| Recently, Internet has been developed rapidly and was used widely throughout the world, and has gradually become an integrated media facing multi services such as voice, video, data and multimedia application. However, traditional IP network can not provide QoS guarantee to specific service because of its best effort mechanism. L2 fast-switching technology (e.g. ATM) has the simple and effective forwarding algorithm and a set of complete QoS mechanism. When we attempted to combine the advantages of IP and ATM, Multiprotocol Label Switching (MPLS) appeared. This scheme adopt Label Swapping technology like ATM, and do not change current IP routing protocols at the same time. The emergence of MPLS has revolutionary significance to the development of communication network.First, this paper introduces the basic principle, key technology and working flow of MPLS. Then, two important key technologies of MPLS, i.e., Traffic Engineering (TE) and Quality of Service (QoS) guaranty, are deeply researched. We present MPLS framework of realization for IP-TE, and the mechanism through which IP QoS and CoS are guaranteed by MPLS, namely QoS-LSP technology. Furthermore, other management methods of MPLS TE and interoperability between QOS-LSP mechanism and other QOS protocols have been studied and discussed.Since MPLS is up-to-date and developed rapidly, and subject to the experimental environment and methods, we did some functional and performance testing to verify MPLS TE and QoS mechanisms in lab during the study. The MPLS's remarkable technological advantages at these twoaspects were proved through the analysis of data. |
