No longer supported: Outdated TLS versions for encryption with estos online services
State of knowledge
May 2025
estos online services (UCConnect) Outdated: Transport encryption TLS 1.0/1.1
From 17 September 2025, older insecure TLS versions will no longer be supported by our online services (UCConnect).
Transport encryption for the connection to UCConnect
Which TLS versions are supported?
Transport encryption via
TLS 1.2
optional TLS 1.3
Which TLS versions are no longer supported/deactivated?
Transport encryption via
TLS 1.0
TLS 1.1
Recommendation: Use Microsoft operating systems with the latest security patches
The deactivation mainly affects older operating systems that have not received the latest security updates , as well as systems with manually customised security settings.
Systems that fulfil our system requirements are generally not affected by this deactivation. Further information can be found at: ProCall Enterprise system requirements
Microsoft also offers a comparison matrix for operating systems and TLS 1.2 client support, which can be viewed here: Microsoft TLS/SSL Protocol Matrix
These resources show that standard Windows installations are not usually affected.
Microsoft discontinues TLS 1.0 and 1.1
You can find information and details on the discontinuation of these protocols in the official Microsoft publications:
The discontinuation of the outdated and insecure TLS versions 1.0 and 1.1 for transport encryption to UCConnect services will take place on .
Affected components on older Microsoft operating systems without security updates are the UCServer with UCConnect connection and the ProCall Client for Windows (in VPN-less mode).
The currently supported browser versions used for the ProCall App for Web are not affected. Further information can be found at: caniuse. com - TLS 1.2
The currently supported operating systems for the ProCall mobile apps are also not affected.
