This paper presents a new model of M2M traffic of wireless sensor networks. Internet of Things traffic is a significant component of modern networks traffic. Such traffic is used today by modern M2M devices. The peculiarity of M2M traffic consists in its generation by a large number of devices. The number of such devices can be many times greater than the number of regular users. The share of this traffic is more than an order of magnitude less than the video traffic. M2M device traffic is poorly understood and much less predictable. Thus, when developing new technologies, it is necessary to focus a lot on this traffic. The paper contains the results of M2M traffic analysis and develops model of M2M traffic. The 3GPP model was chosen as the base model. The analysis of this model is given, and also its modification is offered. This model allows to simulate the traffic at the unlimited time interval. A feature of this model is the stability characteristics of the devices. It allows to evaluate not only the initial attempts to transmit messages, but also attempts caused by reduced service quality. The mathematical description of the model and simulation results are obtained in the research. It describes the traffic of M2M devices and its impact on quality of service in the network. The obtained results can be used to model the traffic of M2M devices and to select their parameters. In addition, algorithms have been developed to control M2M devices during possible overloads.