Artalejo Rodríguez, Jesús ManuelMartín Apaolaza, Níriam2023-06-202023-06-202005-09-010096-300310.1016/j.amc.2004.09.038https://hdl.handle.net/20.500.14352/50014The authors thank the support received from the research project BFM2002-02189. N.M. Apaolaza was supported by a grant (‘Formación de Investigadores’) awarded by the Basque Government.Multi-server retrial queues are widely used to model stochastically many telephone systems and computer networks. This paper studies the distribution of the time needed to reach a certain level of congestion, i.e., a given number of customers in the retrial group. We present a detailed algorithmic analysis which includes the computation of the time to reach a critical number of customers (continuous descriptor), the number of customers served during such a time (discrete descriptor) and the corresponding moments for both queueing performance measuresengjournal articlehttp://www.sciencedirect.com/science/article/pii/S0096300304006320http://www.sciencedirect.comrestricted access519.8Multi-server retrial queueFirst passage timeNumber of customers servedMomentsNumerical inversionInvestigación operativa (Matemáticas)1207 Investigación Operativa