So I need to simulate Isis2 in ns-3. (I am also to modify Isis2 slightly, wrapping it with some C/C++ code since I need at least a quasi real-time mission-critical behavior)
Since I am far from having any of that implemented it would interesting to know if this is a suitable way of conduct. I need to specifically monitor the performance of the consensus during sporadic wifi (ad hoc) behavior.
Would it make sense to virtualize a machine for each instance of Isis2 and then use the tap bridge( model and analyze the traffic in the ns-3 channel? (I also am to log the events on each instance; composing the various data into a unified presentation)
You need to start by building an Isis2 application program, and this would have to be done using C/CLI or C++/CLI. C++/CLI will be easier because the match with the Isis2 type system is closer. But as I type these words, I'm trying to remember whether Mono actually supports C++/CLI. If there isn't a Mono compiler for C++/CLI, you might be forced to use C# or IronPython. Basically, you have to work with what the compiler will support.
You'll build this and the library on your mono platform and should test it out, which you can do on any Linux system. Once you have it working, that's the thing you'll experiment with on NS/3. Notice that if you work on Windows, you would be able to use C++/CLI (for sure) and then can just make a Windows VM for NS3. So this would mean working on Windows, but not needing to learn C#.
This is because Isis2 is a library for group communication, multicast, file replication and sharing, DHTs and so forth and to access any particular functionality you need an application program to "drive" it. I wouldn't expect performance issues if you follow the recommendations in the video tutorials and the user manual; even for real-time uses the system is probably both fast enough and steady enough in its behavior.
Then yes, I would take a virtual machine with the needed binaries for Mono (Mono is loaded from DLLs so they need to be available at the right virtual file system locations) and your Isis2 test program and run that within NS3. I haven't tried this but don't see any reason it wouldn't work.
Keep in mind that the default timer settings for timeout and retransmission are very slow and tuned for running on Amazon AWS, inside a data center. So once you have this working, but before simulating your wifi setup, you may want to experiment with tuning the system to be more responsive in that setting. I'm thinking that ISIS_DEFAULTTIMEOUT will probably be way too long for you, and the RTDELAY setting may also be too long for you. Amazon AWS is a peculiar environment and what makes Isis2 stable in AWS might not be ideal in a Wifi setting with very different goals... but all of those parameters can be tuned by just setting the desired values in the Environment, which can be done in bash on the line that launches your test program, or using the bash "Export" command.