This Recommendation provides general principles and methods for dimensioning B-ISDNs from the call and connection level perspective. A network modelling technique for dimensioning and call and connection level traffic controls such as traffic routing and bandwidth reservation are described. Call demand types that are taken into account for network dimensioning considering available B‑ISDN signalling capabilities are presented. Principles of network dimensioning methods are described and several example methods for computing end-to-end GOS (i.e. call/connection blocking probabilities) are provided.