Is your IP phone not working? Check these quick fixes

VoIP Phones, also known as IP Phones, are normally very easy to use and don’t require much maintenance once they’re installed. There are however issues, most often related to outside factors or network configuration, that can cause abnormal behavior of your IP Phone.

From experience, we have gathered some of the most common issues VoIP users face when using their IP Phones, and some quick fixes and verification. Most of these will be asked by the technician troubleshooting your issue if you call your VoIP provider, so it’s easier to take a look first and have the information ready for them instead of having to check while on the phone with support.

Most common causes of “Registration error”, “Not Registered” or “SIP Registration failed” error messages on an IP Phone

The ‘Registration error” and “Not Registered” and other similar error messages are some of the most common errors a VoIP user can notice on the screen of his IP Phone. Here are some of the most predictable issues behind these errors:

  1. The existence of an Internet connection is one of the first things to verify; check your connection by browsing the Internet using a computer connected to the same network.
  2. Initial provisioning (registration) requires more bandwidth than regular use. Slow connections may cause failure in phone registration; ensure that you give your IP Phone enough time before it’s ready to be used.
  3. Internet connections have firewalls that may block receiving calls; ask your network administrator or Internet Service Provider to disable firewall or set port triggering.
  4. If you are using hardware that you configured, re-enter your configuration credentials in the phone’s configuration settings. If it has been pre-configured by your VoIP provider, contact them to ensure that your credentials have been set up correctly into the phone’s configuration.

My phone shows a “Link is down” message

  1. Link is down means there is no direct communication between your phone and the Internet.
  2. Verify your Internet connection by browsing the Internet using a computer connected to the same network.
  3. Check for loose cables.
  4. Check cables for damages.

What to do if the screen of your IP Phone is blank

Based by the state of your VoIP phone line, if you find that the screen of your IP Phone is blank, please make these quick verifications before calling your VoIP provider:

If your phone line is not working:

  1. Verify if your IP phone’s power adapter smells like burnt.
  2. Ensure that your IP phone is properly plugged.
  3. Connect your IP phone to another power outlet.

If your phone line is working:

  1. Verify if your screen has been broken.
  2. Verify if the protective sheet on your screen was removed.
  3. Verify your screen’s brightness settings.

Phone keeps rebooting

An IP Phone that reboots itself continuously might be a sign of issues with your VoIP device, Hosted PBX extension conflict, or simple updates. Here’s a list of basic verifications that you can do to find the root of this behavior:

  1. Verify if the power adaptor used is the correct one sent with the package.
  2. Cycle time for different IP phones may take up to 4 reboot cycles to finalize initial registration, ensure that you wait for the cycle to be complete.
  3. Depending on the IP phone make and model, automatic firmware updates may cause the phone to reboot; this process may take from a few minutes to an hour and happens at least once every 6 months. If the rebooting persists continue troubleshooting.
  4. Verify your IP phone buttons and keypad for any stuck keys; this may cause phone to initiate a system restart. Press all the buttons and verify if the keys pop up properly.
  5. Another cause could be the constant change of the IP address, which indicates a router issue. An IP address is a numerical label given by your network and one is specific to each device connected. When an IP address changes, most IP phone models trigger a reboot cycle. Verify with your network administrator if you may be using a load balancer (a device that switches connections between two Internet Service Providers). This could cause the IP Phone to try to shift between two different IP addresses from time to time.
  6. Is your phone configured for several VoIP providers? For multiline phones attempting to register different VoIP providers/ accounts may cause instability and initiate reboot. Some IP phones may not be able to handle different SIP server targets.

How to reboot an IP Phone

Your phone might require a reboot after significant changes that might affect your VoIP service. From changes in your ISP’s network settings to power outages or Internet outages that affect your service, there are various factors that can be eliminated with a simple reboot, bringing your phone line back to full functionality.

For a correct reboot of your IP Phone it is important to completely power down all equipment, wait the appropriate amount of time, and then power up your equipment in the proper successive order as described below:

  1. Unplug only the power cable from the back of your Cable/DSL modem.
  2. If you have a network router, unplug its power cable.
  3. Unplug the power cable from the back of the IP Phone.
  4. Wait at least 2 minutes or follow the Cable/DSL modems manufacturer’s instructions before powering up any equipment.
  5. If you have a router, plug the power cable back in and wait for it to start up completely before continuing.
  6. Plug your Cable/DSL modem’s power cable back into your phone and wait for it to start up completely before continuing.
  7. Plug in the power cable for the IP Phone.
  8. Your phone display should now show the line as active. Pick up the telephone receiver and listen for a dial tone. You should now be able to make and receive calls using your Hosted PBX