Active Networking

1

• Active Networking
• at
• Washington University
• Dan Decasper

2
Overview

• Why do we need an Active Network platform?
• Our software architecture
• An example Congestion control for multicast
  video
• Future work

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What is Active Networking?

• The router does more than plain IP forwarding
• Packets can contain program code which is
  executed as the packet transits through the
  router
• Code can be installed by an administrator at run
  time
• Part of the application runs on the router

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Why Active Networking?

• Network Protocols are hard to deploy
• Application-specific processing on routers can
• Improve the end system application (congestion
  control, reliable multicast)
• Reduce network bandwidth (sensor data mixing)
• End systems might not have enough capacity to
  properly display content (wireless devices)

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Requirements for our AN Platform

• Code should be deployed automatically and
  on-demand to router
• however this happens rarely!
• Simple security model we understand
• Fast enough for data-path applications
• 155 Mbits/s in software
• 1.2 Gbits/s with hardware support (FPGA)

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Router Plugins

• Modular kernel software architecture developed at
  WashU and ETH Zurich
• Allows to
• dynamically add code modules called Plugins at
  run-time into the IP forwarding loop
• bind plugins to individual IP flows
• Provides fast packet classification

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Plugin Identifiers

• Code identified by protocol numbers,
  port numbers or hardware

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Plugin Identifiers

• Abstract view

F

• Plugin Identifier (PI) determines which plugin
  has to be called

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Plugin Invocation based on Plugin IDs

Active Function Dispatcher (AFD)
lookup plugin identifier
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Plugin Invocation based on Plugin IDs

Plugin Management
check policies
User Space Kernel
Plugin Control Unit
Active Function Dispatcher (AFD)
IP Security
Video Congestion Control
U
U
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Downloading a Plugin

• check policies
• locate plugin

Our Router
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Plugin Invocation based on Plugin IDs

Plugin Management
check digital signatures
User Space Kernel
Plugin Control Unit
Active Function Dispatcher (AFD)
IP Security
MPEG Congestion Control
U
U
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Plugin Management
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Congestion Control for Multicast Video

• Problems with streaming multicast video
• Feedback to the sender does not scale
• Buffering does not work well for real-time video
• Codec does not adapt very well
• Problems with layered multicast
• Adapts slowly
• High level of adaptability requires 100
  multicast groups
• Problem with media gateways
• Code must be installed out-of-band

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Our Approach

• Use our active network architecture
• Allows for automatic on-the-fly deployment of
  scaling code to routers
• Allows for scaling at OC-3
• Use a wavelet-based codec (WaveVideo)
• Provides approximately 100 levels of adaptability
• Loss of packets results in smooth degradation
  (e.g. fewer artifacts or wrongly colored blocks
  than MPEG)

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Our Approach (cont)

• Use a WaveVideo scaling plugin
• Talk to packet scheduler to find out about
  bandwidth available
• Drops packets based on the available bandwidth
  and the importance of the individual packet
• Table lookup to determine whether to drop or
  forward packet

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Video Packets
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Test Network
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Results

• 500 ms to download and install plugins
• 22.3 us to scale individual packet
• 45,000 packets can be scaled per second
• 360 Mbit/s throughput (1KB packets)
• 15 dB PSNR active vs non-active

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ANN Hardware

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The End

• Thank you!!!