Systems and methods to monitor and analyze customer premises equipment downtime in a Voice over Internet Protocol service network are disclosed. Example methods for a dynamic host configuration protocol server disclosed herein include assigning a replacement Internet protocol address to a residential gateway, the replacement Internet protocol address to replace a first Internet protocol address assigned to at least one of the residential gateway or customer premises equipment associated with the residential gateway, sending a first address change message to a session border controller, and sending a second address change message to a lost subscriber time server, the first and second address change messages to indicate that the first Internet protocol address has been replaced by the replacement Internet protocol address.