Embodiments of the present method allow only one serving mobile switching center to connect an incoming call from a communication terminal to a customized ring back tone server when a called mobile terminal moves from an area of a serving mobile switching center to an area of a bordering mobile switching center. Embodiments may have the steps of: passing, by the serving mobile switching center, an indicator that indicates whether customized ring back tone service is already provided for an incoming call to a mobile terminal to all bordering mobile switching centers when intersystem page operation is in effect; saving, upon receiving the indicator by each bordering mobile switching center, the information up for later processing in each bordering mobile switching center; checking, when a respective bordering mobile switching center receives the mobile terminating call, the indicator and checking active customized ring back tone service in a profile of the mobile terminal to determine if a customized ring back tone is to be provided to the communication terminal; and connecting, if the indicator indicates that the customized return ring back tone is not already connected to the communication terminal, to the communication terminal otherwise the respective bordering mobile switching center not connecting the customized ring back tone server again to the communication terminal even if the mobile terminal has customized ring back tone service active and a profile thereof. The system implements the method.