overlay Networks
Regional-Area
Theatre of Operations
Metropolitan-Area
Rear Echelons
Campus-Area Packet Relay
Bases, Depots, Ranges
In-Building
Command Centers
Training Centers
19
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
20
Asymmetric & Heterogeneous Access
High Bandwidth
– Command Post
– Disaster Relief
– Remote Clinic
– Organization w/poor
Internet connectivity
Low Bandwidth
Local
Subnet
21
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
22
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
Well Connected
Proxy
Poorly
Connected
23
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
24
$
$
$
Cache control
Scalable Proxy Architecture
To Internet
NOW Cluster
SAN (high speed)
Utility (10baseT)
Coordination bus
html
Front
End
gif
PTM
jpg
Control
Panel
$
Cache partition
...
Datatype-specific distiller
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
26
Key Research Themes
•
•
•
•
Dynamic Adaptation
Cross-Layer Optimization
Agent-Based Processing
Soft State
27
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
28
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
29
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
30
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
31
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
32
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@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
33
Presentation Outline
•
•
•
•
•
•
Retreat Purpose and Agenda
Project Objectives, Motivation, Contributions
Project Status and GloMo Demo Participation
Review Project Plan
New Directions
Summary and Conclusions
34
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%
Early
Early Proof
Proof of
of
Concept
Concept
Implementations
Implementations
Demonstrate Seamless
Roaming over
Local and Wide Area
NOWs
Local & Wide-Area
Wireless Overlays
Enhanced E2E Performance
Establishment of
of
Establishment
BARWAN Testbed
Testbed
BARWAN
100%
Measure Alternative
Overlay Network
Performance
Extend with
Emerging
Technologies
35
BARWAN Testbed
DirecPC DBS
(1 mbps)
Vertical
Hand-Off
LOS Wireless Cable
(6 mbps)
DARTNet II
CAIRN
10-30 kbps
Metricom
Cellular Modem
Cellular Packet Data
Packet Radio
Plus local area
RF and IR nets
in Soda Hall
36
Military JTF Application-Oriented
Demonstration: July 98
DBS
Uplink
Reachback
LEO
Forward Area 2
Forward Area 1
Rear
Area
BDE
BN
RDMP Receive
Metachannel Client
Geofiltering
GeoEmail
FreeBSD
Bengal DB
Win 95
RDMP Send
Metachannel Server
Georouting Sender
GeoEmail
Image Server
FreeBSD
ASAMA
Net
ASAMA
Hub
RDMP Receive
Metachannel Client
Geofiltering
GeoEmail
FreeBSD
Uplink
SAMA
Reacback Net
(LEO)
SAMA Control
VXWorks
Video GW
BSDi
LEO
Emulator
FreeBSD
RDMP Receive
Metachannel Client
Geofiltering
GeoEmail
FreeBSD
Bengal DB
Win 95
DBS
Emulator
FreeBSD
BN
BDE
Bengal DB
Win 95
RDMP Receive
Metachannel Client
Geofiltering
GeoEmail
FreeBSD
Bengal DB
Win 95
Soldier
Phone
Net
Bengal DB
Win 95
37
XX
Bengal DB
DBGlomo
Win 95
1
NTSC
Audio
X
XXXX
JTF
1
DBS Emulator
1
ARFOR
RDMP Send
Metachannel server
Resource scheduler
MASH
Georouting sender
Image server
Web server
Video
Gateway
SAMA Control
(LEO Emulator)
FreeBSD
FreeBSD
10Base T
Hub
10 Base T
Hub
10 Base T
Hub
A
FreeBSD
V
MASH
Geonode/Geohost
XGloMo
BSDi
VXWorks
Local RDMP
RDMP Proxy
Metachannel client
Web browser
Video Gateway
(H.261-H.261)
SAMA Hub
915 MHz
(12 kbps/ch
Reachback
Win 95
SAMA Tx
Bengal DB
DB GloMo
Soldier
Radio
Geolocation 1
1st BN Net
1
Soldier
Radio
Soldier
Radio
Downlink To 2nd BDE
1
Bengal DB
DB GloMo
10 Base T
Win 95
10 Base T
FreeBSD
A
V
Geolocation 2
Local RDMP
Metachannel client
Web browser
MASH
Geonode
XGloMo
38
Downlink From 1st Division
X
2
1
MARFOR
Bengal DB
DB GloMo
Win 95
SAMA Tx
FreeBSD
Local RDMP
RDMP Proxy
Metachannel client
Web browser
A
V
MASH
Geonode/Geohost
XGloMo
10 Base T
Hub
Video Gateway
(H.261-H.261)
2
2
Bengal DB
DB GloMo
Win 95
ASAMA Control and
ALOHA Multi-sensor
Simulation
Win 95
ASAMA Rx
(PCI card)
CW Jammer
2nd BN Net
915 MHz
(4 kbps/ch)
ASAMA Tx
(PCI card)
A
FreeBSD
V
ASAMA Tx
(PCI card)
Local RDMP
Metachannel client
Web browser
MASH
Geonode/Geohost
XGloMo
Geolocation 3
39
Military RDF Application-Oriented Demonstration:
July 98
CO
BN
BN
DirecPC
Wireless ATM
CO
CO
Disconnected Operations
Original affiliation
New Affiliation
CO
Browser
GeoFilter
GeoEmail
FreeBSD
Coda Server
FreeBSD
Snoop
BSDi
DirecPC
BSDi
DirecPC
RDRN
ATM Net
MMWN
Net
Special
Gateway
Security
Solaris
Browser
GeoFilter
GeoEmail
FreeBSD
Wings Net
W
Security
Solaris
Coda Client
FreeBSD
Edge
Node
Linux
Edge
Node
Linux
Special
Gateway
Coda Server
FreeBSD
W
Geofilter
GeoEmail
Linux
Web Proxy
GeoFilter
GeoEmail
Linux
Security
Solaris
W
W
W
Coda Client
Browser
GeoFilter
GeoEmail
FreeBSD
W
Security
Solaris
Wings Net
W
W
Geofilter
GeoEmail
Linux
W
Coda Client
Browser
GeoFilter
GeoEmail
FreeBSD
W
Wings Net
W
Security
Solaris
Geofilter
GeoEmail
Linux
W
Coda Client
Browser
GeoFilter
GeoEmail
FreeBSD
40
Presentation Outline
•
•
•
•
•
•
Retreat Purpose and Agenda
Project Objectives, Motivation, Contributions
Project Status and GloMo Demo Participation
Review Project Plan
New Directions
Summary and Conclusions
41
Six Month Plan (to June 98)
• Documentation
• Link Layer
 “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
– 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 lossrecovery mechanisms for Ricochet
 STP implementation released
42
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 (inprogress)
 Extend co-lab testbed (RVic,
Camera control)
• Proxy/Application Support
– Complete MediaBoard (inprogress; 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)
43
Original Research Plan
Year 1
Year 2
Year 3
T1: Overlay Inter network
Management Ser vices
M easure & Eval Ovly Nets Design f or Wide-Area Ovly Demo Wide-Area Ovly
Design f or In-Building Ovly Demo In-Building Ovl y Net Demo Scaled Net Perfor
T2: Mobile Application
Support Services
Design API & App lToolkit Demo API for In-Building
Integrate with NOW Servers
Develop Simple Colla b App s Demo Scaled App s Perf
O1: Wide-Area Deployment
and Demonstr ation
Acceler ate Design f or Wide- Demo Wide-Area Overla y
Area Ovly Integration
Design f or M ultiple Ovly s
O2: Pilot Application
Demonstr ations
Large Scale Demo of Na v
Deploy In-Build Net@UCSF Design Libr Na v & M ed
Eval M ed Image App s Reqs Image Distr App s using API & M ed Image Distr App s
9/95 - 8/96
9/96 - 8/97
Demo Extension to M ultip le
Wide-Area Overla ys
9/97 - 8/98
44
DARPA GloMo Program Goals
DARPA GloMo
FY 96
Daedalus/BARWAN Program
Adaptive Mobile Internet Services
Measure/eval overlay networking tech
Design overlay network architecture
Design proxy architecture, API, toolkit
Prototype proxies for image, video, maps
Location Transparent Computing
FY 97
Demo B/W Adaptive MM Node
Design Scalable Proxies/Proxy Trans Mgr
Arch for “Remote Collaboration by Proxy”
Demo Advanced Mobile Networking Overlay IP and Vertical Handoff
Reliable transport for hetero/asym nets
FY 98
Demo Multimedia Conferencing
Demo Continuous Mobility
Demo scalable processing for proxies
Demo seamless roaming over in-building,
wide-area wireless overlays
45
Revised Project Schedule
Measure &
Eval Wireless
Ovrly Technologies
Aug 95
Start
Demo in-building
ovrlys & h/os with
dynamic b/w alloc
Aug 96
Demo wide-area ovrlys
& low latency h/os w/
scalable performance
Aug 97
Early Prototype
Proxies (1-10 users)
Proto Scaled Proxies
(100-1000 Users)
Initial Architectural
Specification
Scaled Architectural
Specification
Aug 98
End
Scaled Proxies
(1000-10000* Users)
Large Scale
Scalability
Demonstrations
* on 10 UltraSparc cluster
46
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
47
What We Proposed to Do
Completed
In-Progress
48
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)
49
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 storageintensive applications (NOW integration/TranSend)
– Uniform architecture for applications support (TACC
programming model )
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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
– RTPGateway’s evolution into MediaGateway
– Service discovery and adaptation
• Scalable, Composible Service Architecture
– TACC model
– PalmPilot WingMan Browser
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Presentation Outline
•
•
•
•
•
•
Retreat Purpose and Agenda
Project Objectives and Motivation
Project Status
Review Project Plan and Contributions
New Directions
Summary and Conclusions
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Project Synergies
BARWAN
Wireless Overlay Networks
Scalable Proxies
vic, vat,
wb
TranSend
TACC Model
Wireless Access
NINJA
Scalable, Secure Services
Computation in the Network
“Smart Spaces” as an app
Event-Response
Programmable Access
RTPGateway
Service Discovery
MASH
Collaboration Applications
Active Services
MASH Toolkit
Active Services
Model
NOW/Millennium
Computing Platform
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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
Active Services Architecture
TranSend Extensible
Proxy Services
Distributed Computing Services: Ninja
Computing and Communications Platform: Millennium/NOW
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Experimental Testbed
Fax
IBM
WorkPad
Image/OCR
Text
Speech
MC-16
Ericsson
CF788
306 Soda
Motorola
Pagewriter 2000
WLAN
405 Soda
326 Soda “Colab”
Pager
GSM BTS
Network
Infrastructure
Millennium Cluster
Smart Spaces
Personal Information Management
Millennium Cluster
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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
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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
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Lessons Learned
• Architectural Principles
– Dynamic Adaptation, Cross-Layer Optimization, AgentBased 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?
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Conclusions
• A small team of outstanding graduate
students can accomplish amazing things in a
short period of time
• Let’s celebrate their success!
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