On the basis of a brief analysis of a MPOA simulation system, the method how to accomplish the edge device in the simulation system is described.

In order to improve the security of Intranet, application boundary security devices must be set.

First,according to some conclusions of graph theory,the power grid was analyzed,and the graph description of power grid and the definition of edge equipment and point equipment were formed,Then,with the aim of database search and power grid graph construction,the hierarchical structure of database was formed,and the correspondent searching hierarchy and several derivative tables were defined.

The Research of VPN-Supporting Edge-Device;