Blueface - NTL Modem

A question about using the Blueface service with NTL broadband - I see you can purchase an Analog Telephone Adaptor (Linksys Pap2) or a combined Router/ATA and have read that if your cable modem has only one ethernet port you need the router/ata combination for Blueface to work.

If however the NTL modem has one ethernet port and also one USB port (and either can be used for the broadband) is it possible that the ATA on its own would work plugged into the ethernet port while the pc used broadband through the usb port - or can both ports be used simultaneously?

Hope the question is put in a way that you know what I'm asking!

Podge, this [broken link removed] link has a note in it to suggest that both will not work at the same time but Id check with NTLs tech support who are normally quite informative.