Fault Tolerance and Load Balancing in QoS Provisioning with Multiple MPLS Paths

The paper presents approaches for fault tolerance and load balancing in QoS provisioning using multiple alternate paths The pro posed multiple QoS path computation algorithm searches for maximally disjoint i e minimally overlapped multiple paths such that the im pact of link node failures becomes signi cantly reduced and the use of multiple paths renders QoS services more robust in unreliable network conditions The algorithm is not limited to nding fully disjoint paths It also exploits partially disjoint paths by carefully selecting and retaining common links in order to produce more options Moreover it o ers the bene ts of load balancing in normal operating conditions by deploying appropriate call allocation methods according to tra c characteristics In all cases all the computed paths must satisfy given multiple QoS con straints Simulation experiments with IP Telephony service illustrate the fault tolerance and load balancing features of the proposed scheme