Challenges in the Next Generation Internet

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Challenges in the Next Generation Internet

• Xin Yuan
• Department of Computer Science
• Florida State University
• xyuan_at_cs.fsu.edu
• http//www.cs.fsu.edu/xyuan

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• Internet Traffic doubles each year.
• Backbone traffic growth Odlyzko01
• 100 per year from 1990 1994.
• 1000 per year in 1995 and 1996.
• 100 per year in 1997 through 2000.
• Internet is becoming more and more ubiquitous.
• More commercial applications.
• More multimedia applications.

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• The Next Generation Internet will meet all these
  challenges
• Large bandwidth through the optical DWDM (Dense
  Wavelength Division Multiplexing) technology.
• multi-service.
• service differentiation (Quality of Service).
• Security
• How to expose the large bandwidth to applications?

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IP over WDM protocol stack
IP
IP
ATM
WDM-aware Electronic layer
SONET
WDM
WDM
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• IP over WDM WDM-aware electronic layer
• Reconfiguration and load balancing.
• Protection and restoration
• Optical switching
• Network management/control
• Cross-layer optimizations

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• IP over WDM Protection and restoration.
• When a link is down, services should not be
  interrupted for too long.
• One optical link supports a large number of
  flows.
• SONET detects failure in 2-100us, restores
  operation in 60 ms.
• Need to extend the SONET model to deal with the
  general mesh networks.
• Determine the backup path together with the main
  path (more complex in routing).
• How to utilize the capacity effectively?

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• IP Quality of Service
• To control the network service response so that
  is is predictable.
• To allow the client to establish in advance the
  service response that will be obtained from the
  network.
• To control the contention for network resources.
• To allow for efficient total utilization of
  network resources.

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• IP Quality of Service models
• Integrated Service (IntServ)
• End to End QoS guarantee (What users want)?
• Too many states for each router to maintained
  (not scalable).
• Cannot be deployed incrementally.
• Differentiated Services (DiffServ)
• Define PHB (per hop behavior).
• Each router distinguishes 64 queues (scalable).
• End-to-end QoS by provisioning?
• Stateless QoS model
• Carrying QoS information at each packet.

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• IP Quality of Service other issues
• Packet scheduling FIFO does not work anymore.
• Fair queuing is quite expensive.
• Routing
• Taking QoS metrics into consideration can make it
  very difficult
• Scalable QoS routing for large networks can be
  hard.

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• Exposing hardware performance to applications.
• Different applications result in different
  traffic patterns.
• Special communication optimizations can be
  performed by considering (1) the communication
  pattern and (2) the underlying network
  architecture.
• Compiled communication for Message Passing
  Interface (MPI) programs over clusters of
  workstations.

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• Compiled Communication
• Traditional communication optimization
• In the compiler
• Reducing the size and volume of communications.
• Architecture independent optimizations.
• In the library
• Architecture dependent optimizations.
• Dont know the sequence of communications in
  applications.
• Compiled communication
• Compiler knows the sequence of communications in
  applications and the network architecture.
• Can perform architecture dependent optimizations
  across communication patterns.

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MPI_Scatterv() MPI_Scatterv()
MPI_Open_Group() MPI_Data_Move() MPI_Close_Group
() .. MPI_Open_Group() MPI_Data_Move() MPI_Clo
se_Group()
MPI_Open_Group() MPI_Data_Move() .. MPI_Data_Mo
ve() MPI_Close_Group()
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• Compiled Communication How to make it happen?
• Traditional communication libraries do not
  support this communication model (easy to use is
  the main goal).
• Compiled communication capable MPI library
• Should allow the compiler (user) to management
  network resources
• In our prototype
• Compiler can manage multicast group.
• Compiler can schedule the communications (for
  collective communications).
• Need a compiler that can do the analysis.