I would like to plot the TCP congestion window of a node. Currently, I am doing it from the packet trace in NetSim. However, I would prefer to do it in wirehshark since it is the industry standard tool. Can I capture packets sent from a 'virtual' or 'simulated' node in NetSim onto Wireshark? Will it be equivalent to capturing packet from a real node? Will all the fields of the packet be present in the pcap capture file?
Check this link:
https://www.researchgate.net/post/Can_I_capture_packets_in_wireshark_from_a_network_simulator
My best regards.
The link given above by Andrey will explains the UI settings in NetSim to capture packets in wireshark.
This will capture packets at the node where wireshark is enabled.
Yes it is equivalent to capturing packets in a real node since all the packet fields (and payload) is available in the captured packet.
In NetSim, to enable packet capture in Wireshark, Right Click on the device where Wireshark should capture packets. In the properties, go to Global_Properties and set the Wireshark Capture parameter as Online.
Wireshark Capture automatically starts during simulation and displays all the captured packets.
Packets can be filtered by protocol, presence of a field, values of field’s etc. And users can also analyze each of the conversation and can create graphs by selecting them and clicking on “Graph”.
Thank you Andrey Vinajera Zamora and Ashwini Bhat . I have now been able to generate a pcap(Wireshark) capture after running simulations in NetSim. Can you please guide me on how to plot the congestion window in Wireshark?
And also if I want to change some properties of the congestion control algorithm in TCP, where should I make the code changes?
In Wireshark, Go to Statistics Menu -> Conversations. You can analyze each of the conversation and can create graphs by selecting them and clicking on “Graph".
The different types of graphs possible are
1. Round Trip time
2. Throughput
3. Time/Sequence (Stevens)
4. Time/Sequence (tcptrace)
5. Window Scaling
Choose statistic -> TCP Stream Grap -> Window Scaling. This will give you the congestion window
The congestion window algorithm source codes are available in the TCP project folder. It has codes for Tahoe, Reno, New Reno, BIC and CUBIC.
Thank you Ashwini Bhat . I have now been able to plot the TCP congestion window. Can you guide me further on the TCP codes? How can one implement their own congestion control algorithm in NetSim? Are there any examples available?
Sravan, The codes for TCP are available in NetSim-Install-directory/Src/Simulation. Open the NetSim.sln file in Visual Studio and you will be able to see the TCP project. In this the code for the congestion control algorithms is in congestion.c
It is pretty easy to understand. Modify the code per your algorithm and then rebuild and run NetSim
You can also enable this macro for debug purposes
#ifdef _TEST_CONGESTION_
fp = fopen("Congestion.csv","w");
fprintf(fp, "Called For,Time,CWND,ssThres,Flight Size,Ackno,UNA,\n");
fflush(fp);
#endif
- Badges
- Science topic
- Similar topics
- Filing