Is a Yealink T4xS or CP9x0 phone suitable for the SwyxON feature RemoteConnector for Yealink?

The information in this article applies to the following products:

• Yealink Desktop Phone T41S
• Yealink Desktop Phone T42S
• Yealink Desktop Phone T46S
• Yealink Desktop Phone T48S
• Yealink Conference Phone CP920
• Yealink Conference Phone CP960
• SwyxON Version 13.30 or higher
• AddOn "Swyx RemoteConnector for Yealink"

SUMMARY

With SwyxON version 13.30, the connection of a Yealink phone is also supported without a dedicated corporate VPN connection to the Enreach Data Center (e.g. from the home office or a small branch office).
However, older devices of the T4S and CP9x0 series, built before January 1, 2019, do not meet the mandatory technical requirements.

This article describes how to determine the suitability of a phone in advance.

INFORMATION

With SwyxON Version 13.30 the new function "Swyx RemoteConnector for Yealink" is released. Similar to the "Swyx RemoteConnector for SwyxIt", it allows the operation of solitary Yealink phones outside the corporate network and the related corporate VPN connection to the Enreach Data Center.

In principle, the RemoteConnector for Yealink allows the connection of all Yealink phones supported by the Swyx platform (T5W series, T4S series, CP92x, CP96x). For security reasons, the phones are authenticated using mTLS based on the current state of the art and the recommendations of the BSI. However, older T4S-series and CP920/960 phones manufactured before January 1, 2019 do not meet this requirement.

The following describes how to determine in advance whether a device meets the requirements for operation on the Swyx RemoteConnector for Yealink.

Note: The activation of the AddOn "Swyx RemoteConnector for Yealink" and the connection of the phones is described in the Online Help in the SwyxON Partner Portal and the Swyx Control Center. 

CHECKING THE CONDITIONS FOR OPERATION

Unfortunately, it is not easy to identify whether a T4S/CP9x0 series device is suitable or not, e.g. from the serial number, the MAC address or even a printed production date.

Of course, you can also use "try and error" to determine whether a phone is suitable, but the following method is less time-consuming and more distinct:

• Use your web browser to connect to the web UI of the phone by entering the IP address of the phone: https://xxx.xxx.xxx.xxx. You can easily find the IP address in the phone's menu under "Menu/Status".
• The web browser will show you that the connection is not secure. You do not need to log in; instead, click on the "Not secure" message to the left of the URL input field: 

• The following steps now differ from browser to browser. In MS Edge, click on the ">" arrow next to the message about the insecure website (see image), in Google Chrome click on the "Certificate invalid" entry below the message:

• (Only Edge) Click on the Certificate Symbol on the upper right corner to review the used certificate:

• Open the Tab "Details" in the Certificate Viewer (Chrome/Edge), scroll down to the item "Certificate Signature Algorithm" und click:

• The corresponding value is now displayed in the field below, which shows whether the phone is suitable:
  • “PKCS #1 MD5 With RSA Encryption” → This phone is not supported by the Swyx RemoteConnector für Yealink
  • “PKCS #1 SHA-256 With RSA Encryption” → This phone is supported by the Swyx RemoteConnector for Yealink