Combining formal description techniques (FDTs) with performance evaluation (PE) is a requirement known from the 'single-specification/multiple-techniques' approach associated with the protocol engineering vision. The approach presented here assumes that a formally defined open systems interconnection (OSI) communication protocol can be syntactically transformed to a form suitable to a performance evaluation tool, and afterwards enhanced by implementation-dependence information on the protocol's resource requirements. Such a module, describing functional and performance behavior of the protocol, can then be embedded in a framework which allows its performance evaluation. This framework comprises an OSI-service provider as a transportation medium, processors providing computing services, and means for communication with the adjacent upper layer by use of associated input and output buffers. The present approach uses concepts from the performance evaluation tool HIT. Its applicability to OSI-communication architectures is sketched by means of the PE-modeling language HI-SLANG and the FD-language SDL.>

The authors describe a computational approach for modeling and analyzing modern communication systems based on numerical methods for Markov chains. Advanced direct and iterative procedures for the calculation of the stationary distribution of a homogeneous discrete- or continuous-time Markov chain with finite state space are presented. They are implemented in a convenient software tool called MACOM for interactive modeling and performance evaluation of communication systems. MACOM provides the user with a predefined markovian model world describing modern telecommunication networks with adaptive routing schemes and advanced congestion-control mechanisms. The versatility of these algorithms is illustrated by their application to Markovian queuing models derived from telecommunications networks.>