This Paper presents a Priority Based Recovery Scheme (PBRS) improving the utilization of limited resource- i.e. light-paths- which is necessary when recovery mechanism occurred in the IP Over Optical Networks. PBRS is used in the RLG (Recovery Link Group) made by priority number of LP (Light path).
We assumed there are three kinds of LPs by their traffic characteristics Mission-Critical, Best-Effort and Low-priority -in the RLG. When the LP faults are detected, primary LPs classified by the order of traffic priority choose recovery mechanism by their priority number value. In the priority based RLG, Each LP has its own recovery mechanism priority 1 LP (Mission-Critical traffic) use dedicated protection scheme, priority 2 LP (Best-effort traffic) uses preplanned restoration scheme and Priority 3 LP (Low-Priority traffic) uses dynamic restoration scheme. After recovery mechanism is accomplished, new LP Setup information based on the given priority information is transferred to ingress OXC (Optical Cross Connect) for the purpose of making new light path. OXC has structure capable of making new light paths or releasing light paths via signaling control to maintain consistent recovery capability, regardless of fault count, based on priority scheme.
The PBRS has some advantages expanding availability of LPs that is limited resources in the optical network and designing the network that has consistent recovery capability.
In this paper, we also present a Router and OXC structures, LP failure detection mechanism, and signaling procedures that are necessary to adopt PBRS. The performance and effectiveness of PBRS is demonstrated by means of statistical simulations on randomly generated mesh network topology.
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
Optical multicast in a MPL(ambda)S network has not yet to be defined. An MPL(ambda)S network consists of lambda switching devices such as OXC. In this paper, optical multicast using the mixed waveband forwarding within a MPL(ambda)S network is discussed on both dense-mode and sparse-mode. And the OXC capable waveband switching is suggested. Unlike unicast routing, dense-mode multicast routing trees are established in a traffic-driven manner and it is not possible to topologically aggregate such trees, which are rooted at different sources. In sparse-mode multicast, source-specific trees may coexist with a core/shared trees, and it is not possible to assign a common wavelength label to traffic from different sources on a branch of the shared tree. This paper suggests a mixed waveband-forwarding scheme for supporting all two types of multicast (shared tree, source tree) routing trees in a MPL(ambda)S network.