Bugs as features

Being exposed to well-written code is a valuable experience for students—especially when the code is larger or more complex than they are currently capable of writing. In addition to the mechanics of a particular computation, students learn organization and documentation skills, and general concepts illustrated by the specific program. However, to obtain these benefits, students must thoroughly familiarize themselves with the code. This paper describes recent successes using software bugs as a means to force familiarization with network protocol code. The bugs become tools by which the students learn the inner workings of network protocols. As a side benefit, the approach provides a concrete basis for the discussion of debugging approaches and techniques. The technique is appropriate for any course involving programming, and is especially good for upper-level courses like networks, operating systems, and parallel and distributed programming, where difficult concepts can be illustrated via sample programs.