This chapter describes the debugging facilities that OPNET Modeler provides and shows how to debug OPNET models with different techniques. This chapter assumes that the reader understands general debugging concepts, such as call stack, breakpoint, trace and watch, etc.

Debugging facilities in OPNET Modeler

OPNET Modeler provides two levels of debugging capability: object-level debugging and source-level debugging. In object-level debugging, object refers to an OPNET simulation entity like packet, event, process, etc. The object-level debugging process follows the order in which discrete events are scheduled; therefore, it is normally used when you want to track the simulation on an event-by-event basis and track and inspect the simulation objects associated with these events. Object-level debugging reflects the internal logic of discrete event simulation. In source-level debugging, source refers to the simulation source code. The source-level debugging process follows the execution of source code; therefore, it is suitable if you want to track and watch the value of variables and inspect the details of your code. The object-level debugging technique is specific for debugging event-based simulation programs, and the sourcelevel debugging technique is for debugging general software programs. In practice, it is advisable to combine both debugging techniques in order to produce more reliable models.

An object-level debugger is integrated with OPNET Modeler itself. It is called OPNET Simulation Debugger (ODB).