To get access to a Cisco router there are several ways. One is to use the usual RJ45 to DB9 serial cable. But due to the fact the almost all new laptops are not delivered with this interface anymore Cisco ha decided to implement a USB interface to the new devices.
I tested it on a Cisco 2921 router and 3750X switch.
All that was necessary was an USB cable (USB A connector to mini USB B connector) (available with Cisco or any computer store) and the . Cisco USB driver pack.