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.

The new-type, large-capacity tandem office may not only further optimize the structure of network, (increase) the security of the network, and make architecture of network to become more clear and more (rational) but also enhance the service ability of network.

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.