Is my USRobotics internal fax modem voice compatible?

[royaljelly]

I'm trying to run a telephone answering software on my PC using my US Robotics fax modem. But somehow it's not recognizing it as a proper mode, yet I'm able to fax out and receive files using a program called Winblast.

How can I find out if it's voice compatible, so that my software can run?

Here's the specs (I have no clue which protocol is for voice):

http://www.usr.com/products/home/home-product.asp?type=specs&sku=USR5670

Standards and Protocols Supported

* V.92 56K ITU standard
* V.90 56K ITU standard
* V.34 33.6K ITU standard
* Compatible with most ITU and Bell standards down to 300 bps
* V.80 video conferencing support
* V.42,MNP2-4 error control
* V.44,V.42 bis, MNP5 data compression
* Fax:EIA 578 (Class 1) with V.17, V.29, V.27 ter

If I need to buy another modem, which standards/protocol should I look for to ensure it supports voice calls?

Thanks.