What is an easy method to test whether UDP traffic is blocked?

What is an easy method for an Android device to tell whether a data connection (either WiFi or mobile data alone) has UDP traffic blocked? Many corporate and public access points restrict UDP access, and I am looking for a way to detect this manually. I am interested in this because real-time VOIP applications, for example, should not be expected to work with the same performance on TCP as on UDP. For the purposes of this question, I would assume that the data connection is either: 1. using hole-punching or 2. blocks all UDP traffic that is not DNS-related. Also, please assume the Android device is not rooted.