00975nas a2200169   4500000000100000000000100001008004100002260005000043100002400093700001200117700001200129700002000141700002400161245008900185300001400274520051700288       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.