Network Middleware Design for Bridging Legacy Infrastructures and NGN

Session-based QoS control mechanism is a key characteristic in next generation networks (NGN). However, the session-based QoS control defined in NGN standardizations is not designed for layer 2 infrastructures, but for border gateway function (BGF) at IP edge. To achieve QoS assurance for NGN services, end-to-end network resource management, including layer 2 access and metro networks, is required. Although the BGF function needs to be introduced at IP edge, legacy infrastructures must be utilized especially for access and metro networks. Incorporating those widely deployed legacy infrastructures into session-based QoS control mechanisms is expected. However, differences in user-flow identification of NGN and resource identification required for managing legacy infrastructures induce gaps blocking integration to the unified session-based infrastructure. This paper proposes to use a network middleware for bridging NGN control frameworks and legacy infrastructures. With the multiple service oriented architecture (SOA) chain, the network middleware distributedly coordinates middleware element managing each network segments, and harmonizes differences of resource description and control procedures in NGN and legacy infrastructures. The network middleware enables to maintain coherent QoS policy for the end-to-end route of the session-based services throughout the heterogeneous and multi-layer infrastructures.