A method and system for forecasting telephony traffic trends on a network of a given service provider includes storing local number portability (LNP) record portions in a LNP database. Each LNP record portion contains information regarding a corresponding telephone number having been ported between service providers. First and second images of the LNP database are obtained at first and second times. The first and second images are indicative of all the LNP record portions stored in the LNP database at the first and second times. The images are compared to determine migration of the ported telephone numbers between the service providers over a time period between the first and second times. Movement of telephone traffic on the network of the given service provider after the second time is then forecasted as a function of the determined migration of the ported telephone numbers between the service providers.