-- Point-to-Point -- Quite a number of enterprises have dedicated pairs of fax machines, such as between the sales department and the warehouse. You can use simple FXS interfaces on your routers, riding on existing data links between the locations. Just use Private Line Automatic Ringdown if the fax machines support simple off-hook, or program the appropriate number into the router.

-- Reducing the number of Phone Lines -- You can make your VOIP network fax-aware, such that the voice gateways detect analog fax tone and take appropriate action. This enables you to reduce the cost of analog phone lines, since the same line can detect if the incoming call voice or fax. Unfortunately, this often runs into multivendor interoperability problems.

-- Headquarters and Branches -- Using store-and-forward, a headquarters can send a single e-mail to multiple destinations.