My plan is to have 2 numbers. One has typically been reserved for faxes. I will plug my fax machine into the Hub. I will have 2 other phones, each plugged in to it's own Scout. If I am on one phone and recieving a fax at the same time or both phones are being used at the same time and someone calls one of my 2 numbers will they go to voicemail or will they get a busy signal?
If they go to voicemail I'll be happy with that.
If they get a busy signal, is there a way to reduce that posibility, such as having a third phone number?
When you are using both lines you are basically using your "call waiting" line. So the third call will not show up as call waiting or anything. But it will go to voicemail.
If you are using both lines an incoming fax would be out of luck. You should sign up for the free k7.net fax service. Then faxes never get a busy signal and show up in your voicemail.