ZEDAT (Zentraleinrichtung für Datenverarbeitung) is the computer service center at Freie Universität Berlin. It provides data processing, internet, and email facilities to all members of the university. After you have enrolled as a student or doctoral student at Freie Universität, ZEDAT will send you all the necessary information to open your FU email account, which allows you to access the services of ZEDAT including Internet, etc.
As an employee of the university, you need access to various IT systems, including email, WLAN, registration of your office computer, and placement of orders at the online shop (BIOS). Therefore you will need to request an email account, your Freie Universität account, which is assigned by the university's computer service center (ZEDAT) by filling in, having the form signed by your research institute, and submitting the following form (in German). You can download the form here. Contact information for service staff can be found on the form.