Nowadays, access network evaluation is being conducted in both directions: high bit rate access development for providing high quality of service and decrease length of cooper wiring in local line networks. It’s paid special attention to the networks, which are based on optical and optoelectronic components. Passive optical network (PON) is an all optical network, which is based on passive optical components only and excludes the conversion of electrical signal into optical form and vice versa. This paper is concerned with the algorithm for calculation of call blocking probability in upstream traffic multiservice model for PON considering the functioning process of optical network units and the principle of wavelength dynamic distribution. These results are used in the blocking probability analysis of the model. © Springer International Publishing Switzerland 2016.