TwistedSim is a network simulator for Python applications, TwistedSim supports "Code Transparency" which means that TwistedSim user doesn't have to change his application's code in order to interface it with the simulator, rather the simulator injects itself under the hosted applications.

TwistedSim enables the user to simulate his/her code in a reproducible network environment. It also enables the user to simulate an application as if being run by large number of nodes where the user set for each node its own network configuration, this feature is very important especially for P2P systems.

In order for the user to host his Python application under TwistedSim the user needs to write an external piece of code which acts as an application handler for his application (note that the user didn't change anything in his actual application's code), an application handler is just a simple TwistedSim interface that the user implements.

Though that TwistedSim is a generic network simulator however it should be noted that it implements a native support for Twisted based applications (i.e. Twisted users won't need to implement an application handler to host their application on TwistedSim).

The poster session will discus mainly the following:

• Explaining TwistedSim and its features in more details.

• Explain the implementation details of a specific component to an interested attendee.

• Discus the limitations of TwistedSim and how to get around some of them.

• Discus what TwistedSim is evolving to and how an interested person can help.