If you have no dial tone, try the following steps:

  1. For analogue handsets, ensure the phone is directly connected to the phone port of the ATA (Analogue Telephone Adapter), or VoIP Modem. E.g. Cisco SPA122, Mitron MV1, TP-Link TD-VG3631
  2. For desktop IP handsets, ensure the phone is connected to your network, either to a modem/router or a switch and is powered on.
  3. Ensure the internet connection your phone is connected to is working.
  4. Reboot your network in a sequential sequence. Power down all devices, then turn on each device in order starting from the Modem/Router then onto the Phones/ATA.