MANAGEMENT OF CALLING NAME DELIVERY IN TELEPHONE NETWORKS PROVIDING FOR TELEPHONE NUMBER PORTABILITY

A system and a method for managing calling name (CNAM) queries in a plurality of telephone networks including a plurality of subscribers each assigned a telephone number in a predetermined number series associated with a particular switch in one of the telephone networks, wherein at least one of the number series is a portable number series including telephone numbers assigned by one network but connected to another network. According to the present invention, if the calling party number (CgPN) belongs to a portable number series, gapping will be applied to CNAM queries containing either portable telephone numbers associated with a location routing number (LRN) identifying the switch and network to which the CgPN is connected, or non-portable telephone numbers belonging to the same number series as the LRN. On the other hand, if the CgPN does not belong to a portable number series, gapping will be applied to CNAM queries containing telephone numbers belonging to the same number series as the CgPN.