A Survey of Active Network Research

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A Survey of Active Network Research

• ByTennehouse,Smith,Sincoskie,Wettherall,Minden
• Presented ByPrashant, Ravikiran, Ashutosh

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Objective

• Introduction to Active Networks
• - Motivation
• - Aims
• - Impact
• How to Implement Active Network
• - Discrete Approach
• - Integrated Approach
• Snapshot of current research

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Active Network
Active network is an approach to network
architecture in which the nodes of the network
perform customized computations on the message
flowing through them. This concept permit
applications to inject programs into the nodes of
network.
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• Example
• One can load trace program to routers and
  program will be executed then and there when his
  packets are processed at that router(active).

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Origin of Active Networks It is the result of
discussion within Defense Advance Research
Projects Agency(DARPA) research community in
1994-95.
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• Motivation for Active Network
• Difficulty of Integrating new technologies and
  Standards.
• Poor performance because of redundant operations
  at several protocol layers.
• Problems in accommodating new services.

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• Existing Applications
• Many application use a sort of Active Network
  approach to handle current network related
  problems.
• e.g.
• Firewall
• Web Proxies
• Nomadic Routers
• Application Services

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Technology Advancement Recent advances in
programming languages, compiler, and operating
systems provides the safe and efficient execution
of mobile programs.
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• Aim of Active Network
• Programmable nodes.
• Standard execution environment
• No Standard functions

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Impact of Active Networking Accelerating
infrastructure innovation A new technology from
prototype demonstration to large scale
deployment takes about 10 years.Current backlog
are . RSVP . IPv6 . Multicast services But
Active networks eliminate the need for formal
standardization.
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• Enabling new technologies
• Merging and Distribution of information

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N sources sending signals to M destinations. End
nodes does all of its mixing,work With Active
networks, work
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• Stock Quotes
• At present generally web caches do not cache the
  stock quotes because of its dynamic nature and
  even if it caches, the granularity of the
  object(entire web page) is inappropriate.
• Active networks can cache quotes at network nodes
  using a per-stock name granularity.So, all client
  request can be fulfilled with specified degree of
  currency

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• Online Auctions
• Servers responds to the current price requests
  but due to delay in the network the information
  carried by the packet may become outdated when it
  reach the client. Then, the auction server will
  receive bids that are too low and need to be
  rejected and this imposes overhead on the heavily
  busy server.
• With active networks these bids can be filtered
  out before they reach the server. So the response
  time of bid rejection to the client and server
  processing overhead is reduced.

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User Aware Network Protection Active network may
admit the design of integrated mechanism to
govern network resources and information flowing
through them. So, program in Network security
policy for the network on a per-user or per-use
basis is allowed.
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Active Network Management Active technologies
could be used to implement sophisticated
approaches to do network monitoring and
uninteresting event filtering.
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• Rethinking Performance
• Despite increasing the amount of processing at
  nodes, Active network will lead to improved
  performance.
• i.e. Reduced throughput and increasing latency
  appear to degrade the performance, they may
  actually improve performance because of reduce
  demand of bandwidth at endpoints, network
  congestion.
• Network performance is not always positively
  related to the Application performance.

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Caching in the memory as in the stock quote
example can reduce latency of data access when
the server is busy. When network nodes in the
auction application reject low bids, they inform
the losing end nodes than could the overloaded
(and farther away) server.
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• Performance also depends on the location where
  the active node is deployed.
• In the sensor fusion example, the greatest
  decrease in bandwidth utilization occurs when the
  splitting of multicast streams is performed as
  late as possible and mixing as early as possible
• In stock quote example, it is important to place
  the caches where they will serve the large number
  of client request.
• In online auction,filter should be far enough
  from the server to turn back low bids asap, but
  close enough to the server to get proper up-to
  date price.

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Approaches to implement the Active
Network Programmable Switches- A discrete
approach User would first inject their custom
processing routines into the required routers.
Then they would send there packets through such
programmable nodes. When the packet arrives at
the node its header is examined and the
appropriate program is executed.
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Capsules-An Integrated Approach In this approach
program is integrated in the packet along with
the data. When these capsule arrive at the active
nodes then it interprets the program and sends
the embedded data depending on its
interpretation. This is same to the Postscript
code, where actual data is embedded in program
fragments that the printer understands.
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Active IP
Active option is in the payload of the packet,
the legacy router can route the packet
transparently to active node where the ACTIVE
Option code will be evaluated and executed.
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• Common Programming model
• Program EncodingOur objectives of program
  encoding are that they support
• Mobility- transfer programs and to execute them
  on different platforms
• Safety-restrict resources that program can access
• Efficiency-enabling above without compromising
  network performance.

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• Mobility can be achieved at different level of
  program representation.
• Source level- Use of scripting language say TCL.
• Intermediate level- Use of Byte code virtual
  instruction say in JAVA.
• Object level- Use binary formats as in Omniware.

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Common Primitives The services built into each
node might include several categories of
operations primitives that provide access to the
nodes environment (e.g node address, time of day
and so on). Node resources and their
allocation There must be a common model of node
resources like bandwidth, processing capacity and
the means by which policies governing their
allocation are communicated.Safe resource
allocation is a considerable research area.
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• Current research
• The goal of research is to develop
• Languages and compiler for active software.
• Platforms for deploying Active Network nodes.
• Architecture for capsule and programmable
  switches
• Safe resource allocation schemes.

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• Massachusetts Institute of Technology-This team
  is prototyping an architecture based on the
  capsule approach and studying active storage,
  NACK fusion and filtering.Demand loading is also
  a concern.
• University of Pennsylvania-The Switch Ware
  project proposes a switch, which has a
  programmable element performing switching
  function.
• Bell Communication Research- Several aspects of
  the Penn design will be studied jointly with
  Bellcore using different infrastructure OPCV2.

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• Columbia University-Netscript architecture which
  uses encapsulation approach along with scripting
  language is developed.
• Carnegie Mellon University-It is developing
  resource management mechanism in support of
  application aware networks.
• Other Sites-University of Arizona, Georgia
  institute of technology, University of Kansas,
  BBN, University of Cincinnati.