An analog telephone adapter (ATA) is required to convert the fax signals from standard telephone signals to VoIP. For more information on Cisco ATA devices and installation, see Get Started with Your Cisco ATA 191 and 192, Improve Fax Transmission with Your ATA, and Configure an ATA Device for a User.
Also note, this system works over your NETWORK (not your phone wires). It will connect to up to 4 standard phone lines (or Internet-based VoIP service) but the connection between the phones and the UCM6204 "base" are done over a Ethernet NETWORK. The bad news is that if you only have phone lines running everywhere (2 or 4 wires only) then you will have to run new wiring. The good news is that if you already have a computer network and computers at each phone location, these phones can be connected to that existing network. (If you only have one network jack per location, the phones' built-in network switch lets you "pass" the network connection through the phone to your computer so both can be connected).

The first impression callers experience. Make sure the phone prompts that welcome and guide the callers are clear, concise, and professional, with a voice that matches your brand and culture. You may not get a second chance.
02Hello, you’ve reached [your name] of [your company/business]. I’m sorry that I’m not available to answer your call now. Please leave your details and a brief message at the tone and I’ll make sure your message reaches the right person. This is the perfect voicemail for a department’s secretary or operatory to let those calling know that their message will be delivered when you get back.