00962nas a2200157   4500000000100000008004100001260005000042100002400092700001200116700001200128700002000140700002400160245008900184300001400273520051700287       2014                            d  bSpringer International Publishing Switzerland1 aTadeusz Czachórski1 aT. Nycz1 aM. Nycz1 aFerhan Pekergin1 aTadeusz Czachórski00aTraffic Engineering: Erlang and Engset Models Revisited with Diffusion Approximation  a249–2563 aClassical Erlang and Engset formulae determining the availability of channels, loss probability, and characteristics of overflow traffic are still use in telecommunications. Moreover, they are also interesting for traffic management in mobile networks and in Internet. They are based on the assumption of Poisson flows and exponentially distributed time of connections. By means of diffusion approximation queuing models, we extend these results to the case of general distributions and transient state analysis.