How to Know If the Line Coming from the Telephone Company is Working.

1. Find the Network Interface Device (NID) mounted on a wall just outside your home. The NID is a small grey or tan plastic box where the cable coming from the utility pole runs into. 
2. Open the device and look inside the NID for the short telephone cable (about two inches long) plugged into a telephone jack. 
3. Unplug the short cable from its jack. 
4. Get a working telephone and plug the telephone into the jack.
5. Listen for a dial tone. No dial tone is indicative of a problem with the telephone company line. Call the telephone company and report the problem if there is no dial tone.

   Tips:

   Check the telephone you’re using to make sure it is working. You can plug the telephone to a neighbors jack to make sure it is working. 

Reference:

 Michigan.gov: Checking the phone at the Network Interface Device (NID)