Described embodiments provide an IP-aware modem, such as for use in an IP-aware facsimile machine, operable with an IP packet network. The IP-aware modem has voice-band data engine that receives packets from the packet network, converts data in the packets to PCM samples, stores the samples as PCM sample frames in a buffer for further processing by the modem, and determines for each PCM sample frame whether or not during the conversion one or more packets were missing. An equalizer or timing recovery element in the modem adapts using the PCM sample frames and suspends the adaptation for the time period of each PCM sample frame converted without the one or more missing packets. Similarly, searches of the PCM sample frames for certain modem synchronization signals are skipped when, during the search, the searched PCM sample frame was converted without the one or more missing packets.