A transient pre-emptor includes a processor configured to detect transients in a communications system. First, a preamble sequence of a frequency package is sent to a frequency offset estimation device so that an initial frequency offset signal amount is obtained and sent to the frequency offset compensation device for compensation. The session controller is further configured to forward an indication of the VoIP registration request and a signaling message to an application server, such that at least a portion of the topology of the communications network beyond the session controller is hidden to the endpoint.