Prevent Nuisance calls - Yealink T19, T20, T26 & T28 IP Phones

A number of our Deskphone customers have reported getting frequent nuisance calls from 1000, 1001 or similar three & four digit numbers. On answering the calls the line appears to be dead with no one at the other end. This seems to be more prevalent among users that are using BT home broadband to connect to DeskPhone.

What is causing this issue?

These nuisance calls are due to automated port scanning tools, used by hackers looking for PBX systems to break into. Firstly, please do not be alarmed by this, your phones and systems are secure and the hackers are unable to gain access to your phone or our systems, however we understand that the calls are a nuisance. 

How can I get this to stop? 

In order to get this to stop you will have to follow the following steps; (as always, if you require assistance with this please contact us and we will be happy to guide you through it).

1. Log onto your phone

Firstly we are going to have to get the IP address of your phone. The easiest way to get this information is by pressing the button in the centre of the directional keys on your phone. This will be either an 'OK' button or a Tick depending on the model of Yealink phone you have (See Below). Then pressing the sequence 2, 1, 1, 2 on your keypad. 

This will bring up your phones WAN IP

Your IP address is listed as the WAN IP (192.168.XX.XXX)

Open a browser and type this IP address into the address bar

This will bring up a username and password dialogue box. Enter the default Yealink username and password in here (see below).

2. Disable IP Calls

The IP Call feature allows the phone to make and receive calls through it's IP address. You will need to disable this feature.

WEB UI path:

Features->General Information-> Allow IP Call

Set this option to 'Disabled' as shown below.

Note: If you're running old firmware or a product that is EOL 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.

3. Enable SIP trust:

The SIP trust feature allows the phone to only accept messages from a trusted server specified in your account settings page. You will need to enable this feature.

WEB UI path:

Features->General Information-> Accept SIP Trust Server Only

Set this option to 'Enabled' as shown below.

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@desk-phone.com or call us on 02034342068.