想用libusb写个usb to usb的数据传输程序需要了解什么知识？

现在需要写一个软件实现两台电脑间的数据传输，连接通道是usb to usb，买了一根oti 2208nf的usb互联线
libusb本身api用法基本搞清楚了usb_bulk_write也成功了，但usb_bulk_read却不成功读出的数据是USB@&..
是不是usb_bulk_write需要按某种规定的数据格式发数据？
从来没写过usb的驱动或应用，实在不知道缺了哪一块，望指点指点，谢谢！
附上oti 2208nf的说明

The OTi-2208NF is a single chip, cost-effective, and high-performance USB2.0 Mass Storage Class Peripheral controller targeted for applications of data transfer between PCs. The design complies with USB High Speed Specification (480Mb/s), Version 2.0.

The OTi-2208NF has two USB interfaces for connecting two PCs. With stable clock slew-rate control, the controller can reduce the EMI issue.

The controller has one dedicated LED control pin and one optional LED control pin(GPIO). The LED display modes - operation, suspend, and standby, are programmable through the production program provided by Oti. Value-added application software for data transfer, synchronization, and data management is also available.

The Oti-2208NF is suitable for on-motherboard applications, especially for laptop computers. It could be designed as a standalone module in the motherboard and connected to one of the USB 2.0 high speed ports from the south bridge. The operating power of module could be supplied by another PC or laptop when the Oti-2208NF was connected to the USB port of another host through the USB cable. It will not consume any power of the local PC or laptop! Such system design may be good for some computing machines that work with the battery-power.
This controller can operate on Windows Vista, Win XP, and Win2000.

The OTi-2208NF is available in cost-saving 48-pin LQFP (7mm X 7mm) package. Another 64-pin or 100-pin package is also available for extending extra functions.

 

Features

● Mass storage class controller with Universal Serial Bus interface
● USB Specification Compliance
● Conforms to high-speed (480Mb/s) USB Specification, Version 2.0
● Meet bus power specification
● Integrated two USB transceivers
● Stable slew rate, independent of external loading
● Integrated USB Serial Interface Engine (SIE)
● Integrated RISC micro-controller with high-performance RISC architecture for single cycle instruction execution
● 12 MHz external clock
● Integrated regulator for 5/3.3/1.8 V power operation
● Internal power on reset function
● Integrated PLL
● MCU support two serial interfaces I2C and SPI
● Supported OS:
   - Win Vista, Win XP, Win2000, Windows ME without additional driver
   - Windows software application available
      . Go! Bridge
      . Folder Sync
      . Outlook Sync
● Support CD-ROM/CD-RW Auto-Run feature
● Configurable Vendor ID/Product ID (VID/PID)
● Small form factor - standard 48-pin LQFP (7mmX7mm) package