This paper presents a process-algebraic interpretation of the Layered Queueing Network model. The semantics of layered multi-class servers, resource contention, multiplicity of threads and processors are mapped into a model described in the stochastic process algebra PEPA. The accuracy of the translation is validated through a case study of a distributed computer system and the numerical results are used to discuss the relative strengths and weaknesses of the different forms of analysis available in both approaches, i.e., simulation, mean-value analysis, and differential approximation.