NetWork Simulator - NWS

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NetWork Simulator - NWS

• Fouad LABRIKI
• Fouad.labriki_at_libertySurf.fr
• 02-10-2003

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OVERVIEW

• Overview
• NetWork Simulation
• NwCompiler
• MibCompiler
• Network Simulator deamon nwsd
• Java GUI
• NwModel
• GEF
• NwGUI

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NetWork Simulator - NWSOVERVIEW

• What is it?
• Application for creating simulated netwoks
• Context of usage
• SNMP-based netwok management application
  example NNM
• Whats designed for?
• Development, Support, Training, Evaluation, Demo,
  Testing

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NetWork Simulator - NWSOVERVIEW

• NWS 2 main parts
• Java GUI
• intuitive java GUI for designing networks
• Network simulation
• MIBcompiler MIB compiler
• NWcompiler simulated network items into
  Database.
• NWSD ICMP/SNMP communication deamon

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NetWork Simulator - NWSOVERVIEW
mibText
Java GUI ( remote part)
nwText
nwsd
Simulation Station
nwCompiler
ICMP/SNMP
nwDB
Management Station (NNM) NWS Java GUI
The rest of the real network
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NetWork Simulator - NWSOVERVIEW

• Vocabualry
• Management station
• Simulation station
• Java GUI station
• S-Network

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NetWork Simulation NwText

• Stores textual description of the S-Network
• Devices names (system/switch/hub/switch/routers)
• IP addresses
• MAC addresses
• .
• All statical S-Network infromations are stored in
  this file
• Uses a formal syntaxe designed for this purpose
• Syntaxe called NWSymS

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NetWork Simulation NwText - NWSymS

• ltNetwork Namegt
• BEGIN
• NODES
• NODE .
• NODE .
• .
•   NODE .
• END

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NetWork Simulation NwText - NWSymS

• NODE
• HOSTNAME hostname of this node
• NODETYPE device type (computer, router..),
  constructor, OS version..
• INTERFACES
• INTERFACE LAN interfaces attributes IP _at_,
  Mac _at_
• TABLE_ARP ARP entries of this LAN
  interface
• INTERFACE LAN interface attributes IP _at_,
  Mac _at_
• TABLE_ARP ARP entries of this LAN
  interface
• TABLE_ROUTE route entries of this node

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NetWork Simulation NwText

• Can be created manually (using a text editor)
• User has not to create this file manually
• User always uses Java GUI to draw the netwok
  graph
• Java GUI translates the network graph to text
  file according to NWSymS syntax

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NetWork Simulation NwCompiler

• Transforms NwSymS text file (NwText) into a NDM
  database nwDB
• Can be initiated from the Java GUI
• Can be started in the Simulation Station by
• /opt/nws/bin/nwcompiler -d -f ltfilenamegt
• Developped using yacclex

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NetWork Simulation NwDB

• The database that reflects the S-Network
• Used by nwsd deamon to answer SNMP/ICMP requests
• Current version is NDM based
• Advantge
• Very simple
• Inconvenient
• One need to develop its own database engine
• Only nwsd deamon access the database
• We prefer the next release implementation

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NetWork Simulation NwDB next release
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NetWork Simulation MibText

• Gathers all the MIBs texts recognizable by NWS
• Concatenation of standrd and non standard Mibs
• Located under /etc/opt/nws

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NetWork Simulation MibCompiler

• One of the most complex and bigest parts of NWS
• Real MIB compiler
• reads the mibText file
• compils it into the internal MIB tree structure
• Recognizes the ASN.1/SIM syntax
• ASN.1 macros problem workedaround
• Currently started by nwsd deamon
• Yacclex used to develop this module

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NetWork Simulation nwsd deamon

• Achieves the most part of the work
• mib compilation (executes MibCompiler command)
• Real icmp/snmp protocol implementation
• Based on DLPI library
• Can be startd manually on the simulation station
• /opt/nws/bin/nws -d
• User always starts nwsd from the GUI

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Read the next Ethernet frame FRM
No
Yes
Yes
No
No
Yes
No
Get the node destination,ND of IpFram and
Interrgate NwDB
Yes
No
Yes
Create an SNMP answer Frame and send it to the
management Station
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NetWork Simulation Future Architecture
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mibText
nwText
Java GUI (the remote part)
mibCompiler
nwsd
nwCompiler
nwDBs
mibBin
- nwDBs  nwDB database server. - FM
D Frame Management Daemon.
FMD
nwDB
ICMP/SNMP
Management Station NNM NWS Java GUI
The rest of the real network
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Java GUI Overview

• Network editor
• Based on three modules
• GEF (Graph Editor Feature)
• NwModel
• NwGui

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Java GUI GEF

• What is it?
• Java class library for constructing graph editing
  applications
• Infrastructure to custom graph drawing programs
  for particular domain
• Is not a drawing program

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Java GUI GEF

• Why GEF?
• Framework for graph drawing programs
• Several advantages versus other works
• Extensibility
• Simplicity
• high-quality user experience
• Open Source

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Java GUI GEF

• Two main levels in the GEF representation
• Net level
• holds logical objects having application specific
  data and behavior Nodes, Edge
• Diagram level
• Set of Figures to visually depict the net and
  various annotations Figs

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Java GUI GEF Architecture

• LayerManager
• Collection of layers
• Layers
• Clear sheets of plastic
• LayerDiagram
• Layer with collection of figures
• LayerPerspective
• Assumes model is connected graph
• Access the model through interfaces

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Java GUI GEF GraphModels

• GraphModel supports traversing the graph
• GraphNodeRenderer and GraphEdgeRenderer are class
  factories for creating
• displayable Fig instances from the model's nodes
  and edges.
• Uses GraphModel to map Figs in a diagram to
  application specific objects, Nodes
• Analogous to mediators found in Java's Swing user
  interface library
• TreeModels
• TableModels

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Java GUI GEF UML class diagram
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Java GUI NwModel

• The model retained to represent the IP- network
  datastructure
• Better described using its UML class diagram

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1

2
1

0..1
1
1

• Hostname
• isIPforwrd

• Ip Dest.
• NetMask
• pNext
• metric

1

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Java GUI NwGui
Navigation window
Interface window
ToDo window
Details window
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Java GUI NwGui
To add a cable
The toolbar
To add a compute
To add a router
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Java GUI NwGui
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Java GUI NwGui
Nodes table
Routing table
LAN interfaces table
ARP table