ATM traffic is specific in comparison with the traffic in other networks. We model telephone, e-mail, ftp, low speed video and HDTV traffic sources. We also apply on-off model for voice and video sources and data sources. Usually AAL2-4 present the decomposition technology of traffic stream into cells for voice and video traffic, and AAL5- for elastic traffic.
Some traffic sources generate cells with deterministic rates. The lengths of calls are exponentially distributed. The mean duration of the HDTV session is one hour and a half. The duration of the low speed video call is the same as the duration of the voice call. We assume that it is used for videotelephone service. The length of the burst and the pause  are exponentially distributed with varied mean values. The assumption that these sources generate cells with deterministic rate makes the simulation process easier. The results are approximate and aim to evaluate the planning parameters of the modified PUSHOUT in worst case scenario.
Figures 2 shows the case of data traffic sources where the packets length and burst level is determed by apriory information about traffic in Internet backbone .