In order to meet the requirements of high reliability and low latency in the 5G network environment， and reduce the resource consumption of network bandwidth at the same time， a Service Function Chain （SFC） deployment method based on node comprehensive importance ranking for traffic and reliability optimization was proposed. Firstly， Virtualized Network Function （VNF） was aggregated based on the rate of traffic change， which reduced the deployed physical nodes and improved link reliability. Secondly， node comprehensive importance was defined by the degree， reliability， comprehensive delay and link hop account of the node in order to sort the physical nodes. Then， the VNFs were mapped to the underlying physical nodes in turn. At the same time， by restricting the number of links， the “ping-pong effect” was reduced and the traffic was optimized. Finally， the virtual link was mapped through k-shortest path algorithm to complete the deployment of the entire SFC. Compared with the original aggregation method， the proposed method has the SFC reliability improved by 2%， the end-to-end delay of SFC reduced by 22%， the bandwidth overhead reduced by 29%， and the average long-term revenue-to-cost ratio increased by 16%. Experimental results show that the proposed method can effectively improve the link reliability， reduce end-to-end delay and bandwidth resource consumption， and play a good optimization effect.

To solve the problem of receiver buffer blocking and load unbalance of Concurrent Multipath data Transfer using Stream Control Transmission Protocol (CMT-SCTP) in heterogeneous network environments, an improved round-robin data scheduling algorithm was proposed. The network condition of each path was estimated by the proposed algorithm according to the sender queue information and the congestion status of links. Then the proposed data scheduling algorithm distributed the transmission task to each path based on its network condition, curtailed the queuing time of data chunks in sender buffer and reduced the number of out-of-order data chunks in receiver buffer. Simulation results show that the improved round-robin data scheduling algorithm can effectively enhance the transmission efficiency of CMT-SCTP in a heterogeneous wireless network environment and mitigate the receiver buffer blocking problem. It can also adapt to different network conditions.