None of our phones are working; we get dead air. No calls coming (going right to voice mail) and not able to phone out. The odd thing is, we have high speed internet and that is working fine (connected to the phone line). How is this possible and do you have any suggestions? Very frustrated in Wisconsin

Call your house from another number and see if it rings and rings, or rings busy.
If it rings busy, their may be a short, voltage normally around 48 volts dc, on hook.
When you lift receiver(or go off hook), may drop to less than 10 volts.
Try removing all devices plugged in to phone jacks.
Do you have an alarm system?

You probably have phone off hook somewhere. You'll just have to track it down. Going directly to voice mail suggests the line is busy. A "dead" phone line suggests the line is busy.
Good internet suggests the line is OK.