I am writing from Berlin, Germany, so things may be different here.
My ISP gives the AVM FritzBox as cable modem to its customers. (www.avm.de
- and they offer an English website also).
This box is a real wonder concerning its possibilities. They also offer a tool for download, that enables the box to send and receive fax. It works with MS Office and almost any Windows.
It is not really easy to use, there is quite some try and error involved to get used to it, but then ... it works.
Maybe you just want to check out the tool itself. I do not think it is "chained" to the FritzBox cable modem.