it guru day 1 © copyright 2001 opnet technologies, inc. 2 course outline overview of the product...

IT Guru Day 1

copyright 2001 OPNET Technologies, Inc. 2 Course Outline Overview of the product line What can IT Guru do for you? Documentation IT Guru workflow Creating the network topology Creating traffic Choosing statistics Configuring and running a simulation Viewing results Expanding or modifying the study Publishing

copyright 2001 OPNET Technologies, Inc. 3 Goals of Class Learn mechanics of using IT Guru Learn about every step in the workflow Practice each step with a lab By the end of the day, you will have created a simulation from start to finish and found an optimal solution for a networking problem

copyright 2001 OPNET Technologies, Inc. 4 What is Not Covered This class is an overview it does not go into detail about every feature Methodologies are the focus of Advanced IT Guru take that course next to learn more about how to create simulations efficiently while maintaining accuracy Product modules such as ACE, Flow Analysis, Radio, and NetDoctor are not covered

Overview of the Product Line

copyright 2001 OPNET Technologies, Inc. 6 Corporate Profile In Recognition of Visionary use of Information Technology The SuperQuest Award For Best E-Business Solution At Supercomm Founded in 1986 Publicly Traded (NASDAQ: OPNT) 2000+ Customer Organizations ~75% US, 25% International Intelligent Network Management Solutions Enterprises Service Providers Network Equipment Manufacturers Offices in Bethesda, MD (Headquarters) Santa Clara, CA Boston, MA Dallas, TX Cary, NC Paris, France Oxford, UK

copyright 2001 OPNET Technologies, Inc. 7 Blue Chip Customers Manufacturers Service Providers Enterprises 3Com Corporation Advanced Micro Devices Alcatel Ascom Boeing CableLabs Cisco Systems Comsat Conexant Systems Ensemble Commns Ericsson Fujitsu General Instruments GTE Harris Communications Hewlett Packard Hughes ilotron Intel ITT Lockheed Martin Lucent Technologies Magnavox Marconi Matsushita Microsoft MITEL Motorola NEC Mitsubishi Electric Newbridge Nokia Nortel Onex Panasonic Tech. Philips Qualcomm Raytheon Rockwell Sharp Labs Siemens Sony Sun Microsystems Telcordia Telia Tellabs Tellium Terawave Texas Instruments Thomson Toshiba Tropic Networks TRW Vitesse SemiConductor WirelessHome Zaffire Abbott Labs ABN AMRO Accenture Aerospatiale Atofina Petrochemicals AG Edwards Bank of Oklahoma Booz-Allen & Hamilton CACI Federal Cal Fed Capital One Charles Schwab & Co. Citicorp Compaq Global Services CSC Cummins Engine Co. CVS Pharmacy DaimlerChrysler Dell Computers DHL DirecTV Entergy Enterprise Rent a Car Ernst & Young FBI Federal Reserve Bank Fidelity Investments First American First Citizen First Union National Bank General Dynamics IBM Global Services Ingram Micro Inovant Intermedia Communications Internal Revenue Service Kemper Insurance NASA National Semiconductor NCR Newport News Shipbuilding Oracle Predictive Systems Prudential RR Donnelly SAP Schneider Electric Sears Seattle Times Schlumberger Siebel Systems Spiegel State Street Bank TXU Unisys Visa International VSP AirTouch AT&T AT&T Wireless Belgacom Bell Canada BellSouth British Telecom Cable & Wireless Chunghwa Telecom Compuserve Deutsche Telekom Dolphin Telecom Enron France Telecom Hungarian Telecom Hutchison 3G ITALTEL SpA Indonesia Telecom Infonet Inmarsat Intelsat KDDI Korea Telecom LG TeleCom Network Access Slns Nextel NTT DoCoMo NTT Group Omnitel One 2 One Orange PCS Orbital Sciences Polish Telecom PT Comunicacoes QoS Networks Qwest SBC SK Telecom Sprint SWIFT Swisscom Telekom Austria Telecom Italia Telecom Italia Mobile Teledesic Telefonica Telenor TELUS Telstra UUNET Verizon Vodafone Williams WIND SpA WorldCom

The world's largest event for network design, modeling, and management RSVP for OPNETWORK2002 on Aug 26-30 @ Washington D.C

copyright 2001 OPNET Technologies, Inc. 9 IT Guru: for networking professionals Modeler: for advanced network R&D ServiceProvider Guru: for telecommunications service providers NetBiz: customizable platform for automating network design, provisioning, proposals and analyses MainStation: model, analyze and design multi-vendor, multi-technology networks WDM Guru: optical network design and planning Is IT Guru the right product for you?

copyright 2001 OPNET Technologies, Inc. 10 IT Guru Predicts the performance of enterprise networks Ideal for application deployment, technology migration, SLA compliance, enterprise network planning, and failure studies

copyright 2001 OPNET Technologies, Inc. 11 Products Address Distinct Markets Accelerating Network R&D Intelligent Network Management for Enterprises Intelligent Network Management For Service Providers Enterprises Service Providers Manufacturers Automating Network Design

copyright 2001 OPNET Technologies, Inc. 12 Modeler Design and analysis of networks, evaluation of network technologies, and advanced network R&D Model authoring features used to build and compile models of communications protocols Protocol and device models developed are compatible with other OPNET products

copyright 2001 OPNET Technologies, Inc. 14 MainStation Model, analyze and design multi-vendor, multi-technology networks Comprehensive performance simulation, network cost analysis, survivability and growth analyses

copyright 2001 OPNET Technologies, Inc. 16 Class Format Purpose of the class: To allow attendee to have a hands-on learning experience and introduce many of the features of OPNET. About half lecture, half lab. More lecture at the beginning; this will lay a strong foundation. Interactive; do not hesitate to ask questions. We might not complete all labs in this session; labs may be completed on your own. Note: In the interest of time, some labs contain short simulation runs. Since the data may not have a chance to converge, the students results may not match the results in the manual exactly.

copyright 2001 OPNET Technologies, Inc. 17 Class Format During labs, raise your hand and an assistant will be able to help you. This is not a step-by-step tutorial manual (included in OPNET's documentation is such a tutorial)! Concepts will be taught during lecture, and students will apply them to labs. You may have questions, especially during the labs, and we encourage you to ask.

copyright 2001 OPNET Technologies, Inc. 18 OPNET Products and Services Training Services - Series of hands-on classes IT Guru Introduction Advanced IT Guru Modeler Introduction Advanced Modeler OPNET University Customized classes are available Consulting - Modeling Services Fixed Cost Time and Materials

What Can IT Guru Do For You?

copyright 2001 OPNET Technologies, Inc. 20 Examples of Problems Solved IT Guru can be used to: Identify problems Increasing traffic loads by 20% causes unacceptable FTP response times If the Chicago router fails, the Des Moines router becomes overloaded The link between Seattle and Portland averages 10% utilization Pinpoint causes The FTP server is not fast enough More traffic than expected is being routed through Des Moines Test solutions Where is the best location to put a new server? Which route configuration will give the best performance?

copyright 2001 OPNET Technologies, Inc. 21 1 oz Prevention = 1 lb Cure Perhaps most important, anticipate bottlenecks before they become problems How will migrating to an ATM backbone affect response times? Will the network be able to handle this new application? How will moving an office affect its performance? Where are potential bottlenecks in my network? How will changing routing protocols affect my network? What will be the effect of adding 1,000 new users? How can I be assured that re-segmenting my network and adding OSPF areas will better performance? Being able to test changing conditions beforehand allows you to proactively predict, test, and implement solutions

copyright 2001 OPNET Technologies, Inc. 22 Application Deployments Capture a live trace of an application on a network Deploy in a model to understand application response times over various internet connection speeds What effect will the application deployment have on existing applications? Size links; size servers to accommodate the new load How will this application perform if we deploy over an ATM backbone vs. Frame Relay?

copyright 2001 OPNET Technologies, Inc. 25 Understanding Protocol Behavior Problem: Large file transfers too slow Upgrading from T1 to T3 is costly, and more importantly, does not help Cause: TCP is throttling throughput Solution: Modify TCP window size Cost: $0

copyright 2001 OPNET Technologies, Inc. 27 Failure Analysis How long will it take routes to converge if we fail a router? How will response times be affected? How much traffic will need to be re-routed due to a failed link?

copyright 2001 OPNET Technologies, Inc. 28 Take-Away: What Can IT Guru Do For You? IT Guru proactively predicts performance of a model of your network to aid Application Deployments Capacity Planning Technology Migration Understanding Protocol Behavior Identifying Network Configuration Errors Failure Analysis IT Guru is easy to use

Documentation

copyright 2001 OPNET Technologies, Inc. 30 Places to Find Help View the online manuals by choosing Help / Online Documentation Access model help by right-clicking object icons in the object palette or by right-clicking objects in the Project workspace and selecting View Node Description Access attribute help via the Details button in many dialog boxes Show context-sensitive help by choosing Help / Whats This then clicking on an object Show Tool Tips by placing your cursor over any object and waiting for a brief description of that object

IT Guru Workflow

copyright 2001 OPNET Technologies, Inc. 34 Agenda: IT Guru Workflow Projects and scenarios Understand what questions to answer Build model to answer questions Follow any/all workflows using the same set of models Application Workflow DES Workflow Flow Analysis Workflow NetDoctor Workflow

copyright 2001 OPNET Technologies, Inc. 35 Application Workflow - Optimize Application Performance with ACE Visualize Behavior Capture application traces Interpret trace data Visualize n-tier transaction dynamics Identify dependencies of message flows Display content of payload (e.g. Oracle SQL) Diagnose Performance Summarize application delays into their respective components Diagnose potential performance bottlenecks Collect application performance statistics Explore Solutions Validate compliance to service level agreements Optimize infrastructure to withstand growth in application usage Evaluate impact of change on the performance of mission-critical applications

copyright 2001 OPNET Technologies, Inc. 36 IT Guru Workflow Create/Import Topology/Configuration Use NetDoctor for configuration/topology/rules validation Create Traffic Use Flow Analysis for capacity planning, routing, failure/recovery studies Choose Statistics Run Simulation View Results Duplicate or Create New Scenario Publish Results DES Workflow NetDoctor Workflow Flow Analysis Workflow

copyright 2001 OPNET Technologies, Inc. 37 Projects and Scenarios IT Guru uses a Project/Scenario approach to modeling networks A Project is network study Involves the need to answer or understand a problem or issue with the network infrastructure Will provide a collection of data for appropriate decision making in the resolution of these questions or issues A collection of related network scenarios in which each explores a different aspect All projects contain at least one scenario A Scenario is a single instance of a network Typically, a scenario presents a unique configuration, i.e., topology, protocols, applications, traffic, and simulation settings Will show statistics and impact of what if scenarios as applied to the infrastructure

copyright 2001 OPNET Technologies, Inc. 38 Example of Projects and Scenarios PROJECT What is the impact of adding new application, 100 users SCENARIO - 1SCENARIO - 2SCENARIO 3..... Baseline Topology and traffic to represent current load on network of all required applications and other activity. Collect statistics of current utilizations of links, servers and other points of interest Add New Application Add new users of application where required. Gather statistics of impact on application response times, link utilizations, server utilizations, other statistics as required. What ifs Based on results of scenario-2, this scenario and additional scenarios would test different what if (potential) solutions. Results of this scenario (#3) may create additional questions that need to be answered in subsequent scenarios.

copyright 2001 OPNET Technologies, Inc. 39 Understand What Questions To Answer Build a model to answer particular questions How to model large networks (large numbers of nodes and/or large amounts of traffic)? Need to represent topology and traffic using aggregation techniques Still maintain fidelity of the model Small topology results may feed subsequent larger simulations First scenario might model a single LAN using high fidelity discrete event simulation These results may be used to aggregating traffic for large network simulation

copyright 2001 OPNET Technologies, Inc. 40 Create Topology Import May not be necessary for your particular study often modeling critical path of traffic is sufficient Import from HP Network Node Manager Lucent NavisCore Tivoli NetView Router Configuration Files ATM Text Files XML Files Manual Configuration drag and drop network devices from palettes of objects Cut / copy / paste Rapid Configuration of typical topologies

copyright 2001 OPNET Technologies, Inc. 41 Create Traffic Hybrid Simulation - analytic and explicit traffic modeled in same simulation Analytic Simulates fast Models bulk load of traffic by informing network elements of volumes of traffic flowing through Explicit Extremely accurate Takes longer to simulate Models packet by packet entire application and each protocol throughout network

copyright 2001 OPNET Technologies, Inc. 42 Choose Statistics Hundreds of possible statistics Establish which statistics to collect to answer questions Types Applications: e.g. Response Time, Traffic Sent/Received Links: e.g. Delay, Throughput, Utilization Protocols: e.g. TCP Retransmissions, Ethernet Collisions Can group common statistics into reports for easy selection

copyright 2001 OPNET Technologies, Inc. 44 View Results Graphs display results from set of statistics chosen Display each statistic separately or together Compare results from different scenarios Apply filters to data to generate PDFs, averages, etc. Export data to text/spreadsheet Animation allows visualization of graphs being drawn, as well as packet and node movement

copyright 2001 OPNET Technologies, Inc. 45 Duplicate or Create New Scenario What if we Changed access link speeds to the backbone? Upgraded servers? Added 4,000 new users? How would our network/application perform under the changed condition? Duplicate Scenario Keep your exiting results Duplicate the scenario, make changes, and re-run the simulation Study multiple configurations Compare results between multiple scenarios New Scenario - Results from one scenario might be used to feed an entirely different topology

copyright 2001 OPNET Technologies, Inc. 46 Publish Results Automatically generates web reports of Entire topology Results ACE Analysis Send images directly to printer Export topology to Bitmap, HTML,Visio, Spreadsheet, XML

copyright 2001 OPNET Technologies, Inc. 47 Take-Away: IT Guru Workflow Create/Import Topology/Configuration Use NetDoctor for configuration/topology/rules validation Create Traffic Use Flow Analysis for capacity planning, routing, failure/recovery studies Choose Statistics Run Simulation View Results Duplicate or Create New Scenario Publish Results DES Workflow NetDoctor Workflow Flow Analysis Workflow

Creating the Network Topology

copyright 2001 OPNET Technologies, Inc. 49 Agenda: Creating the Network Topology Choosing the correct components Choosing the correct background Choosing the correct method Configuring attributes Verifying links

copyright 2001 OPNET Technologies, Inc. 51 Object Palettes Object palettes can be configured to display a group of related network objects Change palettes by selecting a model list from the pull-down menu The utilities palette contains special objects that help create multi-tiered application profiles, configure PVCs, track memory usage, and fail / recover nodes

copyright 2001 OPNET Technologies, Inc. 52 Model Libraries Available Standard Model Library Essential models that support the majority of OPNET modeling users Vendor Model Library Extensive library of pre-built vendor device models Specialized model library Models of interest to more focused communities within the OPNET user community These models correspond to emerging or vendor-specific technologies Available on a fee/license basis Example specialized models Circuit-switched IP Multicasting MPLS Server Models PNNI UMTS DOCSIS

copyright 2001 OPNET Technologies, Inc. 53 Model Architecture Underlying each of the IT Guru standard models is a full protocol stack client/server model Each of the protocols has been modeled individually to simulate exactly the specified behavior of that protocol The high fidelity of the IT Guru protocol models is ensured by thorough testing Instructor Demo: Modeler demonstration illustrating model hierarchy

copyright 2001 OPNET Technologies, Inc. 54 Standard Models: Naming Convention IT Gurus standard model suite uses a specific naming convention for its standard node models: _ _ is an abbreviation that specifies a particular protocol that is supported within the model. The variable n represents the number of protocol interfaces within that model is an abbreviation that indicates the general function of the node, e.g., gateway, workstation, server indicates the level of derivation of the model.

copyright 2001 OPNET Technologies, Inc. 55 Model Naming Convention (cont.) Levels of derivation ( value) adv: advanced model. All node attributes are visible and editable, and attribute values are set to their defaults. in t: intermediate model. Attributes that are unlikely to be changed are hidden and typical values are applied to the visible attributes. Models with no value for modifier are derived from intermediate models. Additional attributes are hidden and only attributes needed for parametric studies are visible. Example: ethernet2_slip8_gtwy_adv This model represents a gateway with 2 Ethernet and 8 slip interfaces. Because it is an advanced model, all the models attributes are visible and configurable.

copyright 2001 OPNET Technologies, Inc. 57 Vendor Models In addition to our standard models, OPNET contains models for the following vendors: 3Com Ascend Avici Bay Networks Cabletron Cisco Systems Fore Systems Foundry Hewlett Packard Juniper Lucent Newbridge Nortel Sun

copyright 2001 OPNET Technologies, Inc. 58 Vendor Models: Naming Convention Naming convention for vendor models: _ _ _ Example: CS_4000_3s_e6_fr2_sl2_tr2 This model represents a Cisco Systems 4000 Router with 3 slots, 6 Ethernet, 2 Frame Relay, 2 SL-IP, and 2 Token Ring ports You can also view a description of the node by: Right-clicking on the node in the Object Palette Right-clicking on the node in the workspace and selecting View Node Description

copyright 2001 OPNET Technologies, Inc. 59 Link Models: Naming Convention An appropriate link must be chosen to match interfaces on connected devices Data rate, protocol, and number of available interfaces are the requirements that must be met Link models naming convention: _ Example: 10BaseT_adv Modifier value is same as for node models

copyright 2001 OPNET Technologies, Inc. 60 Creating New Devices Although IT Guru includes hundreds of standard and vendor devices, you may need a custom model Device Creator Design a model based on function, supported protocols, and number of interfaces Derive New Models Change the default attributes of an existing model Save with a new name

copyright 2001 OPNET Technologies, Inc. 61 Derive new models IT Guru allows the user to select an existing standard or vendor model and derive a new model based on the parent models specifications. The user can then alter the attributes of the newly derived model to reflect a device that will be used in the network simulation.

copyright 2001 OPNET Technologies, Inc. 63 Advantages of deriving models Makes it easy for the user to configure and integrate models for specialized needs. Allows the user to benefit from past work by basing new, specialized models on previously created ones. Gives the user 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. Cant change interfaces or underlying protocols; can change attribute values.

copyright 2001 OPNET Technologies, Inc. 64 Device Creator Provides the ability to create automatically a particular device with a specific configuration. Typical devices include routers, switches, hubs, bridges, vendor specific devices, multihomed hosts, and LAN models. The Device Creator may be invoked through the Network pull-down menu.

copyright 2001 OPNET Technologies, Inc. 65 Advantages of Device Creator Allows users to select any number of interfaces and protocols that a device will need to support. Gives the users complete flexibility in modeling in that they are not limited to only the models provided in ITDG. Provides the user with more control over memory efficiency to possibly reduce simulation run-time.

copyright 2001 OPNET Technologies, Inc. 66 Organizing Models - Object Palettes An object palette is a graphical dialog box that displays a group of node and link models. Object palettes can be customized to contain only the nodes and links that the user requires. As the next section will show, there are several different methods for customizing palettes.

copyright 2001 OPNET Technologies, Inc. 69 Object Attributes Subnet, node, and link objects 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

copyright 2001 OPNET Technologies, Inc. 71 Why Use LAN Models? LAN models are a powerful mechanism for abstracting complex local area networks that may contain multiple nodes with the same configurations LAN models allow users to display various local area networks and avoid a needlessly cluttered and unwieldy workspace LAN models use less memory LAN models generate fewer simulation events allowing simulations to run faster These models represent the same network

copyright 2001 OPNET Technologies, Inc. 72 Cloud Models Clouds 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 set up PVCs through the network

copyright 2001 OPNET Technologies, Inc. 73 Choosing the Correct Background Maps Put network scale in context Ensure correct distance between nodes Startup Wizard Used to set network size and location Subnets Grid Properties Specify range of subnet

copyright 2001 OPNET Technologies, Inc. 74 Map Backgrounds IT Guru includes several maps that can be loaded as backgrounds Map backgrounds provide a physical context for model specification Models are more easily interpreted when set in a proper geographical context Distance between nodes affects delay, so must be calculated accurately TIFF, MIFF (MapInfo), and GEOTIFF image maps can be imported as well, as shown below Image of part of Chicago

copyright 2001 OPNET Technologies, Inc. 76 Getting Started The Startup Wizard is used to set context for a new scenario quickly The Startup Wizard sets: Project and scenario name Initial topology Network scale Background map Technologies

copyright 2001 OPNET Technologies, Inc. 77 Subnets Subnets are a powerful mechanism for breaking down a systems complexity through abstraction Subnets also allow distances between network segments to be modeled with more accuracy

copyright 2001 OPNET Technologies, Inc. 78 A subnetwork abstracts network components specified within it into a single object. Subnetworks: Represent identical constructs in an actual network. Have no behavioral aspects, but simplify representation of large networks. May be stationary or mobile. Subnets 3 Subnet Types

copyright 2001 OPNET Technologies, Inc. 80 Why Use Subnets? Subnet coordinate systems allow placement of objects according to a geographic location while the positions of the nodes of the subnet are relative to an origin. Consider a network of 3 buildings in 3 different cities. Realistic placement of the subnets requires a coordinate system in degrees, but when modeling the actual location of the individual devices, it is prudent to change the subnet grid system to meters.

copyright 2001 OPNET Technologies, Inc. 81 Grid Properties WAN modeling requires large network scale such as degrees Latitude and Longitude LAN modeling requires smaller scale such as meters or feet View / Edit Grid Properties allows you to set the scale within a subnet

copyright 2001 OPNET Technologies, Inc. 82 Methods of Creating a Topology You have a choice of building or importing a network topology To build a topology: Choose the correct node models Position the nodes Set node attributes Choose links and connect nodes with links To import a topology: Use third party software to discover the topology Import into IT Guru Fine-tune the network and verify that correct models were imported

copyright 2001 OPNET Technologies, Inc. 83 Zoom In / Zoom Out The zoom button on the toolbar zooms to a rectangle The unzoom button returns to the previous zoom You can zoom in and out by right-clicking on the workspace If you background map disappears, you may have zoomed in too far hit the unzoom button City names are now visible

copyright 2001 OPNET Technologies, Inc. 84 Threshold Attribute The threshold attribute of a node model affects its display characteristics at different zoom levels. If the threshold value is higher than the current resolution of the map, the node will be displayed with a miniaturized icon. This attribute ensures that large network diagrams do not become cluttered with icons at higher resolution levels.

copyright 2001 OPNET Technologies, Inc. 85 Thresholds (cont.) Consider this WAN in Europe. Map resolution: 80 pixels/degree Object thresholds: 10 At this resolution, we are able to discern between the different nodes. Map resolution: 15 pixels/degree Object thresholds: 10 When we zoom out and resolution decreases, our diagram becomes unreadable and unwieldy. Note that these two pictures represent the same network model.

copyright 2001 OPNET Technologies, Inc. 86 Thresholds (cont.) Note that often it will be a case of trial and error for a user to determine a threshold level that is suitable for a specific model. The resolution of the map of Europe in the picture below is 15 pixels per degree. The user must determine an appropriate threshold level. In this case, a threshold level of 40 will give the user a comfortable buffer when changing the magnification levels of the map.

copyright 2001 OPNET Technologies, Inc. 87 Provides users the ability to add rectangles, circles, lines and text to models to enhance their appearance. This method is an effective way to graphically illustrate and document the changes made to a model. Does not affect simulations. Use Edit pull down menu to open Annotation dialog box. Annotations have attributes that configure their appearance. Annotations can be hidden. Annotation Palette

copyright 2001 OPNET Technologies, Inc. 88 Object Selection Methods Select the object before performing the following operations: Changing the attribute values for a group of objects Copying (ctrl+c), Cutting (ctrl+x), and Pasting (ctrl+v) objects Left-click each object to select it, shift+left-click to select multiple objects Drag a selection box around the objects to be selected. Only objects completely enclosed by the box will be selected. Right-click an object and choose Select Similar Nodes from the pull- down menu to select all nodes of the same model Edit / Select Objects allows you to define your own criteria for which objects are selected

copyright 2001 OPNET Technologies, Inc. 89 Rapid Configuration Rapid configuration allows you to quickly build topologies of any size. Available topologies include: Bus; Mesh, Full or Randomized; Ring; Star; Tree; Unconnected Net Dialog boxes allow you to control the number of nodes, the node and link models used, how nodes will be arranged, and node locations within the workspace

copyright 2001 OPNET Technologies, Inc. 90 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 Xs

copyright 2001 OPNET Technologies, Inc. 91 Take-Aways: Creating the Network Topology Object Palettes contain node and link models Right-click on nodes to get more information about them Topologies can be created by hand or imported IT Guru contains features that simplify building the topology

Creating Traffic

copyright 2001 OPNET Technologies, Inc. 94 Agenda: Creating traffic Types of traffic Explicit: packet-by-packet transfer, with each transfer being modeled as a discrete event Background: modeled analytically, doesnt generate as many discrete events, models the network delay experienced by explicit traffic Methods of importing traffic Using the profile and application utility objects to model application traffic Using ACE to import application traffic

copyright 2001 OPNET Technologies, Inc. 95 Types of Traffic Explicit Applications imported through ACE Pre-defined applications Background traffic Device/Link Load Traffic Conversation Pair Matrix Traffic Tradeoff: explicit traffic gives more detailed results, while background traffic makes simulation run faster Methodology: model most network traffic as background traffic, explicitly model several conversations between nodes

copyright 2001 OPNET Technologies, Inc. 96 Explicit Traffic: Pre-defined Applications IT Guru provides a set of pre-defined applications that are configurable through attributes of the Application Config node The pre-defined applications model the behavior of common networked applications listed below: Database Email File transfer File Print Telnet session Video Conferencing Voice over IP call Web browsing

copyright 2001 OPNET Technologies, Inc. 97 Explicit Traffic: Application Traffic Setup Step 1: Application Config Place an Application Configuration node (from the utility palette) in the network Edit Attributes and edit the Applications Definitions attribute This step defines the Applications and levels of use for each Step 2: Profile Config Place a Profile Configuration node in the network Edit attributes and edit the Profile Configuration attribute Each profile you create represents a user. Assign applications to each user. Step 3: Configure clients Edit attributes of workstations, edit the Application: Supported Profiles attribute Assign a profile (created in Step 2) to each client Step 4: Configure servers Each application in use in the network needs a server to support it Edit Attributes of the servers and change the Application: Supported Service attribute

copyright 2001 OPNET Technologies, Inc. 98 Explicit Traffic: Client/Server Example To represent a person using email and downloading files: Add entries for email and FTP in the Application Config node. Define the level of use or use a predefined level. Define a user in the Profile Config node that uses the email and FTP applications you just configured Set the client to support the user profile you just created Set the server to support the email and FTP applications

copyright 2001 OPNET Technologies, Inc. 103 Application Modeling Techniques Explicit (discrete event) modeling & simulation Layer-by-layer Node-by-node Extremely accurate, but time consuming Analytical prediction Algorithms / equations Quick, but less accurate Hybrid simulation

copyright 2001 OPNET Technologies, Inc. 105 Profiles Profiles can be used to represent: Individual user behavior Traffic generated by a group of users Profile properties Name Start time, Duration Repeatability (Serial/Concurrent) Concurrent Profiles Profile Serial Profiles

copyright 2001 OPNET Technologies, Inc. 112 Example Applications Custom Application Name Description Database E-mail FTP HTTP Print Remote Login Voice Video Conferencing Generic/customizable application Data entry/query application E-mail application File transfer protocol application Web-browsing modeling Print job modeling Telnet application modeling Client-to-client voice application modeling Client-to-client video application modeling

copyright 2001 OPNET Technologies, Inc. 115 Hypertext Transfer Protocol Hypertext Transfer Protocol (HTTP) is an application model supporting server-based web browsing interactions The sequence of client-server interactions is between exactly two nodes Server selection for requesting a page or an object is configurable

copyright 2001 OPNET Technologies, Inc. 119 Task Characteristics Client Application Server Database Server 4096 bytes Each Response: 1000 bytes Request: 9920 bytes Response: 300 bytes Delay: 0.1 seconds Delay: 5 seconds Response Time per Request: 0.8 seconds Time between Responses: 0.5 second Time Delay: 0.4 seconds

copyright 2001 OPNET Technologies, Inc. 121 Task Attributes Phase Name Start Phase After (Specifies dependency) Source (Symbolic) Destination (Symbolic) Source->Dest Traffic Dest->Source Traffic REQ/RESP Pattern End Phase When (Specifies dependency) Transport Connection

copyright 2001 OPNET Technologies, Inc. 127 Server Configuration Supporting the application service Specifying the processing speed and overhead Specifying the selection weight Configuring CPU parameters Specifying the number of resources Specifying the task contention mode Specifying the multi-tasking performance table Specifying the processing speed multiplier Server Address

copyright 2001 OPNET Technologies, Inc. 131 Server Computation Computing processing time for a task Apply the processing speed multiplier If (Task Contention Mode == Simulate Contention) Scale processing time based on the number of contending tasks and the multi- tasking table Apply server background utilization

copyright 2001 OPNET Technologies, Inc. 133 Resolving Sources and Destinations Destination preferences Resolve symbolic destinations to real destinations Specify a choice of destinations with a selection weight Source preferences Identify independent sources within the task description table Specify the source preferences

copyright 2001 OPNET Technologies, Inc. 134 Destination Preferences Specifies the immediate destinations in the application sequence Should be set on all nodes that are sources and have to talk to a destination Can contain a set of destinations. In this case, destination selection will be based on the selection weight

copyright 2001 OPNET Technologies, Inc. 135 Explicit Traffic: Application Traffic Setup For more information on setting up these applications, refer to the methodology paper entitled Configuring Applications and Profiles You can find this paper by choosing Help / Online Documentation / Modeling Methodologies / Methodologies and Case Studies

copyright 2001 OPNET Technologies, Inc. 136 Background Traffic: Device/Link Loads You can represent traffic loads on a network as utilization levels on devices links Link load is an attribute of each link, and is expressed as a percentage of the bandwidth that is utilized Discrete packets that traverse the link are delayed based on the background load on that link You can specify a direction or bi-directional loads You can vary the link load over the course of the simulation Device loads represent other demands on device CPUs

copyright 2001 OPNET Technologies, Inc. 137 Device and Link Loads Description Time-varying utilization levels on devices and links Represents aggregate traffic levels Simulation technique Hybrid simulation

copyright 2001 OPNET Technologies, Inc. 138 Device and Link Loads (cont.) Advantages Very fast Interacts with explicit applications and conversation pair traffic Disadvantages Does not contain information about sources and destinations Not suited for failure studies

copyright 2001 OPNET Technologies, Inc. 139 Device and Link Loads (cont.) Representation in OPNET Import from traffic management tools Manually define traffic When to use Represent a baseline or background load for traffic of less interest Configuration helpers Background Utilization attributes on servers, routers, and links Interfaces to Concord Network Health, InfoVista, MRTG, and text files

copyright 2001 OPNET Technologies, Inc. 140 Background Traffic: Conversation Pairs Specify the following: Source node Destination node Time interval Number of bits and packets Tracer packets inform links and nodes of the volume of traffic carried Routing protocols within the network determine which links the traffic uses If the source or destination node is deleted, the traffic is ignored If the source or destination node is moved, traffic is rerouted accordingly

copyright 2001 OPNET Technologies, Inc. 141 Conversation Pair Traffic Representation in OPNET Import from traffic management tools Manually create and edit When to use Represent background traffic flows Model large volumes of aggregate traffic Configuration helpers Conversation Pair Browser Interfaces to Agilent NetMetrix, Cisco Netflow, NetScout, and spreadsheets Instructor demonstration

copyright 2001 OPNET Technologies, Inc. 142 Conversation Pair Traffic Description Traffic between a source and destination Volume in bits/sec and packets/sec Propagated using tracer packets Simulation technique Hybrid simulation Flow Analysis Micro-simulation Advantages Fast - large traffic volumes can be simulated quickly Disadvantages Represents aggregate traffic, not specific applications

copyright 2001 OPNET Technologies, Inc. 143 Tracer Packets Propagated through network based on routing protocols Contain traffic volume information Used in calculating utilizations, throughputs, and queuing delays Sent at each time interval in a conversation pair profile time interval

copyright 2001 OPNET Technologies, Inc. 144 Importing Background Traffic Conversation Pairs can be imported from: Agilent NetMetrix Cisco NetFlow Netscout Spreadsheet Link loads can be imported from: Concord NetworkHealth MRTG Text files After the import, some sources or destinations may not be recognized. You will be prompted to assign this traffic to a node, then re-import the traffic.

copyright 2001 OPNET Technologies, Inc. 145 Traffic Browser The traffic browser allows you to view Conversation Pair traffic between any two nodes in the network You can also edit and scale traffic as needed

copyright 2001 OPNET Technologies, Inc. 146 Traffic Modeling Methodology XXApplication Analysis XXPVC Sizing XXVoIP/Video XFailure Analysis XXProtocol Performance XXCapacity Planning Device/Link Loads Conversation Pairs Explicit Traffic Type of Study Traffic Type Selected traffic type depends on Purpose of study Specific questions you wish to answer

copyright 2001 OPNET Technologies, Inc. 147 Other Traffic Modeling Approaches ICMP traffic Assures connectivity Records per hop and round-trip latencies Routing-only studies Computation of routes Records convergence times for failure conditions ATM call-only mode Records call setup latencies Call admission control MPLS LSPs Computation of dynamic LSP routes Records convergence times for failure conditions

copyright 2001 OPNET Technologies, Inc. 148 Take-Aways: Creating Traffic IT Guru allows you to use any combination of the traffic types Explicitly modeled traffic takes longer to simulate, but provides more detailed information Traffic that exists on the network but is not the focus of the study should be modeled as background traffic For more information about importing explicit traffic through the ACE module, take one of our ACE classes

Choosing Statistics

copyright 2001 OPNET Technologies, Inc. 152 Typical Statistics Application specific : FTP Download response time HTTP Page response time Link specific : Queuing delay Utilization Protocol specific : Ethernet Delay ATM Cell Delay

copyright 2001 OPNET Technologies, Inc. 153 Types of Statistics Node or link statistics are collected from individual objects. They allow the user to analyze performance of specific nodes or links (a single hubs Ethernet delay, for example). Scenario-wide node or link statistics are collected from all relevant objects in a network. They allow the user to easily monitor the performance of all objects of a specific type. This is equivalent of choosing results for each object (each link, for example) in a scenario. Global statistics are collected from the entire network. They represent results that apply to the network as a whole (such as FTP Response Time) and let you analyze aspects of the networks overall performance. Service Level Agreements can be defined for any type of statistic.

copyright 2001 OPNET Technologies, Inc. 154 Service Level Agreement (SLA) SLAs allow you to make sure statistics comply with preset criteria This example shows compliance if a Database Application Response Time is below one second, 95% of the time

copyright 2001 OPNET Technologies, Inc. 155 Choosing Statistics Because there are so many possible statistics to collect, the data files would quickly grow past practical limits if IT Guru recorded them all Select specific results that will answer your questions

copyright 2001 OPNET Technologies, Inc. 156 Statistic Attributes Statistics, like nodes and links, have attributes. Right clicking on a statistic while in the Choose Results dialog box presents a menu of statistic attributes. Statistic attributes include: Record Statistic Animation Change Collection Modes Statistic Description Change Draw Style

copyright 2001 OPNET Technologies, Inc. 157 Descriptions of Statistics To obtain complete definitions of statistics, right-click on the statistic in the Choose Results window and select Statistic Description.

copyright 2001 OPNET Technologies, Inc. 158 Statistic Collection Modes There are three types of statistic collection modes: Normal 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, the user 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.)

copyright 2001 OPNET Technologies, Inc. 159 Understanding Statistics Output should be sanity-checked for accuracy and robustness: Does all output make sense? Can it be justified? Does the model behave appropriately? One technique: predict output first, then compare predicted to actual output Is the model operating in steady state? Expect initial transient behavior, converging to steady state Look for rising averages, increasing queue lengths, or other output that is still varying. This might mean that the model is not in steady state

copyright 2001 OPNET Technologies, Inc. 160 Choosing Individual Statistics To choose Global or Scenario-Wide Node or Link statistics, right click anywhere on the Project Workspace and select Choose Individual Statistics, or choose Simulation / Choose Individual Statistics For Object Statistics, right click on the object of interest and select Choose Individual Statistics

copyright 2001 OPNET Technologies, Inc. 161 Choosing Reports An easy method for defining groups of statistics is to choose an already defined report. From the Simulation / Choose Reports menu item, select reports to be collected You can define your own report from Simulation / Define Report Template

copyright 2001 OPNET Technologies, Inc. 162 Defining a Service Level Agreement Under Simulation / Expert Service Prediction, select Define Service Level Agreement Press Clear Select a statistic Select compliance criteria (threshold and percentage of compliance) Select Bucket Duration Repeat steps for additional statistics Press Save and name the SLA

copyright 2001 OPNET Technologies, Inc. 163 Choosing Service Level Agreements After defining an SLA, you must choose it to collect results Under Simulation / Expert Service Prediction, select Choose Service Level Agreement Select the SLAs for this scenario Once you define an SLA, you can apply it to other scenarios and other projects

copyright 2001 OPNET Technologies, Inc. 164 Take-Aways: Choosing Statistics Choose statistics that will answer your questions about the network Also choose statistics to ensure that your results are valid If you see increasing queue lengths or response times, run a longer simulation 15 minutes vs. 1 hour

Configuring and Running A Simulation

copyright 2001 OPNET Technologies, Inc. 167 Configuring Simulations Users can also set simulation attributes from the Simulation menu, Configure Simulation. Configuring Simulation Name Description Duration Values Per Statistic Number of values to be collected for each statistic. SeedRandom number generation seed. Values for the simulation attributes relevant to the network model being simulated. Right-click the name of an attribute for a description of it. Simulation Attributes Duration of simulation, in simulated time. Generate Web Report If checked, the simulation will produce a web report for the results.

copyright 2001 OPNET Technologies, Inc. 168 Running a Simulation The simulation window shows the progress of simulation and error messages. You can also view messages from the command prompt. During simulations, the elapsed time bar monitors the status of the simulation. This bar appears after 1,000,000 events. Progress: Simulation time elapsed and number of events processed Time: Real time elapsed and remaining Simulation Log: Number of entries present in the simulation log

copyright 2001 OPNET Technologies, Inc. 169 Simulation Log Always check the simulation log after running a simulation: Results / Open Simulation Log Simulation log contains errors and warnings Click on the message field to view details about the message

Viewing Results

copyright 2001 OPNET Technologies, Inc. 174 Results can be displayed easily by: - Selecting View Results from the Results Menu. - Right-clicking the Project workspace and selecting from the pop-up menu - Selecting the View Results button on the tool bar The View Results dialog box allows the user to select the results to display - Note: This is similar to choosing individual statistics except only the statistics you choose to collect will be available The Show button in the View Results dialog box displays a graph of the selected statistics How to View Results

copyright 2001 OPNET Technologies, Inc. 175 Viewing Results Multiple panels can be open at the same time. Each panel can contain one or more traces that graphically depict data either Overlaid or Stacked.

copyright 2001 OPNET Technologies, Inc. 176 Viewing Results Mathematical filters can be applied to results. As Is represents raw data (no filter applied). Plot the filtered trace in its own panel, or add the trace to an existing panel. Often, the average filter is applied to a statistic to plot a running sample mean of the raw as is data.

copyright 2001 OPNET Technologies, Inc. 178 Viewing Results Configure the appearance of graphs for a presentation Right-clicking on the graph itself lets you edit the graph properties. Draw style Color Grid properties Parameter labels Confidence intervals

copyright 2001 OPNET Technologies, Inc. 179 Viewing Results Right-clicking on the gray border around the graph allows you to edit the panel properties. Panel title Background color Horizontal axes and labels

copyright 2001 OPNET Technologies, Inc. 180 Identifying Bottlenecks Typical procedure for identifying the bottlenecks in application performance studies: 1) Choose the application performance, server performance, link queuing delay and link utilization statistics. 2) Run a simulation and observe the application performance. 3) If the performance is not acceptable, check the server utilization and task processing time. This way you will find if the server is being over-utilized. 4) If server is not the problem, then check the link queuing delay and link utilization to see if the links are over-utilized. NOTE : Use Find Top Results utility to easily identify the bottlenecks in the above procedure.

copyright 2001 OPNET Technologies, Inc. 181 Find Top Results After collecting scenario-wide node or link statistics, use Results / Find Top Results to find the bottlenecks Find Top Results shows the highest or lowest values for a statistic Example: find the links with the highest utilization

copyright 2001 OPNET Technologies, Inc. 182 Generating Web Reports Web Reports containing data and statistic graphics can be created after a simulation has run The reports are saved as a series of HTML pages

copyright 2001 OPNET Technologies, Inc. 183 Why Use Web Reports? Web Reports give the IT Guru user a common interface with non-IT Guru users Reports are automatically generated and present data in a manner that is easy to use, navigate, and interpret Reports include a simple text summary consisting of information about SLA violations, and most utilized links, for example Reports are not editable within IT Guru

copyright 2001 OPNET Technologies, Inc. 184 How to Generate Web Reports Web reports can be generated by one of two methods: Before running a simulation, check the option in the Configure Simulation dialog box. After running a simulation, select Results / Statistic Report / Generate Web Report Web Reports take time to generate due to the many graphic files that must be created.

copyright 2001 OPNET Technologies, Inc. 185 Take-Aways: Viewing Results Results can be viewed within IT Guru or exported Right-click on the graph to change view options such as draw style Use Find Top Results to quickly sort scenario-wide node or link statistics Web reports make it easier to navigate through results and share your findings

copyright 2001 OPNET Technologies, Inc. 186 Lab: Reviewing Results Lab #4 View results you collected If your results look drastically different from those in the lab manual, check the simulation log and ask for assistance

Expanding or Modifying The Study

copyright 2001 OPNET Technologies, Inc. 188 Agenda: Expanding or Modifying the Study Projects and Scenarios Modeling multiple scenarios Duplicating and managing scenarios Comparing results among multiple scenarios

copyright 2001 OPNET Technologies, Inc. 189 Projects and Scenarios A Project is a collection of simulations of one network Within a project, create multiple scenarios Each scenario represents one instance of a network Example: Within a project, you can make a baseline scenario, then double the traffic in a new scenario, then add a server to handle the extra traffic in a third scenario

copyright 2001 OPNET Technologies, Inc. 190 Why Use Scenarios? Multiple scenarios allow you to test possible solutions and proposed changes in your network Within a project, you can compare the results from several scenarios on one graph

copyright 2001 OPNET Technologies, Inc. 191 Duplicating an existing scenario and then making changes provides a mechanism for easily comparing network configurations Duplicating scenarios also duplicates the results that were chosen and the simulation configuration To duplicate a scenario, select Scenarios / Duplicate Scenario and name the new scenario Duplicating the Scenario

copyright 2001 OPNET Technologies, Inc. 192 Compare the Results The Compare Results feature allows the user to combine statistics from different scenarios in the same graph. Results from different scenarios can easily be compared by: Select Results / Compare Results Right-click the workspace and select from the pop-up menu Right-click an object and select from the pop-up menu (this option compares results only from statistics collected at this object) Upon selecting the results in one scenario, Comparing Results automatically selects and presents the corresponding results from all other scenarios.

copyright 2001 OPNET Technologies, Inc. 193 Take-Aways: Expanding the Study Every time you make a change to your simulation, duplicate the scenario and change the new scenario Dont change too many variables between scenarios, so you will know why your results changed Use multiple scenarios to find the optimal solution to a problem or to compare different expansion scenarios

copyright 2001 OPNET Technologies, Inc. 194 Lab: Expanding the Study Lab #5 Create two new scenarios to find a solution Upgrade the links and compare the results If your results dont match the ones in the lab book, check the simulation log and ask for help Question: Which links should Lansing upgrade to?

Publishing

copyright 2001 OPNET Technologies, Inc. 197 Locations of Publishing Options To export a topology, choose Topology / Export Topology Bitmap HTML Visio Spreadsheet XML To export Conversation Pairs, choose Traffic / Export Conversation Pairs / To Spreadsheet For printing options, look under the File menu Print Print all subnets Print graphs

copyright 2001 OPNET Technologies, Inc. 198 Publishing Results After building a model, running simulations, and analyzing results, you will often have to report your findings to others It is important to organize, document, and archive the evolution and results of a continually-changing model

copyright 2001 OPNET Technologies, Inc. 202 Exporting to Spreadsheet Exporting your network to a spreadsheet will provide a network summary that includes the type and number of links and nodes in your network model, and financial cost information Helpful for cost-benefit analysis

copyright 2001 OPNET Technologies, Inc. 203 Take-Aways: Publishing Explore the publishing options when you have gathered some data Hot keys: On Windows machines, Alt-Print Screen copies the active window to clipboard so it can be pasted elsewhere with Ctrl-V In IT Guru, Ctrl-T lets you save the active window as a bitmap

copyright 2001 OPNET Technologies, Inc. 204 Edit Preferences Edit / Preferences allows you to change your environment options Important preferences: mod_dirs browser_prog opnet_dir opnet_user_home traffic_archive_dir Instructor Demo

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