IP Phone troubleshooting


This document explores the different steps that an administrator of an Escaux UC system can take to troubleshooting phone related issues and to help identify and resolve the most common problems.

Gather information

To begin the troubleshooting procedure, It is important to know whether the problem is a network-related or a configuration problem. There are basic questions that need to be asked before an administrator can re-establish service on a phone:


  • Who has the problem, and who does not have the problem?
  • Identification of the problematic device: MAC address of the phone, extension, application identifier, customer reference (anything that can pinpoint the subject of the problem)
  • Is there a certain "group" of users having the same problem?


  • What is the impact?
  • What is the problem exactly? Which actions are taken when the problem occurs?
  • What are the symptoms exactly?
  • Is there some action that triggers the problem ("it only happens when...")
  • What did the customer already trying to resolve the problem? What were the results?


  • When did the problem occur? Was there a time when it did not occur? Has it always occurred?
  • Is there some frequency in the problem?


  • Where physically does the problem occur? Are there other places where the same problem does not occur?

General troubleshooting

If your IP phone suddenly stops working for no reason, there are some basic steps to follow in order to diagnose the problem and try to fix it by yourself or by your administrator.

Power issues

If your phone has no power, Verify that no lights appear on the phone when it is powered up.
  • Check if the phone is properly plugged into a PoE switch port that is operational.
  • Connect the phone in another place (switch port) where there is a working phone to check if the phone can boot.

Local connection issues

If the phone displays the message Netwotk Link is Down, the LAN cable might not be properly connected.
  • Check the switch is working and the lights are flashing and the LAN port is active.
  • Via the phone,
    DONE Navigate to: Menu> Satus> Network > Ethernet >LAN port : active
  • You can also connect to the SOP and ping the IP address of the phone to isolate the local connection problem.
  • You can try a reboot of the phone and check if the phone can register to the telephony server.

Boot Process troubleshooting

As an administrator, It is important to understand how the boot process of an IP phone works. If any IP phone fails to boot properly, It is likely a Network-related problem. In order to know what's wrong when an IP phone registers itself on the SOP, you should know the following basic steps when initializing:

  • The phone requests an IP address from a DHCP server.
  • The DHCP server gives the phone an IP address and additional information, such as the address of the TFTP server and/or IP PBX.
  • The phone connects to the TFTP server and receives configuration information and /or updated firmware.
  • The phone connects to the IP PBX and register itself with it.
  • The IP PBX configures the phone's operational features, namely the phone number, programmable buttons and more.

An IP phone is successfully registered with the IP PBX when the phone's display shows the extension number and the current date and time (without blinking). By this information, you are sure that the phone has received a valid IP address from the DHCP server, that the phone was able to communicate with the TFTP server and download the configuration file and the IP PBX was configured to recognize the phone.

Note that the phone could also show the wrong date and time because the SOP's NTP server is not properly filled, or the NTP server is not reachable.

If the IP phone fails any of these steps, the IP phone shows various status or error messages proving that something went wrong or didn't happen during the configuration. The most common message on Polycom for example, is something like "Configuration not found". This means the phone wasn't able to boot from the SOP with the new configuration and it has only booted with the last configuration set. However, this can vary by phone type and by firmware.

Registration issues

If your phone can't receive or make any call, it may be a registration related problem. You can check the phone status in the SMP interface (in Advanced menu) whether your phone is registered or not. This information can also be found on the SOP by executing the "sip show peers" command In Asterisk console.

If your IP phone is not registered, take the following actions to troubleshoot the problem:

  • Check if you have input the correct Mac address in the SMP:

DONE Navigate to: SMP > Resources > IP Phones

  • Check in phone settings menu of the phone if it has received an IP address from the DHCP server.

If the phone displays this error message could not contact Boot Server, it means that the phone can't receive tis configuration file because it is using an incorrect protocol (FTP or HTTP) to try to contact the server.
  • In the phone menu, check which protocol the phone is using and set the correct protocol which is TFTP Trivial FTP). You can find this information via:

DONE Navigate to: Menu > Settings > Advanced > Admin Settings > Network Configuration > Server Menu > Server Type= Trivial FTP

Incoming/Outgoing calls issues

  • Problem : only one phone is not able to place/receive a call
  • troubleshooting : Go to the SMP and go to the customer sopkey. Select the Fusion DC1 sopkey
DONE Navigate to: Advanced > Phone Status
check if the phone is "green", have an IP address.
  • Solution : restart the phone. If doesn' t work, forward to 2nd Level Helpdesk

  • Problem : all phones are not able to place/receive a call
  • Troubleshooting : nothing to do
  • Solution :
    • go to the SMP and go to the customer sopkey. Check if all "Fusion" sopkey are "green".
    • Forward to the 2nd level HelpDesk

  • Problem: A phone is registered and can make outgoing calls but incoming calls are not possible
  • Troubleshooting: Check the user's profile and the user's Intentional Status ( is it in Busy mode ?)
  • Solution: If none of these options were not activated, you can restart the device and test again to see if the phone receive incoming calls.

  • Problem: A user is not able to do the pickup call.
  • Troubleshooting: In the Internal Directory of the SMP, check if the extension of the user is in the same department of the extension you want to take the call from.
  • Solution: Configure the correct group of the extension that is having problem of group pickup

  • Problem: A phone is registered and can receive calls but outgoing calls are not possible
  • Troubleshooting: Make a test by calling an internal extension and an external number to identify which type of calls are not working (intern calls or external calls?)
  • Solution: If only external calls are are impacted, check if the number format dialed is correct (with leading 0)

  • Problem: A user is using PUM (Personal User Mobility) and you can't receive calls
  • Troubleshooting: check what is displayed on the phone. If it is the Id of the phone , you haven't logged in yet
  • Solution: Ask the user to do a PUM login and when the device has rebooted and displays the extension, test incoming calls to verify if it is reachable.

Dial tone issues

Sometimes the lack of a dial tone is caused by the lack of power on your phone. Check if the power cable is properly plugged. If you are using PoE, make sure that the switch is supplying power to the phone. Maybe the dial tone is not set on one of the audio modes. Switch between the Handset to the Speaker to see if the dial tone is present when the phone is on Speaker. If you hear the dial tone on one of the audio mode, you can fix the problem only on the Handset.

Ring tone issues

If your phone doesn't ring, the first think to verify is the Ring setting. Is your ringer turned on? Check if it is not turned off. Check if the volume is not low and adjust the level with the volume up/down keys. You can also check the status of the Headset, the Handset and the Speaker.

Audio quality / issues

If you have audio problem when calling
  • If one person has the problem
    • check if the headset is properly plugged into the jack marked Headset
    • you can test by connecting another handset (and/or RJ11 cable) to check if the issue is only located on the handset part.
    • Ensure the volume is correctly adjusted.
  • If more than one person,
    • Quality Problem between end-user when calling on the same site : check the network of this site
    • Quality Problem between end-user when calling from different site and no problem when calling on the same site : Check your intersite network
    • Quality problem only with external calls : Check with your telephony provider

Display issues

If there is no display or the display has bad contrast
  • Check if the LAN cable is properly plugged in. Try to unplug and re-insert the cable.
  • Check the contrast adjustment or reboot the phone to restore the default level of contrast

If the phone displays a warning triangle and you can clear this and learn more about this warning via the phone' Menu:

  • DONE Navigate to: Menu > Settings > Status > Diagnostic > Warning

How to reset a phone

In some cases, a phone can't update it's firmware or new configuration because the previous configuration is still present in caching. Doing a factory reset of the device can be necessary to solve the problem.

DONE Navigate to: Menu > Settings > Advanced > Admin Settings > Reset to Default >

Polycom provides several levels to reset a phone but we recommend you to select Reset Device Settings

  • Reset Local Configuration
  • Reset Web Configuration
  • Reset Device Settings
  • Format File System
  • Reset to Factory
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