1. A method to determine a clock time difference between a first terminal and a second terminal, the method comprising: sending a first Internet Protocol packet from the first terminal to the second terminal, the packet having a time stamp indicating the time at which it was sent from the first terminal; receiving a second Internet Protocol packet at the first terminal from the second terminal, the packet having a time stamp indicating the time at which it was sent from the second terminal; comparing the time stamp of the second packet and an arrival time at the first terminal to determine an inbound latency; comparing the determined inbound latency to the stored bias; setting the stored bias to the determined inbound latency if the stored bias is less than the determined inbound latency; and determining a clock time difference at the second terminal using the stored bias.