The complex data transfer applications, such as the telephony, video on demand and multimedia conferencing, have become a fundamental requirement. The aim of these applications is to accelerate the information transfer as audio and image packets flows format, comparing to other data formats.The architecture of services' differentiation was suggested as a simple solution to provide different quality services for the different types of packets. Hence, the quality service's (QoS) goal is to ensurea regular transfer rate of packets with a high priority ,on one hand, and a preservation of packets that can produce an information distortion on the other hand.In this work, we put forward a protocol that guarantees, firstly, a differentiation of service for the different type of flows, and then, a fair sharing of the bandwidth. This protocol will work in collaboration with the token bucket mechanism.