With sharp development of new application on network, bandwidth has increased up to 10~40 Gbps. It??s very important to take more efficient information processing to fulfill requirements of better services quality. This article focuses on the construction of backbone network based on IP over SDH. By analysis of transmit structure and protocol stack, several key techniques of information processing are pointed. Furthermore a system module designed with FPGA is proposed. The results show that information of different services can be classified in line speed.