You can use two ATA
's to create an ethernet phone extension:
Phone --> ATA
--> Ethernet LAN --> ATA
You will need to select ATA
s that can be configured to support this kind of application. Something like the Linksys
PAP2T or equivalent should work.
Free VOIP devices are almost always tied to a contract for VOIP services and cannot be used with other services.
Whether your VOIP phone number is listed in the White pages depends on which VOIP provider you use. The only reliable way to find out if a provider can do white page listings is to contact them.