Determining, by a first mobility management network element and a second mobility management network element that are ISR associated, that a serving gateway fails, and saving, by the first mobility management network element and the second mobility management network element, a context of a user equipment that the serving gateway serves; receiving, by the first mobility management network element or the second mobility management network element, a trigger, and executing a service restoration process for the user equipment. According to the embodiments of the present invention, the mobility management network element executes a service restoration process, thereby ensuring normal operation of a service.