The aim of this tutorial is to present an overview of conformance testing methods for SDL systems. These methods can be classified into two main groups: those whose intent is the totally automated test generation from the SDL system specification and those that provide interactive test generation methods. We present some of the more representative methods illustrating their application by a common example. This example, the Inres protocol and service, will facilitate the comparison of the methods with respect to SDL and test notations, restrictions on the language, results of the application to the protocol and the tools supporting the methods.