A new framework for reliable transmission in MPLS network based on variable cost functions

Explicit routing and the pre-allocation of network resources are essential to achieve absolute end-to-end QoS guarantees in networks. MPLS (multi protocol label switching) provides a good platform to implement explicit routing and also supports pre-establishment of multiple explicit routes for a source-destination pair. When fault occurs, in order to improve fault tolerance, Switching to a pre-assigned back up path is much faster than determining a new path (e.g by executing a shortest path algorithm), so failure recovery time is much improved, we show that MPLS can achieve reliable explicit routing, by deploying, pre-assigned alternate paths with QoS constraints. All back up paths respect QoS constraints.