Development of communication dispatching tandem exchange;

Analyzing and treating of signaling in tandem PBX;

By analyzing the TOP structure of railway fundamental network,according to the planning and construction principles of fundamental network,this paper brings forward a technical solution for fundamental network that combines the TOP structure of serial loop and tandem star network.

This paper introduces the principles and methods of implementation of whole-network intelligent business of tandem office mode,and probes into the network security and disaster recovery technology.