Description

Real-time network applications depend on schedulers to guarantee the quality of service (QoS). Conventional real-time schedulers focus on the timing constraints but are much less effective in satisfying the security requirements. In this paper, we propose an adaptive security-aware scheduling system for packet switched networks using a real-time multi-agent design model. The proposed system combines real-time scheduling with security service enhancement. The scheduling unit uses the differentiated-earliest-deadline-first (Diff-EDF) scheduler and the security enhancement scheme adopts a congestion control mechanism. The required QoS is guaranteed for different types (audio and video) of real-time data flows, while the packet security levels are adaptively enhanced according to the feedbacks from the congestion control module. Compared with the IPsec protocol, the proposed scheme reduces the number of pending packets at the destinations. In implementation, the proposed scheme can overload the priority code point and the virtual-LAN identifier fields of the IEEE 802.1Q frame format, hence eliminating the overhead of the security associations performed by the IPsec protocol.