1 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Cloud Models A cloud can represent a backbone network Helpful for modeling packet transmission through an external network or ISP Clouds have attributes such as Latency and Packet Loss Ratio ATM and Frame Relay clouds support PVCs through the network

2 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Model Architecture Within each IT Guru model is a full protocol stack Each protocol is modeled individually to simulate exactly the protocol’s specified behavior All models are thoroughly tested for high fidelity Instructor Demo: Explore Model Architecture with OPNET Modeler

3 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Organizing Models - Object Palettes An object palette is a graphical dialog box that displays a group of node and link models. Change palettes by selecting a model list from the pull-down menu. The palette always contains a subnet object. Object palettes can be customized to contain only the nodes and links that you requires. There are several different methods for customizing palettes.

4 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Customizing Palettes Keyword Model List Startup Wizard

5 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Customizing Palettes - Model List Method LAB REFERENCE For a later lab we will use the model list method.

6 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Creating New Devices Although OPNET Modeler includes hundreds of standard and vendor devices, you may need to customize models. There are several ways to create new devices or derive models from the existing database to custom specifications. Two methods discussed here to change and existing model Modeling new devices and protocols discussed later in course

7 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Deriving New Models Modeler allows you to select an existing standard or vendor model and derive a new model based on the parent model’s specifications. You can then alter the attributes of the newly derived model to reflect a device that will be used in the network simulation.

8 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Deriving New Models

9 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Advantages of Deriving Models Makes it easy for you to configure and integrate models for specialized needs. Allows you to benefit from past work by basing new, specialized models on previously created ones. Gives you benefit of control over certain aspects of a new model while preserving its essential structure. Allows creation of a new device that has preset and possibly hidden attributes.

10 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Device Creator Provides the ability to automatically create a particular device with a specific configuration. Typical devices include routers, switches, hubs, bridges, vendor specific devices, and LAN models. In the “Topology” pull-down menu.

11 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Advantages of Device Creator Allows you to select any number of interfaces and protocols that a device will need to support. Provides you more control over memory efficiency, reducing simulation run-time.

12 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Object Attributes All Modeler objects have attributes Attributes define the object and control its behavior Second attribute is “model” – this is the filename of the object Attribute values may vary between objects of the same model Example: Two routers of the same model may have different routing parameters, two demands may represent different amounts of traffic Attributes may have sub-attributes To view or change an object’s attributes Right-click on the object Select “Edit Attributes” or “Advanced Edit Attributes”

13 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Object Attributes (cont.) All objects have attributes that control aspects of their behavior. Attributes may vary from one model to the next. Attribute values may vary between objects of the same model type. Right click on an object and select “Edit Attributes” to view or change its attributes.

14 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Selecting Objects Select objects to modify, cut, delete, move, or copy them Several methods to select multiple objects: Shift-click or Control-click Right-click and choose Select Similar Nodes/Links/Demands Selects all objects with the same model name Edit / Select Objects Advanced object selection used to select objects with certain attribute values Excellent way to explore configuration of an existing network model Edit / Find Nodes Select objects based on object name Draw a selection box around a group of objects Click on empty workspace to deselect all objects

15 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Group Attribute Assignment A group of objects can have their attributes assigned simultaneously by using the “Apply Changes to Selected Objects” button. Note that selected objects that do not contain the attribute being changed will not be affected by the group assignment.

16 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Where to Get Help To view the manual, choose Product Documentation from the Help menu. Model help is accessed by right-clicking icons in the object palette or by right clicking objects in the Project workspace and selecting “View Node Description.” Click the question mark in attribute dialog boxes to view the description of that attribute. Tool Tips: place your cursor over any object and wait one second to get a brief description of that object.

17 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Searching Product Documentation

18 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Searching Using Global Index

19 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Lab 1: Workspace Purpose: “Play” with features of the Project Editor Use the Device Creator and node derivation to create new node models Modify attributes’ values in order to model non-default behavior Search the product documentation

20 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Building a First Network

21 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. OPNET Workflow – Inputs and Outputs Virtual Network Environment Traffic, Topology, and Configuration Application Trace Flow Analysis: Visualize and study steady-state data flow, capacity planning, failure analysis – extensive reporting NetDoctor: Operational configuration validation – protocol-specific and policy-based DES: Simulates precise protocol effects for capacity planning, tuning protocol behavior, response time engineering, technology migration, QoS, etc. ACE: Application performance troubleshooting: visualize performance, diagnose problems, explore solutions MVI, VNES, GUI Sniffer, OPNET Application Capture Agent, etc. Steady-state Throughput/Util; 100+ Reports; Path/Failure Analysis Flow Analysis Configuration validation reports NetDoctor Graphs, web reports, charts, for all time-varying network performance metrics (e.g., app response time, queue depths, convergence time, protocol behavior, etc.) DES Application Visualization, Diagnosis, Analysis, Protocol Decodes ACE

22 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. DES Workflow One project can contain many scenarios The Startup Wizard can be used to quickly and easily create new scenarios. The Project workflow consists of: Create/Import Topology/configuration Use NetDoctor for configuration/topology/rules validation Create/Import Traffic Use Flow Analysis for capacity planning, routing, failure/recovery studies Choosing statistics to be collected Running simulation Viewing results Duplicating scenario Running Simulation Comparing results

23 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. DES Concept: Topology

24 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Project Editor and Topologies Project Editor Networks are modeled and created in this editor The first step is to specify project and scenario names and select how to create the topology Topology can be created or imported from Empty Scenario - built manually ACE traffic file HPOV Network Node Manager Device Configuration files Circuit Switched Text files ATM Text files XML VNE Server

25 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Projects and Scenarios Capacity Planning Project Baseline Scenario Scenario With Upgraded Links Baseline Scenario With Doubled Traffic A scenario is a snapshot of the entire network configuration, topology, and traffic

26 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. How to Create a New Project/Scenario Start a new project Name the project/scenario Choose initial topology Choose network scale

27 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. How to Create a New Project/Scenario (cont.) 5)Specify Border Maps 6)Select default technologies 7)Verify settings 5 6 7

28 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Rapid Configuration An aid to deploying multiple network objects Available topologies include Bus Full Mesh Randomized Mesh Ring Star Tree

29 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Rapid Configuration - Topology menu Rapid Configuration 1 3 2

30 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Verify Links Ensures that point to point and bus links are connected properly Checks that: There are enough transmitters and receivers to support all of the incoming and outgoing links The data rates of the connected transmitter and receiver match the data rate of the link The technologies of the devices’ transceivers and links are identical Check bottom of window for number of inconsistent links – they will be marked with red X’s

31 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Object Attributes Subnetwork, node, and link objects in Modeler have attributes that define the object, and control its behavior in a network model. Object attributes are configured by right-clicking on the appropriate subnet, node or link.

32 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. DES Concept: Traffic Modeling

33 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Traffic Types Three different types of traffic Loads Also called “Device/Link Loads” Represent percentage of capacity being used Can be imported or manually created Flows Visualized as demand objects Can be imported or manually created Packets Provide detailed performance statistics Delay, response time, jitter Represent different types of application traffic Can be imported from optional ACE module or manually created All three can exist simultaneously in the network model

34 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Link Loads Represent utilization of individual links Values are represented in percentage utilization for each time period Utilization A->B Utilization B->A To set link loads manually: Right-click a link, edit attributes Expand “Background Utilization” attribute Set utilization percentages for multiple time periods To import data from management platforms: Traffic / Import Device/Link Loads MRTG InfoVista Concord eHealth-Network Text Files

35 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Flows Represent flow of network traffic between node pairs Flows are represented in bits/sec and packets/sec Flow data can be imported from many sources: Cisco NetFlow (AS Aggregation or No Aggregation) Cflowd NetScout NetScout Ngenius NAI Distributed Sniffer / Sniffer Pro Agilent NetMetrix Spreadsheet / text files ACE traces Add new flows manually by choosing: Protocols / IP / Demands / Configure Traffic Demands Among Selected Nodes Special flows appear in palettes ATM Flows in ATM palette IP Flows in Internet Toolbox palette

36 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Flows Flows are a type of traffic demand. Demands appear as dotted blue lines from source to destination. Right-click a traffic demand to edit its attributes or hide the demand Use View / Demand Objects to hide/show all demands Use Traffic / Flows Browser to quickly examine many flows

37 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Packets Only used for discrete event simulation (DES) Represent individual packets in network Application traffic LSAs Application Configuration node used to globally define application traffic LSAs automatically sent by routers during simulation Capture the transient behavior of the network Convergence Latency Queue depth Protocol effects Verify Service Level Agreement compliance

38 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Traffic Tradeoffs Only simulated in DES Configured manually Simulations can be lengthy Provides very detailed statistics: convergence time, packet loss, protocol interactions, delay, jitter Packet Sometimes difficult to obtain flow data for entire network Simulations will route flow data over network according to routing protocol settings Good for failure studies Flow Can’t be rerouted in failure case Provides no detail about traffic ingress/egress points Usually easiest data to obtain Visualize current load on network Load DisadvantageAdvantageTraffic Type

39 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Explicit Application Traffic – Overview Explicit application traffic Common networked applications ACE Custom applications

40 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Application Model Architecture – Explicit Traffic Clients reference Profile Definition to find out which applications to run Servers reference Application Definition to find out which applications to support Profile Definition references Application Definition to find out which applications to run ONLY Custom and ACE applications reference Task Definition to find out which phases to run

41 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Common Networked Applications To represent a person using and downloading files: Edit Application Config node to support and FTP Define the level of use or use a predefined level Define a user in the Profile Config node that uses the and FTP applications you just configured Set the client to support the user profile you just created Set the server to support the and FTP applications Instructor Demo

42 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Common Networked Applications Predefined applications model common networked applications such as , FTP, web browsing and database access Pre-defined generic applications are configurable through attributes of the Application Config utility node

43 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Common Networked Applications Includes various network applications with pre-defined load levels View and edit these settings by selecting a predefined load and then selecting “Edit…” Off, PCM Quality Speech, PCM Quality and Silence Suppressed, Low Quality Speech, Low Quality and Silence Suppressed, IP Telephony, IP Telephony and Silence Suppressed, GSM Quality Speech, GSM Quality and Silence Suppressed, Edit Voice Off, Low Resolution Video, High Resolution Video, VCR Quality Video, Edit Video Conferencing Off, Low Load, Medium Load, High Load, EditRemote Login Off, Text File, B/W Images, Color Prints, EditPrint Off, Light Browsing, Heavy Browsing, Searching, Image Browsing, Edit HTTP Off, Low Load, Medium Load, High Load, EditFTP Off, Low Load, Medium Load, High Load, Edit Off, Low Load, Medium Load, High Load, EditDatabase Off, EditCustom

44 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Common Networked Applications Step 1: Application Configuration Place an Application Configuration node in the network Edit Attributes and edit the Applications Definitions attribute Define the applications and levels of use for each Step 2: Profile Configuration Place a Profile Configuration node in the network Edit attributes and edit the Profile Configuration attribute Assign applications to each profile, which represents a user of workstation or LAN Step 3: Configure clients Edit attributes, edit the Application: Supported Profiles attribute Assign profiles to each client Step 4: Configure servers Each application used in the network needs a server to support it Edit server attributes and edit the Application: Supported Services attribute

45 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Characterized Applications With ACE, users can model “real” networked applications Import and characterize packet traces with ACE OPNET Application Capture Agents can capture application traces

46 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Custom Applications Can be multi-tiered applications Defined as one or many tasks Task can comprise many phases

47 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. DES Concept: Choosing Statistics

48 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Choosing Statistics - Mechanics Choose statistics to collect: DES / Choose Individual Statistics List of statistics appears Types of statistics: Global: relate to network as a whole Node: collected on individual nodes Link: collected on individual links Common statistics: Global: application response times Node: delay, delay variation Link: utilization, throughput, queuing delay

49 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Choosing Statistics - Mechanics Collect statistics on individual nodes and links Right-click the object and Choose Individual DES Statistics This option is good choice for models with large number of nodes or links – cuts down on memory required for simulation Good for getting more detailed information on certain devices/links

50 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Descriptions of Statistics To obtain complete definitions of statistics, right-click on the statistic in the “Choose Results” window and select Statistic Description.

51 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Statistic Collection Modes There are three types of statistic collection modes All values mode: Every data point is collected from a statistic. Sample mode: The data is collected according to a user- defined time interval or sample count. For example, you could specify that data be collected every 10th simulation second or every 10th data point. Bucket mode: All the data points are collected over the time interval or sample count and are processed according to a user-defined parameter-- max, min, sum, count, sample average or time average. (This is the default mode.)

52 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Understanding Statistics To run simulations with useful results, it is essential to define the goals of the simulation and to understand the statistics that are needed to measure those goals. Browse available statistics and view their definitions. Understand the default collection mode to help interpret results.

53 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Choosing Statistics - Advanced Optional Step: Change statistic collection mode Default is bucket mode: collects up to 100 data points per simulation Simulation time divided into 100 segments Average value during each segment becomes one point on graph Solutions when results are not granular enough: Change collection mode Increase number of data points collected per statistic Shorten simulation time

54 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Using Statistics Effectively If you collect utilization statistics using default bucket mode and see the graph below, are there enough data points to tell the whole story?

55 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Using Statistics Effectively Give extra precision to the link statistics for one link of interest

56 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Using Statistics Effectively Utilization results with extra precision, link reaches maximum (100%) utilization Throughput varies from 60,000 to 256,000 bits/sec

57 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. DES Concept: Running Simulations

58 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Running Simulations Understanding Statistics Simulation Log Viewing Simulation Results

59 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. Simulation Mechanics Run simulation DES / Configure/Run Discrete Event Simulation Set simulation options Click Run While simulation is running, view stats on events processed per second and amount of RAM used by simulation After simulation completes, check simulation log for errors DES / Open DES Log

60 Modeler Day 1 © copyright 2003 OPNET Technologies, Inc. DES Log Contains errors generated during simulation Contains information about special events during simulation Your code can write to DES log – good way to output debugging information Always check DES log for errors before trusting results