Patent ID: 8280022

Claim:
A system for selecting a calling party number for an outgoing call at a call center comprising: a memory storing a list comprising one or more called party telephone numbers, each comprising a NPA-NXX, a first data structure configured to associate each NPA-NXX to one of a plurality of areas, a second data structure configured to associate each of the one of the plurality of areas to a corresponding pool of telephone numbers from among a plurality of pools of local telephone numbers, an index value, wherein the index value has a maximum value equal to a number of the telephone numbers in a specific pool and the index value is periodically incremented, decremented, or randomly determined; and a processor configured to receive a replacement data structure comprising replacement local telephone numbers to replace the local telephone numbers in the specific pool of local telephone numbers from among the plurality of pools; retrieve a called party telephone number from the list of one or more called party telephone numbers, use the NPA-NXX of the called party telephone number and the first data structure to determine a designated area associated with the called party telephone number from among the plurality of areas, use the designated area and the second data structure to determine the specific pool of replacement local telephone numbers, the specific pool of replacement local telephone numbers associated with the designated area, use the index value and the specific pool of replacement local telephone numbers to determine the calling party number for the outgoing call, and generate the outgoing call using the calling party number.