Broadband and Wireless Networking Laboratory

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Broadband and Wireless Networking
Laboratory School of Electrical and Computer
Engineering Georgia Institute of Technology,
Atlanta, GA, USA
NASA Goddard Space Flight Center Greenbelt, MD,
20771, USA
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IP QoS NETWORK PROJECT(NASA Goddard, Raytheon,
Swayles)

• Challenges
• Differentiated Services
• End-to-End QoS
• Integrated Services for Multimedia
• Network Management

NASA Ames Research Center
NASA Goddard Space Flight Center
BWN Laboratory GATECH
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• BWN-Lab Physical Testbed
• Experiments and Issues

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BWN-Lab TESTBED
7204 VXR
ATM155 Mbps
Gigabit Ethernet
Fast Ethernet
ATM 622 Mbps
7505
Lightstream 1010
Catalyst 6506
Catalyst4000
7204 VXR
ExternalLightstream
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TESTBED HARDWARE

• 2 Cisco 7200 routers
• FastEthernet/OC3/GigabitEthernet interfaces
• Cisco 7500 router
• GEIP/OC12 interfaces
• Cisco Catalyst 6506 layer 3 switch
• GEIP interface
• Cisco Catalyst 4000 switch
• FastEthernet ports
• Cisco LightStream 1010 switch
• OC3 interfaces

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TESTBED SOFTWARE

• Cisco IOS
• Version 12.2(1)E1 on the routers
• Native IOS on switch 6500
• End-hosts
• MS Win ME and Linux RedHat 7.2
• ALTQ 2.2 Scheduling/Queueing Software
• Iperf traffic generation and traffic
  characteristic measurement
• MRTG and MRTG (modified MRTG for 10s sampling)

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DiffServ TESTBED NETWORK TOPOLOGY
DS domain
NASA
Abilene
marking policing
scheduling
DS domain
marking
shaping
BWN-Lab
DS domain
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DiffServ EXPERIMENTS

• EDGE COMPONENTS
• Classification/Marking Policy Based Routing
  (PBR) allows classifications based on IP
  Precedence.
• Policing Committed Access Rate (CAR) enforces a
  specified traffic profile preventing
  non-conformant traffic from entering the network.
  
• Shaping Generic Traffic Shaping (GTS) follows
  the token bucket algorithm.
• CORE COMPONENTS
• Queueing Class-Based WFQ (CBWFQ) regulates
  traffic submitted to the network, which may delay
  packets to adjust traffic stream characteristics
  to a defined profile.
• Congestion avoidance Weighted RED (WRED) allows
  definition of multiple drop probability profiles.

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DiffServ EXPERIMENTSSCHEDULING WITH CBWFQ

• We validated CAR and CBWFQ as the policing and
  scheduling mechanisms for DiffServ implementation

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MPLS TESTBED NETWORK TOPOLOGY
Abilene
rtr3
7505
Gigabit
FastEthernet
rtr1
rtr2
7200
7200
Gigabit
Gigabit




LAN 2
LAN 1
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MPLS TE EXPERIMENTS

• Goal Evaluate the benefits of MPLS TE
• Case Study 1 Traditional IP Network (Min Hop ?
  rtr1-rtr2)
• Best-effort service only
• Two 40 Mbps UDP flows are sent from rtr1 to rtr2
• Two 100 Mbps TCP flows are sent from rtr1 to rtr2
• All flows take the min-hop path (FastEthernet)
  and are limited to a total of 100 Mbps. UDP
  starves the TCP flows.

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MPLS TE EXPERIMENTS

• Goal Evaluate the MPLS TE Properties
• Case Study 2 MPLS Network Mixed Flows
• 3 MPLS tunnels were set up.
• Two 40 Mbps UDP flows sent from rtr1 to rtr2
• Two 100 Mbps TCP flows sent from rtr1 to rtr2
• Tunnel1 UDP1 TCP1 Tunnel2 TCP2 Tunnel3
  UDP2
• TCP1 reduces rate when UDP1 arrives due to BW
  contention

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MPLS TE EXPERIMENTS

• Goal Evaluate the MPLS TE properties
• Case Study 3 MPLS Network Separate Flows
• 3 MPLS tunnels
• Two 40Mbps UDP flows sent from rtr1 to rtr2
• Two 100 Mbps TCP flows sent from rtr1 to rtr2
• Tunnel1 TCP1 Tunnel2 TCP2 Tunnel3 UDP1
  UDP2
• No interference between TCP and UDP

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EXPERIMENTAL CONCLUSIONS

• The MPLS TE provides better resource utilization
  and throughput
• Ciscos MPLS tunnels implementation does not
  enforce the limit on the tunnel reserved
  bandwidth needs improvement
• CAR policing is not implementable on Tunnel
  interfaces

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DiffServ-AWARE TEPREEMPTION EXPERIMENTS

• Goal To evaluate Ciscos preemption policy
• 3 MPLS tunnels were setup between routers,
  sharing a FastEthernet link
• Tunnels 1, 2, and 3 together require the total
  link bandwidth
• A new bandwidth request arrives for Tunnel 4,
  which has higher priority than the other 3
  tunnels
• One of the previously established tunnels must be
  preempted. Which one?

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DiffServ-AWARE TEPREEMPTION EXPERIMENTS

• Ciscos preemption policy
• Tunnel priority lowest priority (numerically
  higher)
• Tunnel age Tunnel created earliest

Oldest Tunnel
Lowest Priority
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EXPERIMENTAL CONCLUSIONS

• DiffServ-aware TE support in Ciscos IOS is not
  completely deployed
• Preemption is purely based on tunnel priority and
  age waste of resources

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• TEAM/AA Architecture
• Managing Multiple Domain DiffServ MPLS Networks
• Research Contributions and Issues

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RELATED WORK

• RATES (Routing and Traffic Engineering Server)
• Software by Bell Labs for MPLS Traffic
  Engineering (TE)
• Uses Common Open Policy Service (COPS) and
  Minimum Interference Routing Algorithm (MIRA)
• It achieves TE by routing of bandwidth guaranteed
  LSPs
• TEQUILA (TE for QoS in the Internet at Large
  Scale)
• European research project for end-to-end QoS in
  DiffServ network
• Components for monitoring, TE, SLS management,
  and policy management
• Algorithms and techniques are not concretely
  defined yet and their quantitative evaluation has
  not been carried out
• MATE (Multipath Adaptive Traffic Engineering)
• Software by Bell Labs for MPLS TE
• Assumes LSP layout using a long term traffic
  matrix. The focus is on load balancing short term
  traffic fluctuations
• Not designed for bandwidth guaranteed services

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TRAFFIC ENGINEERING AUTOMATED MANAGER
(TEAM)Design and Management Tools for an MPLS
Domain QoS Manager, to appear in Proceedings of
SPIE ITCOM 2002, Boston, August 2002.
Intra-domain operation
To Neighboring TEAM
To Neighboring Domain
Management Plane
Route
LSP Routing
DiffServ/MPLS Domain
Traffic Routing
LSP Setup/ Dimensioning
Resource
LSP Capacity Allocation
LSP Preemption
Location Management
Mobility
Handoff Management
Network Planning
TEAM
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TEAM/AAARCHITECTURE
Inter-domain operation
TEAM
TEAM
TEAM
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TEAM/AA ARCHITECTURE

• Traffic Engineering Automated Manager (TEAM) and
  Adaptive Agent (AA)
• Manage heterogeneous networks
• Different services such as best-effort,
  real-time, etc.
• Different network technologies such as wired and
  wireless mobile networks
• Manage large networks
• Multiple domains

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TEAM COMPONENTS

• Traffic Engineering Tool 5
• Resource Management
• Optimal Policy for LSP Setup 1, 2
• Adaptive preemption policy for LSPs 3
• Traffic estimation and resource allocation scheme
  4,6

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RESOURCE MANAGEMENT LSP SETUPA New
Threshold-Based Policy for Label Switched Path
Setup in MPLS Networks, in proceedings of ITC
2001, Salvador da Bahia, Brazil, pp. 1-11,
December 2001.Optimal Policy for Label Switched
Path Setup in MPLS Networks, accepted for
publication in Computer Networks Journal, 2002.
Determine an Adaptive Traffic Driven Policy for
LSP Setup and Dimensioning for each MPLS Network.

• Based on Markov Decision Process theory.
• Objective Function
• Minimize the expected infinite-horizon discounted
  total cost.
• To determine the optimal policy, ? the
  transition probabilities and the optimality
  equations
• The optimality equations are solved using the
  Value Iteration Algorithm.

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OPTIMIZATION PROBLEM
Optimal policy ? such that
Optimality equation
where
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TEAM COMPONENTS

• Traffic Engineering Tool 5
• Resource Management
• Optimal Policy for LSP Setup 1, 2
• Adaptive Preemption Policy for LSPs 3
• Traffic estimation and resource allocation scheme
  4,6

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RESOURCE MANAGEMENT LSP PREEMPTIONA New
Preemption Policy for DiffServ-Aware Traffic
Engineering to Minimize Rerouting, to appear in
Proceedings of IEEE INFOCOM 2002, New York City,
June 2002.

• Non-real time applications may afford to have
  their transmission rate reduced.
• By reducing the rate in a fair fashion
• These LSPs would not be torn down,
• There would be no service disruption, extra setup
  and tear down signaling
• THERE WOULD BE NO REROUTING DECISIONS

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ADAPTIVE PREEMPTION POLICY (Contd.)

• Combines the three main preemption criteria
• Priority of preempted LSPs
• Number of preempted LSPs
• Bandwidth of preempted LSPs
• Optimization formulation and heuristic

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ADAPTIVE PREEMPTION POLICY OPTIMIZATION
FORMULATION

• Minimize
• F ? (priority cost) ? (number of LSPs) ?
  (preempted bandwidth) BW module cost
• Subject to
• Number of preempted modules ? r
• Number of preempted modules in a preempted LSP is
  equal to total number of modules in the LSP.
• Number of preempted modules in a rate reduced LSP
  is less than ? of the total number of modules
  in the LSP.

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PERFORMANCE COMPARISONCOMMERCIAL VERSUS
ADAPTIVE POLICY
Number of Preempted LSPs Bandwidth
Wastage
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TEAM COMPONENTS

• Traffic Engineering Tool 5
• Resource Management
• Optimal Policy for LSP Setup 1, 2
• Adaptive Preemption Policy for LSPs 3
• Traffic Estimation and Resource Allocation Scheme
  4,6

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RESOURCE MANAGEMENT LSP BANDWIDTH ALLOCATION
A method to determine Bandwidth Allocation for
LSPs with less bandwidth wastage and less
re-dimensioning in an MPLS Network.

• Simple method is over-provisioning or cushion
• New Method ? based on Kalman filter for optimal
  estimation of the traffic and capacity prediction
  by determining transition probabilities

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TRAFFIC ENGINEERING AUTOMATED MANAGER
(TEAM)Design and Management Tools for an MPLS
Domain QoS Manager, to appear in Proceedings of
SPIE ITCOM 2002, Boston, August 2002.
Intra-domain operation
To Neighboring TEAM
To Neighboring Domain
Management Plane
Route
LSP Routing
DiffServ/MPLS Domain
Traffic Routing
LSP Setup/ Dimensioning
Resource
LSP Capacity Allocation
LSP Preemption
Location Management
Mobility
Handoff Management
Network Planning
TEAM
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TEAM/AAARCHITECTURE
Inter-domain operation
TEAM
TEAM
TEAM
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PUBLICATIONS

• 1 C. Scoglio, T. Anjali, J. de Oliveira, I.
  Akyildiz, and G. Uhl, A New Threshold-Based
  Policy for Label Switched Path Setup in MPLS
  Networks, in proceedings of ITC 2001, Salvador
  da Bahia, Brazil, pp. 1-11, December 2001.
• 2 T. Anjali, C. Scoglio, J. de Oliveira, I.
  Akyildiz, and G. Uhl, Optimal Policy for Label
  Switched Path Setup in MPLS Networks, accepted
  for publication in Computer Networks Journal,
  2002.
• 3 J. de Oliveira, C. Scoglio, I. Akyildiz, and
  G. Uhl, A New Preemption Policy for
  DiffServ-Aware Traffic Engineering to Minimize
  Rerouting, to appear in proceedings of IEEE
  INFOCOM 2002, New York City, June 2002.
• 4 C. Bruni, C. Scoglio, and S. Vergari,
  Optimal Capacity Provisioning for Label Switched
  Paths in MPLS Networks, to appear in
  proceedings of IFIP-TC6 Networking 2002, Pisa,
  Italy, May 2002.
• 5 J. de Oliveira, C. Scoglio, T. Anjali, L.
  Chen, I. Akyildiz, and G. Uhl, Design and
  Management Tools for an MPLS Domain QoS Manager,
  to appear in Proceedings of SPIE ITCOM 2002,
  Boston, August 2002.

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PUBLICATIONS (Contd.)

• 6 T. Anjali, C. Scoglio, I. Akyildiz, and G.
  Uhl, A New Scheme for Traffic Estimation and
  Resource Allocation for Bandwidth Brokers,
  submitted for publication, 2002.
• 7 T. Anjali, C. Scoglio, L. Chen, I. Akyildiz,
  and G. Uhl, ABEst An Available Bandwidth
  Estimator within an Autonomous System, submitted
  for publication, 2002.
• 8 J. de Oliveira, F. Martinelli, and C.
  Scoglio, SPeCRA A Stochastic Performance
  Comparison Routing Algorithm for LSP Setup in
  MPLS Networks, submitted for publication, 2002.
• 9 J. L. Marzo, E. Calle, C. Scoglio, and T.
  Anjali, Adding QoS Protection in Order to
  Enhance MPLS QoS Routing, submitted for
  publication, 2002.