Research On Real-time Transmission Technology Based On P4

Internet technology is changing with each passing day,and the types of business applications in the network are also constantly enriching,many of which have very strict requirements on the real-time nature of network transmission.Therefore,how to provide end-to-end real-time transmission services has always been a research hotspot.The drawbacks of the traditional network architecture's poor flexibility have led to the lack of applicability of existing solutions on this issue.Softwaredefined networking(SDN),a new type of network architecture,increases the flexibility and expandability of the network by separating the data plane and the control plane.As a data-oriented programming language that was born in SDN,P4 is further developed.Improve the programmability and flexibility of SDN.Therefore,the use of P4 technology to solve real-time transmission problems has a lot of room.This thesis has conducted research on the problem of using the data plane programmability provided by P4 to ensure real-time transmission.The main work is as follows:(1)In view of the problem that the current priority scheduling method in SDN is not fine-grained with data flow as the scheduling unit,this thesis proposes a priority scheduling method based on elapsed time and queue delay based on the data packet as the scheduling unit.This method uses P4 technology to implant time information in the header of the data packet,and the switch dynamically adjusts the priority according to the elapsed time of each data packet or the accumulated queue delay to perform queue scheduling to ensure the transmission delay.(2)Regarding the problem that there may still be packets with higher delay after random scheduling is adopted,this thesis proposes a rerouting scheduling method based on elapsed time and queue delay.In this thesis,Yen 's algorithm calculates a shorter path than the main path as a backup path,and reroutes the packets with higher delay in the data flow to the backup path at the deviation point switch to make up for it.This thesis validates the above method in an experimental environment.The experimental results show that this priority scheduling method can provide more fine-grained transmission delay control and has a self-reliance than the existing data flow-based scheduling method in SDN.This rerouting scheduling method can further compensate for higher-latency data packets on the basis of priority scheduling.