The%20SAHARA%20Four-Layer%20Model;%20Case-studies%20in%20Composition

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The SAHARA Four-Layer ModelCase-studies in
Composition

• Bhaskaran Raman, Jimmy Shih, Randy H. Katz,
• SAHARA, EECS, U.C.Berkeley

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Layered Reference Model for Service Composition
End-User Applications
Applications Services
Application Plane
Middleware Services
End-to-End Network With Desirable Properties
Enhanced Paths
Connectivity Plane
Enhanced Links
IP Network
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Work in Progress

• Enhanced Links
• Congestion Pricing for Access Links
• Auction-based Resource (Bandwidth) Allocation
• Traffic Policing/Verification of Bandwidth
  Allocation

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Congestion Pricing at Access Links

• Setup
• 10 users
• 3 QoS (Slow-going, Moderate, Responsive)differ
  on degree of traffic smoothing
• 24 tokens/day, 15 minutes of usage per charge
• Acceptable
• Users make purchasing decision at most once every
  15 minutes
• Feasible
• Changing prices cause users to select different
  QoS
• Effective
• If entice half of users to choose lower QoS
  during congestion, then reduce burstiness at
  access links by 25

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Auction-based Resource Allocation

• Problem
• Efficiently and effectively allocate resources
  according to applications dynamic requirements
• Approach
• Leveraging auction schemes and work-load
  predictions

• Capabilities
• Bidders can place bids based on application
  requirements and contention level.
• Bidders can place bids for near future resource
  requirements based on recent history.
• Bidders can express both utility and priority to
  auctioneer.
• Auctioneer can dynamically change applications
  priority by changing the token allocation rate.
• Status
• On-going work
• First application bandwidth allocation in ad hoc
  wireless networks

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Mobile Virtual Network OperatorComposition and
Cooperation
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Bandwidth Allocation
R1 attaches new certificate to the refresh message

• Problem scalable (stateless) and robust
  bandwidth allocation
• Control Plane
• Soft state
• Per-router per-period certificates for robustness
  without per-flow state
• Random sampling to prevent duplicate refreshes
• Data Plane
• Monitor aggregate flows
• Recursively split misbehaving aggregates

misbehaving aggregate split it
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Work in Progress

• Enhanced Paths
• BGP Route Flap Dampening
• BGP Policy Agents
• Backup Path Allocation in Overlay Networks
• Host Mobility
• Multicast Interoperation

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BGP Stability vs. Convergence

• Problem
• Stability achieved through flap dampingRFC2439
• Unexpectedflap damping delays convergence!

• Topology clique of routers

• Solution selective flap damping sigcomm02
• Duplicate suppression
• Ignore flaps caused by transient convergence
  instability
• Still contains stability
• Eliminates undesired interaction!

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Policy Management for BGP

• 3-15 minute failover time
• Slow response to congestion
• Unacceptable for Internet service composition

• Lack of distributed route control
• Need distributed policy management
• Explicit route policy negotiation

• Identified current routing behavior
• Inferred AS relationships, topology
• Next gather traffic data, finish code, emulate

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Backup Path Allocation in Overlay Networks

• Challenge
• Disjoint primary and backup path in the overlay
  network may share underlying links because the
  overlay network cannot control underlying links
  used by a path
• Problem
• Find a primary and backup path pair with minimal
  failure probability based on correlated overlay
  link failures
• Approach
• Decouple backup path routing from primary path
  routing
• Route backup paths based on failure probability
  cost which measures the incremental path failure
  probability caused by using a link in the path
• Main Result
• Can be 20-30 more robust compared to shortest
  disjoint path allocation
• Status
• Finished work, submitted to ICNP02

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Host Mobility Using an Internet Indirection
Infrastructure

• The Problem
• Internet hosts increasingly mobileneed to
  remain reachable
• Flows should not be interrupted
• IP address represents unique host ID net
  location
• ROAM (Robust Overlay Architecture for Mobility)
• Leverages i3 overlay network triggers forward
  packets
• Efficiency, robustness, location privacy,
  simultaneous mobility
• No changes to end-host kernel or applications
• Cost i3 infrastructure, and proxies on
  end-hosts
• Simulation Experimental Results
• Stretch lower than MIP-bi ? able to choose nearby
  triggers
• 50-66 of MIP-tri when 5-28 domains deploy i3
  servers
• Even 4 handoffs in 10 seconds have little impact
  on TCP performance

(ID, data)
(ID, R)
Sender (S)
(ID, data)
(ID, R)
Receiver (R)
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Multicast Broadcast Federation

• Goal compose different non-interoperable
  multicast domains to provide an end-to-end
  multicast service.
• Should work for both IP and App-layer protocols.
• Approach overlay of Broadcast Gateways (BGs)
• BGs establish peering between domains.
• Inside a domain, local multicast capability is
  used.
• Clustered gateways for scalability.
• Independent data flows and control flow.

Source
Broadcast Domains
CDN
IP Mul
SSM
Clients
BG
Peering
Data

• Implementation
• Linux/C event-driven program
• Easily customizable interface to local multicast
  capability (700 lines)
• Upto 1 Gbps BG thruput with 6 nodes.
• Upto 2500 sessions with 6 nodes.

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Work in Progress

• Middleware Services
• Measurement and Monitoring Infrastructure
• Robust Service Composition
• Authorization Interworking

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Internet Distance Monitoring Infrastructure

• Problem N end hosts in different administrative
  domains, how to select a subset to be probes, and
  build an overlay distance monitoring service
  without knowing the underlying topology?

• Solution Internet Iso-bar
• Clustering of hosts perceiving similar
  performance
• Good scalability
• Good accuracy stability
• Tested with NLANR
• AMP Keynote data
• Small overhead
• Incrementally deployable
• SIGMETRICS PAPA 02
• CMG journal 02

Cluster C
Cluster B
Cluster A
Monitor
Distance from monitor to its hosts
Distance measurements among monitors
End Host
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Availability in Wide-AreaService Composition
Text to audio

• Issue Multi-provider ? WA composition
• Poor availability of Internet path ? Poor service
  availability for client

Text to audio

• gt15sec outage
• Note BGP recovery could take several minutes
  Labovitz00

• Fix detect and recover from failures using
  service replicas
• Highlight of results
• Quick detection (2sec) possible
• Scalable messaging for recovery (can handle
  simultaneous failure recovery of 1000s of
  clients)
• See SPECTS02 paper
• More recent results on load balancing across
  service replicas

• End-to-end recovery in about 3.6sec 2sec
  detection, 600ms signaling, 1sec state
  restoration

WA setup UCB, Berk. (Cable), SF (DSL), Stan.,
CMU, UCSD, UNSW (Aus), TU-Berlin (Germany)
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Authorization Control Across Administrative
Domains
Trusted third party
Domain 1
Should grant access?
Authorization Authority
Service
Decision
Request - certificates - credentials
Verification
Policy compliance check
Certificates Credentials
Credential transformation
Domain 2
User
Trust peering agreement - credential
transformation rule

• Authorization authority
• Provides authorization decision service.
• Manages different verification methods and
  credentials.
• Trust peering agreement
• Credential transformation rule
• Acceptable verification method

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Work in Progress

• Applications Services
• Voice Over IP
• Adaptive Content Distribution
• (Universal In-Box)

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IP Telephony Gateway Selection
LS
ITG
LS
ITG
LS
ITG

• Results
• Congestion sensitive pricing decreases
  unnecessary call blocking, increases revenue, and
  improves economic efficiency
• Hybrid redirection achieves good QoS and low
  blocking probability

• Goal High quality, economically efficient
  telephony over the Internet
• Questions How to
• Perform call admission control?
• Route calls thru converged net?

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SCAN Scalable Content Access Network

• Problem Provide content distribution to clients
  with small latency, small of replicas and
  efficient update dissemination
• Solution SCAN
• Leverage P2P location services to improve
  scalability and locality
• Simultaneous dynamic replica placement
  app-level multicast tree construction

data plane
data source

• Close to optimal of replicas wrt latency
  guarantee
• Small latency bandwidth for sending updates
• IPTPS 02
• Pervasive 02

Web server
SCAN server
network plane
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Layered Reference Modelfor Service Composition
Composed Service at Layer i
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Evaluation Emulation Testbed

• Idea Use real implementation, emulate the
  wide-area network behavior (NistNET)
• Opportunity Millennium cluster

Rule for 1?2
App
Emulator
Node 1
Rule for 1?3
Lib
Rule for 3?4
Node 2
Rule for 4?3
Node 3
Node 4
Also have limited (8-node) wide-area testbed