Thanks Ivan for the information.
D-Link designs there NAS as for there intended use. Network Access Storage, not USB storage. Users should review all information and research specs before buying any NAS. I presume most all other NAS may have the same limitation with the USB port as well. These products are NAS, not USB drives. They are built and designed with Networking access in mind and for mass storage capabilities and based on moving mass data over networks with network performances. USB is slow and can't perform as well as Gb LAN networking. D-Link DNS does very well with networking mass data storage and worked as intended by D-Link. I recommend D-Link DNS anytime. User can make there own decisions based on what products are designed and intended for. not what users think they should be.
Good Luck.