Abstract: MPLS is a network architecture that ensures data forwarding by using a system of « label » which allows to provide a system based on packet switched service and unifies data transport. The power of MPLS is to offer several applications, for example QOS, TE and VPN etc. The QOS involves ensuring the expected performances for a given traffic network. There are several kinds of performances such as throughput, transmission delay jitter, etc. As for Diffserv model, it consists in gathering the flows classes so as to associate them with predefined QOS. Through this research after defining the quality of service , presenting the specificities of MPLS technologies and their impact on the protocols, we will present a solution to MPLS problem with efficient quality of service based on current protocols and their extension ( LDP, CR- LDP, RSVP, RSVP-TE etc.) Finally, we will present different solutions corresponding to the following models : MPLS, MPLS- DiffServ, MPLS-TE and combination of( MPLS_DiffServ and MPLS-TE).