Skip to main content

🛡️ Prevent Nuisance/ghost calls - Yealink Phones

ONSIM
Updated

Have you been receiving calls from 3 or 4-digit numbers like 1000 or 1001, only to find silence when you answer? These are known as "Ghost Calls."

What is causing this?

These are not real phone calls. They are caused by automated "port scanning" tools used by bots to look for vulnerable systems.

  • Are you secure? Yes. These bots cannot access your phone or the ONSIM network; they are simply "knocking on the door."

  • Why me? This is particularly common for users on BT Home Broadband, though it can happen on any network.

How to Stop Ghost Calls

Follow these three steps to block these automated pings.

Step 1: Access your Phone’s Web Interface

  1. Find your IP Address: Press the OK button (or the tick button) in the center of the directional keys on your Yealink phone.

  2. Note the WAN IP: You will see a number like 192.168.1.XXX.

  3. Log In: Type that IP address into the address bar of your web browser on a computer connected to the same network.

  4. Enter Credentials:

    • Username: admin

    • Password: admin

    If these credentials do not work, please contact us at support@onsim.uk so we can provide your specific login or assist remotely.

Step 2: Disable "Allow IP Call"

This feature allows calls to be made directly to your IP address, bypassing our secure servers.

  • Path: Go to the Features tab → General Information.

  • Action: Locate Allow IP Call and set it to Disabled.

Step 3: Enable "SIP Trust"

This ensures your phone only "listens" to ONSIM’s trusted servers.

  • Path: Go to the Features tab → General Information.

  • Action: Locate Accept SIP Trust Server Only and set it to Enabled.

Important: Scroll to the bottom and click Confirm to save your changes.

⚠️ Technical Notes

  • Firmware Version: If you have an older or "End of Life" Yealink model (firmware version below 80), these specific menu options may not appear. 

  • Caution: Please do not change other settings in the Web UI, particularly in the "Account" or "Network" tabs, as this may cause your phone to stop working.

Note: If you're running old firmware or a product that is EOL below version 80 then these options may not be available in the Web UI for your phone. These changes will need to made in the phones firmware configuration files directly.

Once both these options are set scroll to the bottom of the page and click confirm. This will save your changes and you can now exit the WEB UI by logging out and closing that browser window. 

 

Note: Please be very careful not to change any of the other settings in the dashboard. Changing certain settings may cause the phone to stop working especially within the account settings pane.

As always if you require any additional help please contact us at support@onsim.uk

Related articles