Network performance of multi-service circuit switched networks: simulational comparison of variants of DAR and RTNR

The use of dynamic routing methods has an important impact on the performance of multi-service networks in overload and failure conditions. The paper describes and compares the performance of variants of reference dynamic routing methods (DAR and RTNR). Two variants of DAR (dynamic alternate routing), resulting from the extension to multi-service networks of the original formulation of the method, are presented. Also, a simplification of the trunk reservation mechanism per traffic class of RTNR (real time network routing) is considered. The major results of extensive experimentation with these variants of the routing methods using a discrete event simulation platform are discussed. The simulation model includes Poisson and Engset type multi-class traffic flows. Conclusions concerning the relative performance of the methods at network level and per traffic class are put forward.