Making a Case for UCLP in a Dynamic World

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Making a Case for UCLP in a Dynamic World
Jorg LiebeherrUniversity of Torontojorg_at_comm.ut
oronto.ca
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Dynamic Information Management in UCLP

• Goal Support dynamic information management in
  UCLP
• Dynamic information requirements
• unknown, uncertain and changing resource
  requirements
• involving multiple administrative domains
• with unpredictable or unreliable connectivity
• with temporal or geographical bounds on
  information availability and validity
• with situation-based improvising
• HyperCast could be an enabling technology for
  dynamic information management in UCLP networks

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Dynamic Information Management in UCLP

• HyperCast has the potential to enhance present
  UCLP capabilities
• Scalability in users and resources
• Decoupling of users and resources
• Multiple domains without central repository
• Security (confidentiality, integrity)
• Short-lived (ephemeral) application scenarios
• Monitor and control
• Extensions to wireless and ad-hoc networks

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HyperCast Project (www.hypercast.org)

• HyperCast is a set of protocols for large-scale
  self-organizing overlay networks

• Main Features
• Open source (LGPL) license
• 100,000 lines of Java
• Socket inspired APIs
• Demonstrated Scalability
• Security protocols
• Monitor and control system
• Field-tested applications
• Emergency response system
• Defense scenarios (area protection)

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HyperCast Peer Networks

• Applications self-organize to form a given
  overlay topology
• Data is forwarded along the edges of the overlay
  topology

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Overlay Socket

• Socket-based API
• Supports different semantics for transport of
  data
• Supports different overlay topologies
• Supports different protocols in substrate network
  (UDP unicast, UDP multicast, TCP, or SSH tunnels)
• Heavy use of XML

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HyperCast overlay sockets

• In HyperCast, each overlay node is represented by
  an overlay socket
• Application programs create overlay sockets, and
  send/receive data through the socket
• Each overlay socket has two connections to the
  substrate
• Control Establish and maintain the topology
• Data Exchange application data
• A overlay network is a collection of overlay
  sockets

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Data exchange

• Several data exchanges are supported
• One-to-One (Unicast)
• One-to-All (Multicast)
• Many-to-One (Incast)

• Delivery Semantics
• Best-effort
• In-order
• Reliable

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Writing Programs with Overlay Sockets

• Application Programming Interface (API) stays
  close to Berkeley Socket API
• Programs are independent of overlay topology and
  substrate network

//Generate the configuration object
OverlaySocketConfig ConfObj
OverlaySocketConfig.createOLConfig("hypercast.xml
") //Create an overlay socket I_OverlaySocket
socketConfObj.createOverlaySocket(null) //Join
an overlay socket.joinOverlay() //Create a
message OL_Message msg socket.createMessage(byt
e data) //Send the message to all members in
overlay network socket.sendToAll(msg)
//Receive a message from the socket OL_Message
msg socket.receive() //Extract the payload
byte data msg.getPayload()
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Experiment Scalability
Platform Cluster of 100 PCs Measurement How
long does it take to add M members to an overlay
network of N members ?
Time to Complete (sec)
MN members
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Hypercast Application Video-streaming in ad-hoc
network
(built in 2004)
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Snapshot
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HyperCast Application Area Protection

• Sensor Nodes
• Passive IR, Seismic, and Magnetic sensors
  attached to Xbow MicaZ mote
• Gateways
• XBow Stargate with MicaZ mote, NovaRoam radio,
  and USB web cam
• Acting as image capture, sensor fusion, and
  network integration point
• Robot
• Foster Miller Talon equipped with 4 infrared
  cameras and a zoom camera
• Attached laptop with GPS receiver and web camera

Network Technologies Zigbee, NovaRoam, and
802.11b
Application built as part of a US Army project on
networking unattended ground sensors (PIs B.
Horowitz, J. Liebeherr, S. Patek)
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Scenario
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Mobile Ad-Hoc
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Wireless Ad-hoc Testbed

• HP iPAQ 5555 PDA (x 8)
• 400MHz Intel XScale CPU, 128MB
• Jeode JVM
• Built-in 802.11b
• Toshiba M200 Tablet PC (used as monitor)
• 1.5GHz Intel Centrino CPU, 512MB
• Built-in 802.11g
• HyperCast overlay software

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Performance of Overlay in Ad hoc network

• Multi-hop
• Six iPAQ PDAs in a line topology
• Distance between PDAs is 30, 60, 90 ft
• Outdoor measurement (taken over several days)
• 10,000 messages (_at_ 512 byte)
• TCP adapter
• Fixed topology

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Security
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Security Mechanisms

• Authentication with X.509 certificates
• Certificates are exchanged before any other
  communication takes place
• Support for confidentiality and integrity using
  one of three methods
• SSL (Secure Socket Layer)
• Shared Keys
• All nodes share a common key
• Neighborhood Keys
• Each node has a secret that it shares only with
  its neighbors

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Encrypting a Message
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Forwarding an Encrypted Message
Message
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Encrypted Payload (with Neighborhood Keys)
sender
1
2
5
6
receiver
4
3
Data plot removed because of size.

• Throughput 4.221 Mbps

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Monitor and control
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Monitor and Control System

• Loosely modeled after SNMP
• Each application component collects statistics
• Statistics can be accessed by a remote monitor
• XML oriented
• Statistics are internally stored as XML documents
• Format of statistics is described in XML schemas
• Transmitted messages have XML format
• Dynamically created content
• Schemas for statistics are created dynamically
  upon receiving a query
• Applications can add statistics dynamically

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Monitor Overlay Network
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Hierarchy of statistics
ltSocketgt ltNodegt . ltNodeAdaptergt .
ltUBytesSentgt 1004 lt/UBytesSent
gt lt/NodeAdaptergt lt/Nodegt ltConfiggt .
lt/Config gt ltRecvBufgt . lt/RecvBufgt ltSocketAdapte
rgt . lt/SocketAdaptergt lt/Socketgt
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Accessing Statistics

• Statistics are accessed using XPath expressions
• Adressing the number of bytes sent
• /Socket/Node/NodeAdapter/UBytesSent
• Addressing all statistics of the overlay node
• /Socket/Node

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GUI for monitoring an Overlay Network
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GUI for monitoring an Overlay Network
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HyperCast and UCLP
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Information Management with Peer Networks

• Concept
• Each resource or user can be a member of
  arbitrarily many peer networks
• Access to information is provided through
  dynamically created peer networks

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UCLP w/HyperCast Flexible resource allocation
user
user
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UCLP w/HyperCast Hierarchical Structure of UCLP
Services
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UCLP w/HyperCast Sharing of resources
user
user
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UCLP w/HyperCast Security
user
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UCLP w/HyperCast Monitor and Control of
resources
user
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Conclusions

• HyperCast is software for self-organizing peer
  networks
• Overlay socket is a programming interface for
  overlay networks
• Independent of type of peer network
• Independent of type of substrate network
• HyperCast appears suitable to support UCLP in
  scenarios that are
• highly dynamic
• highly diverse
• highly complex
• Suitability of HyperCast peer networks in complex
  information management scenarios is established
• HyperCast web site http//hypercast.org
• Design documents, download software, user
  manualRelease of Java implementation under
  Library GNU license.