GOnnect is an open-source softphone client for business telephony, aimed at companies and public bodies. The client focuses on maintainability, integration into the Linux desktop, provisioning and simple operation. According to the developer it supports headsets and queues, among other features, and connects through open interfaces to existing infrastructure, from directory services to video and chat systems. The source code is public and the software can be downloaded via GitHub and Flathub. The licence is GPL-2.0-or-later.
GOnnect is an initiative of GONICUS GmbH of Arnsberg, Germany. No foreign owner was found. It is a client that you install yourself; there is no separate hosted service. Call and user data therefore sit on the telephony platforms and servers you choose, and according to the pages available the client itself does not send data to a vendor cloud. Because the code is public, you can have it reviewed and depend less on a single vendor. An explicit GDPR statement for the client does not appear on the pages reviewed; ask the vendor if you take support.