The method includes following steps: on the gate keeper, sets up limiting level to limit tandem between all replay routes for each relay access user; when user requires tandem between different relay routes, the gate keeper makes control management for the tandem in term of the limiting level of tandem. The invention can smartly set up the right to access different tandem between different relay routes. For example, the user can set up a tandem limiting level that only permits the one way tandem from Shanghai relay gateway to Beijing relay gateway, and doesnt permit the backward tandem. |