Visit our website http://www.pki.tu-dortmund.de using the safari browser of your device .Click T-Telesec GlobalRoot Class 2 and download the certificate.
After downloading the certificate you will get the notification "Profil geladen".
Close this notification.
Open the Settings of your iOS.
Navigate to General -> Profile and open the certificate "T-TeleSec GlobalRoot Class 2".
Click "Install"
Click "Finish".
Now you can connect to the network of Technische Universität Dortmund.