Study On Cross-Domain Flow Allocation Over Multi-Domain FlexE Networks

With the continuous development of the Internet and the gradual expansion of the network,the traditional network architecture has poor scalability and is hard to meet the demand of the dramatically increasing network services.Meanwhile,the traditional single centralized or distributed path computation element(PCE)computes the path required cross-domain service transmission slowly and inefficiently.The Flexible Ethernet(FlexE)can improve the bandwidth access capability of the transmission network.The thesis is oriented to the cross-domain service flow distribution of Flexible Ethernet(FlexE),and addresses the path computation in cross-domain networks.First,the thesis comprehensively analyzes the technical requirements of path computation in cross-domain networks,introduces a SDN/NFV-based multi-domain network model for FlexE networks,and designs a hierarchical cross-domain path computation flow.The path computation unit communication protocol(PCEP)is further extended to support the encoding of FlexE Group so that PCE can control the cross-domain transmission resource allocation.Second,the thesis addresses the design objective of optimal domain sequence of the path computation process,proposes FlexE-combined fitted-circle strategy and linear programming-based multi-commodity flow optimization(MCFO)strategy,analytically introduces the constraints of interdomain link delay and physical channel available number to select the optimal domain sequence.Based on this,considering the path constraints of FlexE,an assignment algorithm for FlexE Client in a FlexE network is proposed to guarantee the quality of service of FlexE Client.Finally,the thesis designs a measurement example of multi-domain transmission network and cross-domain FlexE Client,develops a simulation program for service flow allocation based on Python,compares and analyzes the solving efficiency of the fitted-circle strategy and MCFO strategy.The results show that the fitted-circle strategy performs significantly in small-scale and light-loaded multi-domain networks,while MCFO is more suitable for large-scale and heavy-loaded multi-domain networks.