Real-time capability analysis for switch industrial Ethernet traffic priority-based

In order to realize real-time communication over fast Ethernet in industrial application, one must be able to bound the medium access time within an acceptable limit. But the multiple access nature of Ethernet makes it impossible to guarantee a deterministic medium access time. In this paper, we introduce the IEEE 802.1p queuing feature in switches, and propose a mixed traffic scheduling policy (MTSP) for the lay 2 switches in Ethernet. MTSP adopts different policy for different real-time requirements frames. The objective is mainly to study the worst-case response time for real-time periodic frames and the mean response time for time critical aperiodic frames by setting the appropriate frames priority to meet the industrial application.