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.