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To deliver reliable differentiated services in optical networks, GMPLS requires a set of procedures to provide protection for the traffic carried on the light paths. In this paper we propose a hierarchical path protection mechanism that is simple, scalable, fast, and efficient. We describe in detail our design considerations, the communication of fault information to appropriate forwarding or/and switching elements, and the fault detection protocol. In particular, we propose a new notification protocol for efficient and fast distribution of fault notification messages. A new Hierarchical Path Protection (HPP) improves the utilization of network resources- Label Switched Paths (LSPs) such as Electrical LSP (E-LSP), Lambda-LSP (L-LSP), WaveBand-LSP (WB-LSP), Fiber-LSP (F-LSP), bandwidth etc.- that are necessary when recovery mechanism occurred in the GMPLS networks. The HPP is used in the multiple-layer networks made by priority number of paths. We assume that there are three kinds of priorities on LSPs by their traffic characteristics of multimedia services, real time, mission-critical and best-effort services in the GMPLS networks. When the faults of LSPs are detected, primary LSPs classified by the priority of multimedia traffic choose recovery mechanism according to their priorities. In the priority based LSPs, each LSP has its own recovery mechanism that the LSP of priority 1 (real-time traffic) has the dedicated protection scheme, the LSP of priority 2 (mission-critical traffic) has the preplanned restoration scheme and the LSP of priority 3 (best-effort traffic) has the dynamic restoration scheme. After recovery mechanism is accomplished, the information for setting up on LSP based on the given priority is transferred to the ingress Optical Cross Connect (OXC) for the purpose of making new LSP. The OXC has the structure capable of setting up new LSPs or releasing LSPs via a signaling to maintain the consistent recovery, regardless of fault count, based on the priority scheme. The HPP has some advantages expa
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