?

I would expect that you would need to use an Ethernet crossover cable, rather than a standard network cable if you were to connect directly without a switch or a router in the middle. These look like normal cables except that Transmit and Receive wires are reversed (so that one ends Transmit becomes the other ends Receive and vice versa). You can buy these cables in several places, or you buy a small dongle that plugs into the RJ45 socket and reverses the wires (so that you can use a standard cable). You can also make one yourself if you have the proper crimper. It could also be the YD7001 automatically adjusts, if it was designed that way.

J. Scott Walton