DESC: Now you can eliminate the need for extra dedicated telephone lines with the ComSwitch 3500. It lets up to 3 devices - usually a telephone, answering machine, fax or modem - share a single phone line.??As soon as you or your answering machine picks up an inbound call, the CS 3500 starts listening for a fax calling tone. If you answer the call and hear a fax calling tone, all you have to do is hang up and the CS 3500 will send the call to the fax machine. If you're not at home when a call comes in, as soon as your answering machine starts playing its outgoing message, the same thing happens - fax calls go to the fax machine and voice callers leave a message. So long as you have an answering machine to plug in, this is about as simple as it gets. If an answering machine is not required for voice calls, all calls will be transferred to your fax or modem after 6 rings. It also enables you to require security codes for inbound calls which is great for dealing with unwanted junk fax trans...