virtual COM/Modem port over USB

NTDEV
1

Hi,

We have a functional USB driver that is tested and working properly.
We need to emulate both a virtual COM port and Modem port over this.

I would like to know how to achieve this functionality? Do I have to write a
WDM upper filter driver that provides the serial interface? Or do I have to
update the existing driver to create a COM port symbolic link and handles
the Serial IOCTLs?

Thanks in advance.

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2

> WDM upper filter driver that provides the serial interface? Or do I have to

update the existing driver to create a COM port symbolic link and handles
the Serial IOCTLs?

The second is true.

If this is a virtual modem - you must also handle the AT commands properly,
respond to SERENUM properly by returning some ID, and have a modem INF file
where this ID is listed together with the AT commands you will respond to.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com