Network Computing Services, Inc. Real-Time Visualization of IP Streams over Switched WANs Real-Time Visualization of IP Streams Over Switched WANs Timothy

Network Computing Services, Inc.Real-Time Visualization of IP Streams over Switched WANs

Real-Time Visualization of IP Streams Over Switched WANs

Timothy J. SaloNetwork Computing Services, Inc.

[email protected]

[email protected]

http://www.msci.magic.net/visualization

6/13/00 Copyright ©2000 Network Computing Services, Inc. 2


Contents

• Our objectives• Our real-time visualization tool• Our offer• Our research (time permitting)



Overview

• DARPA-funded research project to explore the behavior of IP protocols in switched environments (particularly in WANs)

• We believe that the mapping of IP streams onto a collection of switched connections is an important, general problem

• We have developed a real-time visualization tool

• We are looking for places to deploy the tool



Overview

• We observed apparent anomalies in MAGIC wide-area IP/ATM testbed

• Anomalies appeared related to the protocols that map IP streams onto underlying switched connections (ATM SVCs)

• We wanted a real-time, global, fine-grained view of the behavior of IP and the underlying switched connections



Origins

• We wanted a real-time view of the network

Demo



The Visualization Tool

• Displays graphically, in real-time, IP-related streams in wide-area IP/ATM internets

• Focuses on mapping of IP streams onto switched connections

• Allows researchers to interactively control the visualization

• Allows researchers to store and replay data• Initially, supports IP/ATM




• Completely written in Java– Compiles under Java 1.1– Works better under Java 1.2– Will be released with Berkeley-style copyright

• Object-oriented design– UML description of class hierarchy

• JavaDoc documentation




VisualizationSubsystem

Live, prerecordedor animatedvisualizations

Data Collectionand AnalysisSubsystem

IP/ATMWAN UnderObservation

SNMP

Live orPrerecorded Data

Animations




• Composed of two components– Data collection and analysis subsystem– Visualization subsystem




• Data collection and analysis subsystem– Extracts data from the network using SNMP– “Auto-discovers” network topology– Creates a model of the network topology/state– Updates the model as the network state changes– Sends “model updates” to the visualization

subsystem• serialized Java objects• complete model can be created from updates• model updates can be written to file




• Visualization subsystem– Runs as an applet or an application– Receives model updates from the data collection

and analysis subsystem (or a file)– Maintains a model of the network topology/state– Displays the state of the network under operator

control




• Visualization system running on small networks

• Less information in MIBs than expected– Standard MIBs not always implemented– MIB often designed to expose variables, not

support operations or research

• We want to deploy this on larger networks



Visualization Demo

• University LAN Demo

• Internal LAN Demo

• Local Demo



Our Offer

• We are looking for moderate-sized networks on which to deploy our tool!– Wide-area networks or campus networks– IP over ATM– Perhaps, MPLS

• We will:– Install and operate the tool– Put a person on site, if necessary– Add support for your switch vendor’s MIBs– Extend the software, time permitting



More Information

•http://www.msci.magic.net/visualization/•[email protected]

CreditThis work is sponsored by the Defense Advanced Research Projects Agency (DARPA) under contract number

F30602-98-C-0211.



Terminology

• stream an aggregate of one or more flows, treated as one flow for the purpose of forwarding in L2 and/or L3 nodes



Our Research

• We believe that making IP protocols work gracefully over switched connections is a general problem

• Switched connections are ubiquitous– IP/ATM (Classical IP, LANE, NHRP MPOA)– MPLS– Tunnels (Mobile IP)– Reservations (RSVP)– Wavelengths



Our Research

• Many IP protocols don’t work well with switched connections– Routing protocols (rapid topology changes)

• Compare process of installing a new leased line with establishing a switched connection– Adding a leased line involves lots of manual

processes and time (~100 days)– Adding a switched connection (in some sense)

compresses all of this work into 100 msec



Our Research

• Where can things go wrong in IP over switched services WANs?– Maintaining a collection of connections

• Stability

• Why is there a connection between these nodes? Why not one here?

• Response to resource depletion

– Assigning flows to connections

• Why do packets take that path?

– Behavior of IP/switched-services “control” traffic versus data



Our Research

• Our model of IP-over-switched-services protocols includes four functions:– Maintain a collection of connections

• Connections may be provided by an underlying link-layer network

• Connections maintained by IP software– Maintain routing tables for switched connections– Classify packets into streams – Assign streams to switched connections

• We believe this model has general applicability



Our Research

• Problems can be introduced at:– Network configuration time– Protocol design time



Religious Issues

• ATM, virtual circuits, traffic engineering, … easily generate a lot of discussion

• I believe that interactions between switched connections and the IP protocols include most of the interesting issues in this area

• I believe that many IP protocols don’t work well with switched connections– Routing protocols (rapid topology changes)– Traffic engineering (automated network design)



Religious Issues

• I believe that switched connections are pervasive in IP networks– Switched link-layer services– Within IP protocols

• Mobile IP, MPLS, VPNs, …

• ATM is not the issue– Use ATM when it is cost effective [and works] –

nothing more needs to be said– The cost characteristics of ATM have clearly altered

the technical and political evolution of the Internet



Religious Issues

• “Virtual circuits” are not the issue– I don’t think I can really define a virtual circuit

anymore…– Should we avoid frame relay because it uses

“virtual circuits”?– Unknown or variable bandwidth might be an issue,

but it’s not a major issue

Documents

Network Computing Services, Inc. Real-Time Visualization of IP Streams over Switched WANs Real-Time Visualization of IP Streams Over Switched WANs Timothy