A novel AF+ service for VoIP applications over a Diff-Serv/MPLS network

A Diff-Serv/MPLS network provides three service classes, including EF, AF, and BE classes. All of these conventional differentiated services in the Diff-Serv/MPLS network only provide one EF-class service, one AF-class service, or one BF-class service to a group of VoIP users individually. We propose a novel AF⁺ service model for VoIP applications over a Diff-Serv/MPLS network. The AF⁺ service model has the advantages of EF-class service and AF-class service simultaneously. We discuss the alternative issues of QoS, provisioned bandwidth utilization and call blocking rate concerning the AF⁺ service model. Our numerical results are useful for VoIP users and network manager to contract SLA and plan network resource distribution.