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