—In this paper, a traffic aggregation based SIP over MPLS network architecture is proposed to integrate SIP protocol with traffic engineering (TE) enabled MPLS network seamlessly and speed up the SIP call setup. We rely on OPNET simulation to assess the performance of this new network architecture. As a highlighted part, basic design concepts and implementation details of the simulation model are depicted intensively. The simulation results show that traffic aggregation based SIP over MPLS network architecture has satisfying performance in terms of SIP call setup delay, call blocking probability, and bandwidth utility efficiency.