Provisioning a Yealink T20, T22, T26, T28 for 3CX Phone System


The easiest way to set up a phone for use with 3CX PhoneSystem is to use the built-in provisioning functionality inside 3CX PhoneSystem. This will allow the phone to configure itself by retrieving a 3CX-generated phone configuration file. To fully take advantage of this, you can configure your DHCP Server to also deliver to the phone the location from where it can retrieve its configuration file – the result will be completely automated phone configuration.

This is a 3-step process:

  1. Enable provisioning for an extension to create the phone's configuration files
  2. Tell the phone where to get its configuration files from.
  3. Optionally configure advanced options such as Time Zone from the Phone Provisioning node.

Enabling Provisioning for an Extension

  1. Select the extension you want to provision and go to the "Phone Provisioning" tab.
  2. In the "MAC Address" field, enter the phone's 12-character MAC Address. This information is normally printed on the back of the phone.
  3. In the "Model" field, select the model number of the phone you want to provision
  4. Select the preferred display language for the phone. (Note Language packs need to be downloaded and placed in the firmware folder in 3CX.*)
  5. If your 3CX Phone System machine has multiple network interfaces, select the interface IP Address through which the phone will be connecting to the 3CX PhoneSystem machine using the "Select Interface" drop down. You can skip this step if you have only one network card in your 3CX Phone System machine.
  6. If you want to use the phone's Memory Keys and you have a T26 or a T28, you can set the BLF fields to monitor the status of other extensions and 3CX Shared park extensions.
  7. Click on the "OK" button at the bottom of the page to create the configuration files. These will be created in a folder on the web server, and picked up by the phone upon boot-up
  8. Now go to the phones node, select the phone and click 'Reprovision'. The phone will be rebooted and will apply the new configuration settings.

Getting the Phone to Retrieve its Configuration Files

Now the phones must be told to download the configuration files from the central server. There are two options for doing this:

  1. Provisioning using DHCP Option 66
    The preferred method is to set your IP phones to retrieve the provisioning URL automatically via DHCP Option 66. DHCP Servers can be set to not only deliver IP Addresses, DNS Servers, and Router IP Addresses to network devices, but can also specify a Boot Server Address, which most SIP Phones use to obtain the URL for retrieving configuration files.
    This is the recommended method for larger networks.

  2. Provisioning without using DHCP Option 66
    If you do NOT want to use DHCP Option 66, you will need to manually tell the phone where to retrieve its configuration files. To do this:
    1. Start up the phone and identify its IP Address – press the menu key on the phone, and select the "Settings" option. For this example we will assume the IP Address of the phone is, and IP Address of the 3CX PhoneSystem machine is
    2. Point your browser to the web interface of the phone:
    3. Click on the "Upgrade" tab, and then select the "Advanced" page.
    4. Set the "URL" field to: (IIS)
    5. Set the "Check New Config" field to "Power on"
    6. Click the "Confirm" button at the bottom of the page. Your phone will now save the new settings with the provisioning URL configured. You can trigger the phone to retrieve its provisioning file by clicking on the "Autoprovision" button.

Advanced configuration options (Time Zone, DST, Firmwares, Phone Display Language)

You can configure Time Zone, DST and other options from the Phone provisioning node. From here you can also edit the provisioning templates and include custom configuration options into the templates. Phone firmwares can also be upgraded network wide.

Plug and Play functionality

Yealink phones can be automatically detected by 3CX Phone System when they are connected to the network. In this case they will appear as ‘NEW’ in the phones node. You can then right-click on the phone to create a new extension or assign an existing extension to the phone. Fill in all the required information and select the appropriate template for your phone model from the Provisioning Tab. Click on Apply and OK to save changes. 3CX Phone System will send a SIP NOTIFY message to the phone with the provisioning URL inside. The Phone will accept this and provision automatically.
Some switches have the option to filter off multicast and or multicast storms. If that is enabled, it could prevent this function.