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NetScript: NetScript: A Language Based A Language Based Approach To Active NetsApproach To Active Nets
S. Dasilva, D. Florissi, Y. Yemini (YY) ++Distributed Computing & Communications (DCC) Lab
Columbia University; http://www.cs.columbia.edu/dcc
D
CC
Overview
Background: communications SW architecturesIntroduction to active networksThe NetScript approach
Background: Evolution of Com SW Architectures
The Differences
Closed vertically integratedSlow committee standardsStandardize algorithms &
data formatsFragmented SW market
Open multivendor productFast market standardsStandardize interfaces
Mass market for SW
Intermediate Node End Node
Traditional Com SW Architecture
Rich features built-in closed vertically-integrated elements Signalling protocols coordinate & control Built to last
Process Standardization through slow committees Changes through slow evolution Slow time to market
Com SW: Signalling,
control, mgmt...
Instrumentation
The Emergence of Mgmt
ArchitectureReduced-complexity elements: instrumentation + agentCoordination & control through NMS applicationsSingle protocol, multiple MIBs
ProcessFeatures are designed into MIBsShort time-to-marketThrow-away SW
Agent
Instrumentation
Mgmt App
What Did SNMP Simplify?
SNMP created a new communication SW architectureVendors SW Problem 1: Minimal time-to-marketVendors SW Problem 2: Featurizing productsVendors SW problem 3: Reduced investmentBut…
Complexity is shifted to users OAMIncreasing operations risks & costs dominate end-users
Communications SW: control, signalling, protocols, mgmt
Instrumentation
Bridging The Paradigms
Key new: how to build com SW that enables Fast time to market Competitive featurization Automation of mgmt & control
Driving opportunity: mgmt SW marketEnabling technology: mobile agents
Instrumentation
Agnt Srvc
Introduction to Active Nets
Active Nets = Programmable Nets
Making intermediate nodes programmableBy using mobile agents
Packet capsule approachDelegated agents approach
Instrumentation
Agnt Srvc
Pkt Transport/Switching HW
What Are Active Nets Good For?
Active protocols: Multicast/multimedia protocols, signalling protocols
Active network management & controlConfiguration mgmt; fault mgmt, traffic analysis & shapingSelf-managing networksEnd-end mgmt (e.g., QoS)
Enable new network architectures E.g., STM over IP
Instrumentation
Agnt Srvc
Pkt Transport/Switching HW
Technical Rationale (Continued)
Active network security:Active firewall filters & proxies, active monitoring of intrusion
attacks, active response handlers,
Active application layer: Caching/routing srvrs, filtering/compression, active
phone/video
A Common Computational Model- Packet stream processing- Synthesizing end-end behaviors by composing local components
Market Rationale
Reduce time-to-market increase featurizationVendor-based standardizationCreate mass com SW marketsCreate SW pull for communication HW
Instrumentation
Agnt Srvc
Pkt Transport/Switching HW
The NetScript Approach
Goals & Approach
Goals Language & environment to build, deploy, manage & protect
active services
Approach Language to simplify & unify composition of active elements Program networks --end-end services -- not just nodes Manageability & protection derived from language abstractions
Virtual Active Net (VAN)
Physical Medium
Active Element
OS Environment
NetScript Abstracts Packet Processing
The postscript analogy Layer of abstractions to define page display Separate HW printing engines from app SW
Abstract packet- stream processing primitives Create a layer of abstractions of packet-stream processing Separate HW engines from app SW
A Common Computational Model- Packet stream processing- Synthesizing end-end behaviors by composing local components
Dataflow model: active element = packet stream processor engine
Active elements are composed from boxes (computational channels)Boxes encapsulate computations & resource allocationComposition through interconnectionSynchronization of streams motionsAllocation of underlying resourcesSimple model of interoperability
The NetScript Language
Run-Time Model
Multiple implementation models Java-based: translates to Java, executes on JVM C…: NetScript =>c => bin
Secure delegation protocol
Physical Medium
OS
NetScript Services
JVM
Virtual Active Networks (VAN)
How to deploy, manage & protect large multi-domain active nets?
VAN is a composable unit of end-end service Composition through interconnection, layering and bridging
VAN is a unit of coordinated resource mgmt Mapping active computations to underlying resources
VAN is a unit of protection
The Challenge of Active Nets Mgmt
Active components change dynamicallyHow will MIBs be created? Deployed? How will mgrs monitor, analyze, control ANet?
TransportTransport
MIB
GET/SET/GET-NEXT
TRAP/RESPONSE
ManagerAgent
Instrumentation
Element
NMS
Towards Compiler-Generated Mgmt
Goal: systemic design-time manageabilityManaged properties are integrally designed Compiler-generated instrumentation MIBsA universal MIB structure unifies semantics
Source Dest Counter
FlowMib
Config3Activity2Config2
X Prop1 Prop2 Prop3
YTableEntry
Activity1Config1
XXXEngineMib
Conclusions
Active networks enable new com SW paradigmRich applications potential; revolutionary improvement in
mgmt/control and in network applications and servicesNew roles for network nodes; new relationships between end-
nodes, boundary nodes and intermediate nodes
NetScript provides a language system to supportSystematic, end-end programming of networksDevelopment, deployment and mgmt of active systems