MBIM: Exposing NIC before connecting RRS feed

  • Question

  • Hi,

    We are adapting our mobile broadband chipset to the Windows 8.1 MBIM driver. For development and debugging, we need the ability to communicate with the device before actually connecting with it to the network.

    As an analogy, when we don't use MBIM, we expose an RNDIS + Virtual COM composite interface. When the device is plugged in, this actually shows the device's NIC before actually sending AT commands to connect to the network. At this point we can communicate with the device to see what's going on in the device (through telnet for example).

    Can anyone advise on methods to enable such functionality?

    For example one option would be to send an MBIM command to tell the device to re-expose itself as an RNDIS device. (I suppose this would be done through a Windows app with MBIM API, correct?)

    Or perhaps we could send a command to only artificially connect to the network, and then we would have access to the NIC without actual connection.

    I'd appreciate to hear any other practical and creative ideas as to how to go about this. Obviously, the simpler the better.



    Tuesday, October 22, 2013 7:15 AM

All replies

  • The device is connected via USB only. There is no real serial port, however in our non-MBIM mode, we can expose a virtual COM port.

    Debug printing would not be enough. We need a possibility to communicate with the device like we could when it exposes RNDIS (NIC is visible even when not connected to mobile network), in which case we can open a telnet session to our device.


    Wednesday, October 23, 2013 6:09 AM
  • Thanks for your responses PA.

    We are trying to avoid working on a driver for the host side. We depend on the MBIM driver alone.

    Currently we have decided to write a small Windows 8 application which sends a proprietary command to tell the device to switch to RNDIS mode.

    If anyone has any other ideas, I'd appreciate to hear them anyway.


    • Proposed as answer by Pavel A Saturday, October 26, 2013 2:42 PM
    Thursday, October 24, 2013 1:48 PM