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Active Network

Active Network. Contents. Active Network ? Motivations Lead Users New Applications Programmable Switch Capsule Programming Model Ongoing Research Projects ABONE Hard Problems. Active Network. Active Router. Active Packet. Host. Active Router. Active Router. Active Packet.

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Active Network

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  1. Active Network

  2. Contents • Active Network ? • Motivations • Lead Users • New Applications • Programmable Switch • Capsule • Programming Model • Ongoing Research Projects • ABONE • Hard Problems

  3. Active Network Active Router Active Packet Host Active Router Active Router Active Packet Active Router Host Active Packet Active Router

  4. AN : What is it ? • Software-intensive network architecture • Network switches perform customized computations on the messages flowing through them • Customizable on a per user or per application basis • Individuals can inject programs into the network • Applicable to Internet : overlay or substitution • DARPA sponsored research projects

  5. Motivations • Internet is difficult to maintain : 8 years from prototype to deployment (backlogs are multicast, authentication, mobility extension, RSVP, IPv6) • Mismatch between user requirement change rate and the physical system change rate • Router/switch is proprietary hardware plus customized software (mainframe mindset)

  6. Approaches • Virtualized approach : software detached from hardware (anyone can provide innovative software) • Protocol components instead of layers • Equivalent computational model instead of equivalent program at each node

  7. Lead Users • Firewall • Web Proxy • Mobile/Nomadic Router • Transport Gateway • Application-specific Gateway • Multicast (MBONE) • RSVP (RBONE) • IPv6 (6BONE) • AIN

  8. New Applications • Merging and distribution of information • User-aware network protection • Active network management • Router, switch, packet analyzer, firewall, RTP mixermultimedia transcoder, web streaming, congestion control, Internet phone, NACK filtering in multicast

  9. Two Approaches • Programmable Switches • Capsule

  10. Programmable Switch • Discrete approach : program loading is separated from message processing • Easy migration • Program injection by authenticated operators • Upon header examination, appropriate programs are dispatched to operate on message contents

  11. Capsule • Integrated approach : every message is a program (a la Postscript) • capsule = program + data

  12. Programming Model • Program Encoding • Mobility • Safety • Efficiency • Common Primitives • change header/payload/length • access to node’s environment (address, time, link status) • control packet flow (forwarding, copying, discarding) • access to node storage and scheduling • Node Resources and their Allocation • physical resources (bandwidth, processing capacity, storage) • logical resources (routing table, MIB)

  13. Program Encoding • Source Level : script language • Tcl • NetScript • Intermediate Representation • Java • Object-code Level • Omniware

  14. Research Projects • Columbia NetScript • MIT SpectrumWare, ANTS • Upenn SwitchWare, PLAN, Security • Bellcore OPCV2, Active Router, Protocol Booster • BBN Smart Packet • GeorgiaTech CANES • UArizona Liquid Software • UCLA/LBNL Adaptive Web Caching

  15. SwitchWare • Upenn + Bellcore • SwitchWare switch = I/O + program (computer) • Hierarchical Layers : • Active Packet, Switchlet, Active Router Infrastructure Network Active Packet Active Packet Active Packet switchlets Active Router Infrastructure

  16. SwitchWare (cont’d) • Active Packet • mobile program (code + data) • PLAN : Programming Language for Active Networks • Switchlet • dynamically-loaded extensions, not mobile • not lightweight, tight security mechanisms • Secure Active Network Environment (SANE) • static, secure foundation

  17. SwitchWare Application • Active Network Striping for Software Scalable Bandwidth Channel 1 SwitchWare Switch B SwitchWare Switch A Host A Channel 2 Host B Channel 3 Channel 4

  18. Pseudocode • Switchlet for sender stripingWhen Arrives(Packet, InPort){ Send ((SequenceNumber, Packet),OutPort); OutPort := (OutPort+1) Mod Channels;}

  19. Pseudocode • Switchlet for receiver stripingWhen (Arrives ((SequenceNumber,Packet), InPort)){ If (InOrder(SequenceNumber,Expected)) { Send (Packet,OutPort); Expected:=Expected+1; While(CheckQueue(QueueName,Expected)) { Dequeue((Expected,Packet)); Send(Packet,OutPort); Expected:=Expected+1; } } else Queue((SequenceNumber,Packet),QueueName); }

  20. ANTS (Active Node Transfer System) • Capsule-based active network toolkit • written in Java, protocols carried as bytecodes • Capsules carry program state as they travel • they are external representation of object instances • Protocol code is demand loaded by nodes • depends on previous node and caching • Nodes provide API for protocol writer • soft-state cache, routing primitives

  21. ANTS Goals • Today’s networks lack flexibility … • Active networks are an appealing solution, but no convincing demonstration that they can work … Seek to allow new network services to be introduced rapidly. Evaluate the hypothesis that they can provide useful flexibility at a reasonable security/performance cost.

  22. ANTS Architecture • Approach • uncoordinated introduction, automatic deployment • application-specific protocols used “on-the-fly” • Model • programmable routers generalize IP forwarding • mobile code used to implement new services • Goal • show feasibility/usefulness, explore tradeoffs

  23. ANTS Glossary • Node • programmable router that implements services • Capsule • generalized packet (header + data + program) • different capsule types have different programs • Protocol • communication rules that provide a service • codified as set of related capsule types • Application • network client that uses services via protocols

  24. Capsules are Generalized Packets • carry the program and protocol by reference using a fingerprint to prevent code spoofing • header includes at least fields for default forwarding, resource limits and source identification Protocol+Program Id Header Data Node Node Capsule

  25. Node Operating System • hosts user-defined protocols • capsule API: soft-storage, routing, … • admits new protocols at its discretion • protects network/protocol integrity • executes untrusted code, limits resource use • provides each protocol with its network “view” • distributes code among nodes

  26. Code is Loaded at Routers • application provides code at end systems, while node loading is triggered by capsules need to be efficient, adaptive, and load-limited previous node loading node load request time load response

  27. Smart PacketsA DARPA-Funded Research Project A. Jackson, G. Lauer, C. Partridge, D. Rockwell, B. Schwartz, W. Zhou

  28. Overall Goal • Our goal is to add programmability to management and diagnostic packets • constrained scope realizable in individual packets • flexible and rich programming environment as possible in one packet • code authentication and run-time authorization

  29. smart pkt compiler assembler data smart pkt data smart pkt data Component Overview Router 1 execution environment • Program in single packet • Hop-by-hop evaluation • Data returns to source injector Router 2 authentication display execution environment Source execution environment Destination

  30. ABONE • Experiment prototype active node implementations • MIT (ANTS) -- ISI (ANTS)MIT (ANTS) -- UArizona (ANTS)ISI (ANEP) -- UKansas (ANEP) • Active Network Encapsulation Protocol (ANEP) • Active Network Overlay Network (ANON)

  31. Hard Problems • Security • Management • Applications • Performance • Interoperability

  32. What to do ? • Initiate research programs on advanced Internet, and active network is one of them. • Develop new generation of low cost network nodes (router, ATM switch) with open architecture. • Close collaboration is required among different research communities : programming language, operating system, object technology, and networking • Capitalize on selected application servers : hierarchical web caching, multimedia stream server • Build testbed network

  33. R&D Proposals • Low Cost Switch with Open Architecture • Multicast Multimedia Application with loadable software at switches • Conferencing • Internet phone • Stream service (broadcasting, interactive)

  34. Discussions • AN may be a solution to IP vs. ATM debate. True or not ? • Can AN switches replace public telco switches? • Proliferation of user-defined switch functions and associated applications will create new industries and companies like Microsoft will die out. Will it happen ? • What is our role (HSN community) in this business ?

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