Data Transfer Rates RNDIS vs Belcarra USBLAN for Windows

Measured in MegaBytes per second (MB/s) the graph illustrates gadget CDC-ECM protocol data transfer speed vs. Microsoft's RNDIS protocol using three simple web-related network tests all done with Linux-line tools, on an Overo Gumstix, or on the PC using the Cygwin tools to give a Linux-like environment (see

  • wget (OUT) -- using wget on the device to retrieve a large file.  The traffic measured is in the OUT direction. Output (file retrieved) is discarded.
  • wget (IN) -- using wget on the PC to retrieve a large file. Output is discarded
  • wget OUT- bidirectional
  • wget IN - bidirectional
  • combination of the previous 2

Microsoft's RNDIS vs. Belcarra's USBLAN for Windows - Deployment Costs

RNDIS is Microsoft's solution for providing a networking over USB solution using their proprietary RNDIS protocol.
USBLAN for Windows is Belcarra’s solution for providing a networking over USB solutions using the industry standard protocols CDC-ECM, CDC-EEM and CDC-NCM.
While there are no licensing costs associated with the use of Microsoft’s RNDIS driver this does not mean that the actual cost of deploying a commercial product will be less when RNDIS is implemented.

The Total Cost of Deployment for a USB device using a network over USB solution is composed of multiple items:
  • cost development of the device side protocol support 
  • cost development and testing of the Windows Installation kit 
  • cost of setting up Windows Logo Kit test setup 
  • cost of doing Windows Logo Kit testing 
  • opportunity costs associated with delays while developing the installation kit 
Device Side Implementation Costs
Also support for RNDIS is limited to Windows based systems on the host side. This means that the device must still support another standard (such as CDC-ECM) for compatibility to Linux or Macintosh hosts.

Windows Logo Kit Testing Setup
Windows Logo Kit testing requires:
  • Server 2008 system to run DTM Studio 

Microsoft's RNDIS vs Belcarra's USBLAN for Windows

Zero install solution is a myth
Regardless of protocol (RNDIS or CDC-ECM) you will need to have an INF file somewhere on your Windows system. This INF file can be installed seamlessly from Windows Update (the driver repository part of Windows Update), or it can be copied onto the system by the end user as part of a driver install package. The process is actually identical in both cases. In one case Windows Plug-n-Play support is looking for and downloading the driver installation kit and using it directly while in the other the user downloads the driver installation kit and tells Windows Plug-n-Play where the kit is unpacked.

Whether the RNDIS / USBLAN for Windows driver is from an OEM website download, from a CD, or from Windows Update, the contents of the driver installation kit will be almost identical, namely an INF file, one or more SYS files and a Catalog file (contains the signatures for the INF and .sys files). [The CD / website zip file may optionally have an additional README and possibly a setup.bat to run DPInst.exe.]

USBLAN from Windows Update Installs Seamlessly
For 99% of Windows 7 users who go with the Microsoft default OS setup and have an active internet connection (and a legal, activated copy of Windows!) Plug-N-Play will automatically find and install the Belcarra USBLAN driver. The user will see a small 'New Hardware Found' applet icon in the toolbar. This can be clicked on and will tell that Windows Update is being searched, etc.. No other user interaction should be required