Active Networks

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Active Networks The Network Future
By Samatha Gangapuram Prashant Shanti Kumar
Harish Kumar Maringanti
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Assigned Unenviable task

• What
• Why
• How
• Where

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Active Networks What ?

• No general agreement beyond buzz phrases.

Active networks explore the idea of allowing
routing elements to be extensively programmed by
the packets passing through them.
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Legacy Vs Active

• Active Networks
• Active Packet.
• General agreement on model of computation.
• Functionality in each packet.
• Improved resilience to change.

• Legacy Networks
• Passive packet.
• Rely on agreement about protocols.
• Functionality built into each router.
• Change is a long and wrenching process.

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AN - Services
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Active Networks Why ?

• Rapid deployment and development.
• Creating and Tailoring network services.
• Better performance.
• Open to deploy and administer.

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Active Networks How ?

• AN Paradigms
• Programmable Switch Model
• Capsule Model
• Ad hoc Model

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Active Networks How ?

• Programmable Switch

• Code is first transferred to the nodes, out of
  band.
• Packets are treated as data or input to the code.

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Active Networks How ?

• Capsule Model

• Each packet is a program.
• Each intermediate node executes the packet.

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Active Networks How ?

• Ad hoc Model

• Packet contains flags.
• Node contains in-built routines.
• Based on flag, routines are executed.

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A N - Terminologies

• User Application (UA)
• Active Application (AA)
• Execution Environment (EE)
• Node Operating System (NodeOS)

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NodeOS

• The NodeOS is the base layer of any AN
  architecture.
• It manages the resources of the active node and
  co-ordinates the resource demands.
• NodeOS is also responsible for the enforcement of
  security policies.
• Examples
• SANE OS, JANOS, SCOUT, ExoKernel

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E E

• Nerve Center of the Active Node
• Responsible for all aspects of user-network
  interface.
• Nature of programming model and abstractions
  supported.
• Addressing and Naming facilities.
• Examples
• SmartPackets, ANTS, CANE

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A A

• AA is a program and associated state capable of
  executing one or more active activities in a
  node, to perform some particular service.
• AA is necessarily portable and dynamically
  installable or removable.
• Examples
• Active Reliable Multicasts, Protocol
• Boosters, Active Congestion Control.

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A N - Architecture
App 1
App 2
App 3
App 1
App 4
App 3
Node OS
Node OS
Transmission Facilities
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Packet Transition
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Implementation Challenges

• The network should be usable
• The network should have high flexibility
• The implementation should be secure
• The network should have high performance

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Killer Arguments

• Efficiency
• Resource Allocation
• Security

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Efficiency

• Hiccups
• Bandwidth demand is growing faster than CPU speed
  bad idea to execute arbitrary programs on
  packets.
• Most programming languages are interpreted JAVA
  byte code, plain interpreter.

• Cure
• Dont propose AN for the core of the Internet.
• Use just-in-time compilation, native code.
• Hybrid architectures (high speed AN!)

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Resource Allocation

• Hiccups
• Fairness in queuing is a problem.
• Cannot guarantee QoS.
• Cannot control Looping packets.

• Cure
• Provide distributed control (Scaling).
• resource reservation in advance, resource
• preemption.
• Limit capabilities of the active packet.

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Security

• Security cannot be limited to peripheral nodes.
• Possible threats
• Overload based Denial of Service
• Unauthorized access to the exposed control
  plane.
• Secure Node doesnt mean Secure Network.

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Security at NodeOS

• Security Enforcement through Authorizations.
• Authorization policies are expressed in terms of
  Access Control Lists, which is a logical 3
  - tuple of the form ltresource, user,
  permissionsgt
• NodeOS has a security policy database and a
  policy enforcement engine.

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Security at EE

• Each EE has it's own protection policy,
• possibly a security database and an
• enforcement engine.
• The programming model that an EE
• supports must also be restricted to ensure
• network security.
• No broad consensus on the division of
• responsibility for policy enforcement
• between the NodeOS and the EE.

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Security in SwitchWare

• Uses ALIEN active loader.
• Code Modules loaded on the fly.
• Restricts access using namespaces.
• Uses a language specification called CAML.

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AN APPLICATIONS

• Network Management
• Multicasting
• Caching
• Active Congestion Control
• Security

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Network Management

• No polling required
• "Patrol" and "first-aid" packets can track a
  problem and rectify it respectively.
• Code moved to node rather than data to management
  center
• ExampleDelegated Management.
• Decentralization helps in scalability, reducing
  delays from responses and effective bandwidth
  utilization.

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Multicasting

• Active internal nodes elegantly solve many
  current problems such as
• NACK implosion.
• Concentrated load of retransmissions.
• Duplication of packets.
• Example ARM
• Suppression of NACK effective retransmission

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Active Congestion Control

• Selective dropping of units, packets or cells
  can be held very efficiently.
• Multi-stream interaction.
• Example APCI
• Backward compatibility with non-active
• nodes on the fly routing employed.

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Caching

• Tradeoff between network based storage
  bandwidth.
• Location time of storage crucial.
• Example
• Self-organizing wide-Area Network
• caches small number of caches within
• routers form large virtual cache.

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Security

• Node Packet conflict.
• Node security by authentication of active packets
  PCC(Proof Correct Code).
• Packet security by Fault-tolerance Encryption.
• ExampleSANE

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AN - Services

• Video on Demand
• VPN
• Multimedia Conferencing
• VoIP / IP Telephony
• Active Firewalling

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AN - Services
Dynamic Proxy Server
Audio Transcoder
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Retrofitting" AN to IP

• The Active IP Option
• Option in the IP header alerts the router to look
  at the packet payload more closely.
• Active Network Encapsulation Protocol (ANEP)
• Adds a header that directs the router.

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AN Legacy
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SmartPackets A Case Study

• Uses Capsule model Code with IP packet
• Programs must be completely self-contained.
• Operating environment provides security.
• Languages
• Sprocket A high level language
• Spanner An assembly level language

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SmartPackets A Case Study

• Uses ANEP to fit with Legacy Networks
• NodeOs JanOs
• EE CANES/ASP
• AA - Network Management

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SmartPackets A Case Study

• Network Management
• Defines 4 types of packets
• Program
• Data
• Error
• Message

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SmartPackets A Case Study

• Security
• For Nodes
• Authentication of packet
• Cryptographic hash of non-mutable fields
• For packets
• Redirection
• Encryption

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SmartPackets A Case Study

• Limitations
• Packet size
• Applications adaptability
• Scope
• Extending for other applications

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Current Work

• Active Nets at DARPA
• ActiveNets at MIT
• ANTS at Washington
• SwitchWare at UPenn
• JANOS OSkit at Utah
• Liquid Software at Arizona
• Panda at UCLA
• NetScript at Columbia
• CANES at Georgia Tech
• Smart Packets at BBN

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Conclusion

• Is Active Network really the future ?

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References

• Darpa
• http//www.darpa.mil/ito/psum1999/J044-0.html
• Switchware
• http//www.cis.upenn.edu/switchware/
• CANES
• http//www.cc.gatech.edu/projects/canes/
• www.ieee.org
• www.citeseer.com