Transcript Slide 1
Mobile Networks Introduction to Opnet [email protected] Opnet Workflow • Project Editor Create Network Models Choose Statistics Run Simulation View and Analyze Results Opnet’s editors • Network Models ▫ Represent data networks ▫ Run simulations on network • Node Models ▫ Model devices in the network Process Node Network • Process Models ▫ Represent communication protocols, CPUs, queuing systems Network model – Project Editor Project Editor Workspace Node model – Node editor Process model – Process Editor • Finite state machines (FSM) • States and transitions coded in C or C++ And many more editors • • • • • • • Link editor Path editor Packet format editor Probe editor Simulation sequence editor Modulation curve editor Antenna pattern editor, etc…. Projects and Scenarios • Project-and-Scenario approach to modeling network ▫ Project: collection of related network scenarios. ▫ Scenario: is a single instance of the network. Typically, a scenario represents a unique configuration of the network. The Project/Scenario Workflow • Create Project • Create Baseline Scenario ▫ ▫ ▫ ▫ Import or create topology Import or create traffic Choose results Run simulation, view results • Duplicate Scenario ▫ Make changes ▫ Re-run simulation ▫ Compare results Iterate Object Hierarchy • Subnets: represent various network objects in a single component (may contain various LAN, node and link models) • LAN: a local area network abstracted as a single node • Nodes: represent servers, switches, gateways, workstations, or any other physical device • Links: represent the physical link between nodes Organizing Models – Object Palettes • An object palette is a graphical dialog box that displays a group of nodes and link models • Object palettes can be customized to contain only the nodes and links that we need Create Network Models Choose Statistics Run Simulation View and Analyze Results 1) Create the network New project New scenario -> Startup Wizard Topology Rapid Configuration: Star Choose switch Choose wkst (30 stations) Size = office network, 100 x 100 m Object Palette: Choose server Choose link between server and switch (10BaseT) 2) Create the traffic Object Palette: Application configuration (database access) Profile definition Create Network Models Choose Statistics Run Simulation View and Analyze Results 3) Choose statistics Object statistic (server): SERVER LOAD (bps) Global statistic : ETHERNET DELAY (sec) 4) Simulation Configure simulation Time = 0.5 h Seed • We’ll do the small internetwork example in the lab • Important concepts to remember: ▫ Project Editor => to create a network ▫ Node Editor => to model network equipment ▫ Process Editor => to model modules (functions) of the network equipment ▫ Object Palette => a collection of node models ▫ Project = {scenario 1, scenario 2, …..} Process Node Network Simple Client-Server Network • simple example of OPNET IT Guru to demonstrate the basic operations in creating and simulation a model • Start a new project: File->New...->Project. Give a useful name to the project and scenario (e.g. ProjectDemoClientServer). • Follow the dialog boxes, selecting the following options: ▫ ▫ ▫ ▫ Initial Topology: Create Empty Scenario Network Scale: Office Size: 100m by 100m Model Family: ethernet • The office area will be created and the Object Palette opened. Place the following objects in the network: Application Config ▫ ▫ ▫ ▫ Profile Config ethernet_wkstn (will be our client) ethernet_server (will be our server) ethernet16_switch (a 16 port switch to connect our client and server) ▫ 100BaseT links (connect the client to switch and switch to server) • Give the objects meaningful names by right-click and select Set Name. E.g. Client, Switch, Server, Applications, Profiles. • In the Application Definition object (now called Applications), right-click and select Edit Attributes • Select Application Definitions and set the rows to 1 • For Row 0, give the application a name (such as Web) • In the Description attribute, for HTTP, select Image Browsing Press Ok to close the attributes for the Applications. • Edit attributes for the Profiles, add a new profile with name Web User For the Web User profile, add a new application (set rows to 1) • Select the Web application Press Ok to close the attributes for the Profiles. • Right-click on the Server and select Edit Attributes Set Application: Supported Services to All, and then press Ok • Right-click on the Client and select Edit Attributes Under Application: Supported Profiles add a new row and select the Web User profile, then press Ok • Right-click on the Client and select Choose Individual Statistics Select all items under Client HTTP (they will have green ticks after you select them) • Repeat the above two steps for the Server and Switch, however select the statistics Server HTTP for the Server and Switch for the Switch. • From the main menu select Simulation->Choose Individual Statistics... Under Global Statistics, select all items under HTTP and Ethernet, and then press Ok • From the main menu select Simulation->Configure Discrete Event Simulation... Press the Run button. • Your simulation will take several seconds to execute, finally ending with a message showing the Beginning simulation and time and Simulation Completed Collating Results. • Press the Close button. From the main menu select Results->View Results... Select the following three statistics: ▫ Object Statistics->Office Network->Client->Client HTTP- >Traffic Sent (bytes/sec) ▫ Object Statistics->Office Network->Client->Client HTTP>Traffic Received (bytes/sec) ▫ Object Statistics->Office Network->Client->Client HTTP>Page Response Time (seconds) • Press the Show button • After looking at the results (you can right-click in the results window to make changes), return to the View Results window Click on the As Is option and select instead average, then press Show again. • Close both of the plot panels - select Hide for each. • Close the View Results window. Lab Task • From the main menu select Scenarios>Duplicate Scenario... and select a name such as Client2_Server • Add a new client (you can use copy and paste) so you now have Client1 and Client2 From the main menu select Results->Delete All Panels • Choose the same statistics for Client2 as in the previous scenario, run a simulation and view the results again. • Compare the page response time for Client1 and Client2.