After Chrome and Microsoft dropped support for TLS 1.1, you want to know if it is possible to implement TLS 1.2 for Kerio Softphone?
You are getting the following error:
Asterisk: DTLS failure occurred on RTP instance '***' due to reason 'tlsv1 alert protocol version', terminating
Kerio Operator does not use TLS v1.2 as the default SSL/ TLS protocol. TLS v1.2 is only supported for the front-end server Nginx. As the product is EoE*, there are no changes planned regarding this issue.
*End of Engineering (EoE) of a software product means that GFI will no longer provide new releases, minor releases, defect logging, or defect fixes for affected products. Customers can continue to use EoE products unencumbered and add/subtract user licenses as necessary. In addition, Customer Support will continue to respond to issues and use reasonable efforts to assist customers, but no new, tested corrections will be generated. Known problems remain available, and the latest versions of software and fixes remain available for download.