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Featured Examples

Example 1: PING (One way Communication)

Figure-1: One way Communication

Steps at Emulation Server

1. Run NetSim in Administrative Mode and create a basic network Scenario in any stack based protocol (Any network except Legacy Networks, Wireless Sensor Network, and Cellular Network) in NetSim. Screenshot of a sample scenario in Internetworks is shown below Figure-2.

Figure-2: Network Topology

• Go to Properties of Link1 and Link2 and set Uplink and Downlink Delay to 5000µs. Click on the Application icon present on the ribbon and set properties.

• In the Application Type select Emulation.

• Select Source and Destination ID according to the network scenario and change the Source and Destination IP address according to the IP address of the real system.

Figure-3: Application properties window

2. Provide the Simulation Time as how long you want the Emulation to be performed. Make sure client system(s) are ready and then click Run Simulation.

Steps at Source PC

• Before running simulation, start pinging the Destination from Source using command “ping <Destination_IP> –t” and note down the time duration.

Figure-4: Before running simulation, total time taking by 1ms

• Follow steps as provided before in “Emulation Set-up: Setting up the NetSim Client”.

• Perform the steps at Emulation Server as provided and simulate. During simulation, ping the destination system. You will notice that the present time duration is higher than the earlier ping results. This is because the network created in NetSim has link propagation delay. Also, Wireshark (if installed) will automatically start capturing the packets as soon as Emulation Server starts simulation.

Figure-5: After running simulation, total time taking by 11ms

(NOTE: In case if no ping messages can be sent from source to destination, disable windows firewall and try again.)

• The impact of the link propagation delay in NetSim Emulator is seen on a real packet.

Example 1: PING (Two-way Communication)

Figure-6: Two-way Communication

In PING (Two-way communication), almost all the steps are same as PING (One way communication), except that in NetSim Emulation server there will be two applications instead of one. One Application will be directed from Source to Destination node, while the other application will be directed from Destination to Source node.

The difference caused in the network behaviour is that in the first case (PING -One way communication), the PING reply packets were not routed via NetSim Emulator. But in the second case (PING -Two-way communication), the PING reply to packets will be routed via NetSim Emulator, thereby the total delay will be approximately 21milliseconds.

Example 2: Video (One way Communication)

Figure-7: Video One-way Communication

Steps at NetSim Emulation Server

1. Run NetSim in Administrative Mode and create a basic network Scenario in any stack-based protocol (Any network except Legacy Networks, Wireless Sensor Network, and Cellular Network) in NetSim. Screenshot of a sample scenario in Internetworks is shown below Figure-8.

Figure-8: Network Topology

• Click on the Application icon present on the ribbon and set properties.

• In the Application Type select Emulation.

• Select Source and Destination ID according to the network scenario and change the Source and Destination IP address according to the IP Address of the real system and click OK.

Figure-9: Application properties window

2. Provide the Simulation Time as how long you want the Emulation to be performed. Make sure client system(s) are ready and then click Run Simulation.

During Simulation you will notice a change in the quality of the video being played in the destination PC. This is because the network created in NetSim has errors / delays etc in the links. The impact of this loss / jitter / delay etc in NetSim Emulator is seen on a real video stream.

Steps at Source PC

1. Follow steps as provided before in “Running Emulation via GUI 🡪 Setting up the NetSim Client”. Then open VLC Media player 🡪 Click Media menu 🡪 Select Stream Option.

2. Click add button then select the video which you want to play.

Figure-10: Select a video using Add option in VLC media

3. Click on Stream Option. Then click next button.

4. Enable the display locally checkbox. Then select the RTP / MPEG Transport Stream from the drop-down list as shown in the below screenshot

Figure-11: Select the RTP / MPEG Transport Stream from the drop-down list in VLC media

5. Click on Add Button. Then enter the Destination IP address in the Address field and enter a stream name (user defined) and click next button.

Figure-12: Enter the Destination IP address in the Address field and enter a stream name (user defined)

6. Select Video –MPEG-2 + MPGA (TS) option from the drop-down list as shown in the below screen shot. Then click next button.

Figure-13: Select Video –MPEG-2 + MPGA (TS) option from the drop-down list

7. Perform all the steps at Emulation Server and then click on Stream button. Also, Wireshark (if installed) will automatically start capturing the packets as soon as Emulation Server starts simulation.

Figure-14: Perform all the steps at Emulation Server and then click on Stream button

Steps at Destination PC

1. Follow steps as provided before in “Running Emulation via GUI–Setting up the NetSim Client”. After performing all the steps at Source PC and NetSim Emulation Server, open VLC Media Player🡪 Click on Toggle Playlist icon as shown in the below screenshot Figure-15.

Figure-15: Select Toggle Playlist icon

Toggle button is circled in red at the bottom of the screen shot

2. Double click on Network Stream (SAP) under local network. Then right click and play on the stream name that appears on the screen.

Figure-16: Double click on Network Stream (SAP) under local network

3. In the streamed video, you will notice a change in the quality of the video being played in the destination PC. Also, Wireshark (if installed) will automatically start capturing the packets as soon as Emulation Server starts simulation.

Figure-17: Change in the quality of the video being played in the destination PC

Example 3: File Transfer using FileZilla (One-way)

Figure-18: File Transfer using FileZilla (One-way communication)

Steps at Destination PC

1. Follow steps as provided before in “Emulation Set-up: Setting up the NetSim Client”. Run FileZilla Server software. Create a group by going to Edit 🡪 Groups 🡪 Select “General” under Page: 🡪 Click Add in Groups 🡪 Give Any Name (Ex: Admin) and click ok.

Figure-19: Give Any Name to group in edit option in FileZilla server

2. Go to Edit 🡪 User 🡪 General 🡪 Click Add in User 🡪 Give Any Name (Ex: User1) and Select Group what you given in Group Setting (In this case, we provide “Admin”) and click ok.

Figure-20: Add name to Users field in FileZilla server

3. In Account Setting, select Enable account and set password and click ok.

Figure-21: Enable account and set password in account setting window

4. Go to Shared folder 🡪 Add Folder to share (EX: FTP_FILES from Desktop) 🡪 Select all the Files and Directories Permissions and set that folder as Home Directory by selecting “Set as Home Dir”. Click OK.

Figure-22: Select all the Files and Directories Permissions and set that folder as Set as Home Dir

Steps at Source PC

Follow steps as provided before in “Emulation Set-up: Setting up the NetSim Client”. Run FileZilla Client software. Enter the Host Name(Server System ip (EX: 192.168.0.133)) and Give the User, Password that we created in Server side and give Port No = 21. Run Emulation server and click Quick Connect. Drag and drop files from Local Site to Remote Site.

Steps at NetSim Emulation Server

1. Run NetSim in Administrative Mode and create a basic network Scenario in any stack-based protocol (Any network except Legacy Networks, Cellular Networks, and Wireless Sensor Networks) in NetSim. A sample scenario in Internetworks is performed as shown with link speed set to 1 Mbps.

Figure-23: Network Topology

• Click on the Application icon present on the ribbon and set properties.

• In the Application Type select Emulation.

• Select Source and Destination ID according to the network scenario and change the Source and Destination IP address according to the IP Address of the real system and click OK.

Figure-24: Application properties window

2. Provide the Simulation Time as how long you want the Emulation to be performed. Make sure client system(s) are ready and then click Run Simulation.

Results: Transfer speed from client without emulation:

Figure-25: Transfer speed from client without emulation

Transfer speed from client with emulation:

Figure-26: Transfer speed from client with emulation

Example 4: Skype (Two way Communication)

Figure-27: Skype Two-way Communication

Steps at NetSim Emulation Server

1. Run NetSim in Administrative Mode and create a basic network Scenario in any stack-based protocol (Any network except Legacy Networks, Wireless Sensor Network, and Cellular Network) in NetSim. Screenshot of a sample scenario in Internetworks is shown below Figure-28.

Figure-28: Network Topology in this experiment

2. Click on the Application icon present on the ribbon and set properties. As it is two-way communication, add and create two applications.

3. In both the Application Type select Emulation.

4. In one Application, select Source ID and Destination ID according to the network scenario and change the Source and Destination IP address according to the IP Address of the real system. In the second application, set the opposite of first application, i.e. Source ID and IP address will be exchanged with Destination ID and IP address. (Refer the IP settings in the screenshot to get a clear picture)

Figure-29: Application properties Window

5. Provide the Simulation Time as how long you want the Emulation to be performed. Make sure client system(s) are ready and then click Run Simulation.

Steps at Source PC

1. Follow steps as provided before in “Emulation Set-up: Setting up the NetSim Client”.

2. Run Skype and make a call to the destination system (Make sure that Skype is running in Destination PC).

3. Wireshark (if installed) will automatically start capturing the packets as soon as Emulation Server starts simulation.

Steps at Destination PC

• Follow steps as provided before in “Emulation Set-up: Setting up the NetSim Client”. After performing all the steps at Source PC and NetSim Emulation Server, open Skype.

• Wireshark (if installed) will automatically start capturing the packets as soon as Emulation Server starts simulation.

Example 5: Using JPerf

JPerf is a graphical front end for the popular network testing tool Iperf. Using JPerf you can quickly test a WAN or LAN connection to determine the maximum network throughput. The test results are automatically graphed and presented in a format that is easy to read. JPerf can also be used to detect packet loss, delay, jitter, and other common network problems.

Figure-30: Jperf Client and server communication

Steps at NetSim Emulation Server

1. Run NetSim in Administrative Mode and create a basic network Scenario in any of the networks except Legacy Networks, Wireless Sensor Network, and Cellular Network. Screenshot of a sample scenario in Internetworks is shown below Figure-31.

• Click on the Application icon present on the ribbon and set properties.

• In the Application Type select Emulation.

• Select Source and Destination ID according to the network scenario and change the Source and Destination IP address according to the IP Address of the real system and click OK.

Figure-32: Application properties window

2. Provide the Simulation Time as per the time for which you want Emulation to be performed. Make sure client system(s) are ready and then click Run Simulation.

Steps at Source PC

Follow steps as provided before in “Emulation Set-up: Setting up the NetSim Client”. Run JPerf and select Client and set Server Address as <Server IP Address>. User can edit the Application Layer options, Transport Layer options and IP Layer options depending on the type of data they want to transmit in the network.

Figure-33: Select Client and setting done as per above screenshot in JPerf

Do not click “Run IPerf” until all the steps at NetSim Emulation Server are done. Also

Wireshark (if installed) will automatically start capturing the packets as soon as Emulation.

Server starts simulation.

Steps at Destination PC

Follow steps as provided before in “Emulation Set-up: Setting up the NetSim Client”. Run JPerf and select Server.

Figure-34: Select Server and setting done as per above screenshot in JPerf

Click on “Run IPerf” after the Source PC starts running JPerf.

Example 6: Simple Military (TDMA) Radio Use Case

Lab Setup: Before starting emulation, ensure that the real traffic that is generated at the NetSim Client (say Ping or Iperf traffic) is routed through NetSim Emulator System. This means the traffic just flows through the system (OS) and doesn't yet flow through NetSim.

Figure-35: Lab set up where by two systems connect to the NetSim emulation server

• The Lab Setup where, Client 1 generates traffic, and Client 2 is the real destination to receive the traffic.

• Route the traffic generated by Client 1 via NetSim Emulation server. This is achieved by configuring static routes in the network. Please refer section 2.2.

Next, we create the scenario in NetSim, and this time run the emulator, whereby the traffic flows through NetSim. The steps to do this are:

• On NetSim Emulation Server, run NetSim in administrative mode and choose TDMA Radio Networks and create a scenario

Figure-36: Select TDMA Radio Networks in NetSim home screen

Figure-37: A simple TDMA radio network is created with two nodes

• Click on the Application icon present on the ribbon and set properties.

• In the Application Type select Emulation.

• Select Source and Destination ID according to the network scenario and change the Source and Destination IP address according to the IP address of the real system.

Figure-38: Application settings

Figure-39: Wireless node parameters to be configured

Next, we change a property and see the effect. For example, change the PHY rate. The parameters that can be varied are:

• Frequency Band: L- Band

• Bandwidth:128KHz

• Data Symbol Rate: 128kBd

• Modulation Tech: QPSK

• Coding Rate: 1/2

• Min Slot Per Device: 0

• Static Route from Source to Destination

Right Click on Wireless node > Properties > Interface Layer > Physical Layer change parameters highlighted in the figure below. Ensure that you perform this in both the nodes since some of the parameter’s scope is local in the Network.

Figure-40: The parameters to be configured in the node’s wireless interface

Steps to Set Static Route in NetSim:

1. Go to Display Settings > Check Device IP

2. Now go to Wireless Node properties->Network_Layer. Enable - Static IP Route ->Click on Configure Static Route IP and set the properties as per the screenshot below and click on Add and then click on OK.

Figure-41: Wizard to configure static route

3. Add appropriate route from Source Node to Destination Node and vice versa

For Source Node:

Figure-42: Static route setting in source node

For Destination Node:

Figure-43: Static route setting in destination node

Provide the Simulation Time as how long you want the Emulation to be performed. Make sure client system(s) are ready and then click Run Simulation.

Now notice the following change in the iperf traffic. Let NetSim Client 1 be the Iperf Client and NetSim Client 2 be iperf server. Then commands at

Iperf Server: iperf.exe -s -u -P 0 -i 1 -p 5001 -f k

Iperf Client: iperf.exe -c 192.168.0.154 -u -P 1 -i 1 -p 5001 -f m -b 1.0M -t 100000 -T 1

Perform the steps at Emulation Server as provided and simulate. During simulation, generate 1 Mbps at iperf client (NetSim Client 1) to NetSim Client 2. You will notice that the even though the iperf client is generating 1Mbps iperf server will be receiving less than 120Kbps. This is because the network created in NetSim has PhyRate (wireless link capacity) set to 120Kbps.

Iperf Client Generating 1 Mbps traffic:

Figure-44: Iperf running in the client

Iperf Server receiving 120Kbps since Phyrate has been set to 120Kbps in NetSim

Figure-45: iperf running at the server showing throughput received

Providing pcap file as input to NetSim Emulator

NetSim has an inbuilt traffic generator (Application) which can be used to model unicast broadcast traffic in the network with support for application types such as CBR, Custom, Voice, Video, FTP, Database, etc. NetSim also allows users to provide pcap file as input to NetSim traffic generator and configure applications using the real IP addresses and port numbers.

Generating a pcap file for NetSim

Any pcap file can be provided as input to NetSim by following the procedure explained here. In this example we are generating a pcap file by running wireshark and generating traffic using ping and saved it as Raw.pcap (while saving please make sure that save as file type must be Wireshark/tcpdump/.. -pcap). Ping is initiated form the Source IP: 192.168.0.154 to the Destination IP: 192.168.0.192. The pcap file will contain all incoming and outgoing packets from the system in which the capture is being done.

Figure-46: Packet captured in Wireshark

Wireshark capture can be stopped after capturing required packets and saved in desired location with a user defined name (.pcap). E.g.: Input_to_NetSim.pcap

PCAP file needs to be edited suitably before providing it as input to NetSim. The "editcap" application in Wireshark installation directory can be used to edit any pcap file to be provided as input to NetSim.

Go to wireshark installation directory [C:Program FilesWireshark]

Figure-47: Installation directory of Wireshark

Open command prompt, and execute the following command:

editcap -C 14 -L -T rawip -F pcap "<File Location where the file is present>/Raw.pcap" "<File Location where the file needs to be saved>/Input_to_NetSim.pcap"

Where,

• -C [offset:]<choplen> chop each packet by <choplen> bytes. Positive values chop at the packet beginning, negative values at the packet end. If an optional offset precedes the length, then the bytes chopped will be offset from that value. Positive offsets are from the packet beginning, negative offsets are from the packet end. You can use this option more than once, allowing up to 2 chopping regions within a packet provided that at least 1 choplen is positive and at least 1 is negative.

• -L adjust the frame (i.e. reported) length when chopping and/or snapping

• -T <encap type> set the output file encapsulation type; default is the same as the input file. An empty "-T" option will list the encapsulation types.

• -F <capture type> set the output file type; default is pcapng. An empty "-F" option will list the file types.

Figure-48: Enter the above command in command prompt

Providing pcap file as input to NetSim

1. Create a system environment Variable with Variable Name as “EMULATOR_INPUT” and value as the path of the pcap file along with the file name (Ex: C:UsersbhatvDesktopNetSimINPUT_TO_NETSIM.pcap).

Figure-49: Create a system environment Variable name and providing input file path as input

2. Start NetSim as administrator. Now create a simple scenario in NetSim. For example, create a scenario in Internetworks with 1 router and 2 wired nodes as shown below. Create an Emulation application by giving the real source and destination IP’s present in the pcap file. In this case we have used the IP addresses 192.168.0.154 and 192.168.0.192 which we have used for generating traffic using PING.

Figure-50: Network Topology in this experiment

3. Run NetSim in administrator mode for Emulator application.

4. Now create a simple scenario in NetSim. For example, create a scenario in Internetworks with 1 router and 2 wired nodes.

5. Create an Emulator application by giving the real source and destination IP’s present in the pcap file.

Figure-51: Application properties Window

• Multiple applications can be configured based on the packets captured. For instance, there can be one more application configured for packets from 192.168.0.192 to 192.168.0.154

• NetSim Emulator will read the packets from pcap file as per the source and destination that we are giving in the application properties.

• After simulation, NetSim results window provides Packet Capture Metrics. Here users can observe 4 different types of log files as explained in section 3.1

• Open Dispatch to Emulator packets, it contains only the packets whose source and destination IP addresses match with the source and destination IP addresses that we have configured.