It is a trend that the integrated voice, video and data will be transported in the converged IP/MPLS core network. The combined use of the differentiated services (DiffServ) and multiprotocol label switching (MPLS) technologies is envisioned to provide guaranteed quality of service (QoS). However, such a scheme only dictates per hop behavior (PHB) and it does not control the end to end path the traffic is taking. If some link of the path is congested, packets will be dropped and QoS can not be guaranteed. Another attractive application of MPLS is for Traffic Engineering (TE), which sets up end to end routing path before forwarding data. Unfortunately, MPLS TE only reserves resource in one aggregated class, so that it can not provide QoS for differentiated services. MPLS DiffServ-aware TE makes MPLS TE aware of QoS, by combining the functionalities of both DiffServ and TE. In this paper, the QoS performance is analyzed for different type of services including VoIP, Real time Video, and best effort data traffic. The results show that the guaranteed bandwidth service can give better QoS for real time traffic such as VoIP, but worse QoS for the variable video traffic.