Review of: A Survey of Programmable Networks

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Review of A Survey of Programmable Networks
Research Seminar on Reconfigurable
Hardware http//www.arl.wustl.edu/lockwood/class/
cs6812/
CS6812 Fall 2002
Lockwood

• Paper by
• Andrew T. Campbell (Columbia), Herman G. De Meer
  (Univ. Hamburg), Michael E. Kounavis (Columbia),
  Kazuho Miki (Hitachi), John B. Vicente (Intel),
  and Daniel Villela (Columbia)
• Published in
• Computer Communications Review
• April 1999
• Original copy on-line as
• http//www.acm.org/sigcomm/ccr/archive/1999/apr99/
  ccr-9904-campbell.pdf
• Survey by
• John Lockwood

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The Challenge

• Provide ability to
• Rapidly create new services
• Rapidly deploy new services
• Find a way to manage
• Open the network to new services
• Maintain control
• Maintain security

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Style of the Paper

• A Survey of existing work
• Broad, not deep, coverage
• Large number of references
• 49 papers cited
• Provides taxonomy of projects

4
Network APIs

• Opensig
• Standard Interface for switches, routers
• Hardware modeled with open network interfaces
• Managed by middleware, like CORBA
• Telecommunications approach
• Control and transport separate
• Active Network (AN) DARPA Approach
• Active packets with Code and Data
• Capsules Executable programs, like Java
• Much more dynamic than Opensig

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Programmable Network Model

• Higher level services composed from lower-level
  API calls
• Separation Between
• Transport
• Video packets
• Control
• RSVP
• Management
• SNMP

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Node Operating Systems

• Functions
• Signaling
• Control
• Management
• Downloading new boot images
• Properties
• Closed
• Proprietary
• Not open to 3rd party development
• Example
• CISCO IOS

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Node Interface

• Lowest level of programmability
• in this framework
• Sits above node hardware
• Like a device driver Fig. 2
• Node Interface performs
• Access and control of node resources
• Communication Services
• Local significance Only
• Not a part of a group

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Network Programming Interface

• Controls multiple nodes
• API provides calls for network-wide services
• Service composition, control, resource management
• Constructed from
• Scratch, -or-
• Existing distributed computing environments
• xbind Corba
• Mobiware Corba
• Virtual Machines
• Active Network Transport Systems (ANTS)

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Programmable Network Architecture

• Network Services
• Services available to end systems
• Network Algorithms
• Transport, signaling/control, management
• Multiple time scales
• Network state management

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Programmable Networks

• Characteristics
• Network technology
• QoS-capable ATM
• Scalable Internet
• Limited Mobile
• Level of programmability
• Granularity
• Time scale
• Communications abstraction
• Virtual switches, active nodes, channels
• Architecture domain
• Signaling, management, transport

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Granularity of Control

• Course Grain
• Single packet can affect all future packets are
  routed
• Fine Grain
• Single packet (capsule) can only affect how it is
  routed

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Network Technology

• IP Networks Smart packets U. Kansas
• Java classes
• Resource controllers
• Interface to Node
• Node managers
• Limits on CPU/resource usage
• State managers
• Control how much state a packet may leave at a
  node

13
Level of Programmability

• Capsules
• MIT
• Carry code and data
• Uncoordinated deployment of protocols
• Example ANTS
• Multicast services
• Mobile routing
• Application-level filtering

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Levels of Programmability continued

• Switchware
• Univ. of Pennsylvania
• Node-resident services invoked by commands in
  packets
• Off-line verification to ensure that low-level
  extensions are safe
• Functional languages
• Caml, PLAN

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Levels of Programmability continued

• Composition Languages CANES Project
• University of Kentucky Georgia Tech
• Control sequence which components are executed
• Control on how data is shared between components
• Control data shared between components
• Invocation Methods
• Events that cause a composite to be executed

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Communications Abstraction

• NodeOS
• Lowest level of reprogrammable network framework
• Provides an execution environment for
• Treads Computation
• Memory Storage
• Channels Communication capacity
• Flows Admission Control
• Active Network Encapsulation Protocol (ANEP)
• Portability against physical nodes

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Communications Abstraction (Continued)

• Netscript
• Columbia University
• Functional Language
• Strongly typed language
• A Postscript for an Active Network node
• Tempest
• University of Cambridge
• Multiple control architectures for ATM
• Switchlets Logical elements, partition of switch

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Communications Abstraction (Continued)

• Darwin Project
• Carnegie Mellon University
• Resource Management Middleware
• Supports QoS
• Components
• Xena Request Broker
• Can implement traffic control
• Beagle Signalling Protocol
• Can implement RSVP

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Communications Abstraction (Continued)

• Smart Packets Project
• BBN, not Kansas
• Encapsulation of packets ANEP
• Applications written in
• Sprocket C-like language with security -or-
• Spanner Low-level assembly-like language
• Program Example
• MIB data retrieval

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Common Properties Table 1

• Common Goals
• Composing services (13)
• Network management (3)
• Virtual networks (2)
• Enabling overlays (1)
• Programming Methodologies
• Java 4, CORBA/IDL 3, Others
• Level of Programmability
• Dynamic 10, Quasi-static 3, Static 1
• Security
• Switchware

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Conclusions

• Innovations
• Separate form from function
• not hardware from software, as noted by author
• Make programmable interfaces available
• Virtualize the network infrastructure
• Provide rapid creation and deployment of new
  services
• Allow coexistence of different network
  architectures over the same physical network

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Questions and Discussion

• What was right with the Active Network model?
• What was wrong with the Active Network model?
• Can higher-level network layers be built on top
  of underlying networks that change?