Packets can be collected at various traffic points in the Internet backbone networks, which usually use optical fiber cables for their links. Optical splitters or some other device that replicates one input signal into multiple output signals can be placed at these links to retrieve a copy of data flowing through the backbone network without much effect on the existing network performance. With one side of the splitter connected to a network card of a computer, the time stamp, IP address, and TCP header of each packet passing through the line can be written to the hard drives of the computer by using packet capture software.