Hello, I have an application that relies on the NBXTSP TAPI driver (v. 6.0.10). The driver is running against an NBX V3000 Analog (v 6.0.63). All this runs on Windows 2003 R2 23-bit (Service Pack 2).

My app runs perfectly fine for months at a time. However, every now and then, TAPI will become confused (I can't really find a better word) and as a result my app will crash. I dug into the NBXTSP logs (located at C:\Program Files\3Com\NBX\NBX TSP\logs) and found the following errors:

0706:011213 NBXTSP E T049C **** GetPhoneExtension(): Extension is not found under key (null)!
0706:011213 NBXTSP L T0924 TSPI_lineGetExtensionID() invoked (returning 0)
0706:011213 NBXTSP L T049C TSPI_lineGetDevCaps() invoked ### device 7
0706:011213 NBXTSP E T049C **** GetPhoneExtension(): Extension is not found under key (null)!
0706:011213 NBXTSP L T0924 TSPI_lineGetExtensionID() invoked (returning 0)
0706:011213 NBXTSP L T049C TSPI_lineGetDevCaps() invoked ### device 8

Once the log starts showing the Extension is not found under key (null) errors, the system cannot be used until the box is rebooted.

Can someone please shed some light as to what this error means, what I can do to avoid it and how can I detect it from my app (if it cannot be avoided)?

I've seen no other errors in the Event Log or elsewhere. I've looked at the Win2003 TAPI Management Console and everything is fine there too.

Best regards