Is the stream really DTLS encrypted?

[Babis Chatzinakis]

Hello,

I recently started playing with Janus and specifically with the streaming plugin. So I have gstreamer streaming a video flow to Janus via RTP (no SRTP so no encryption

here). Then I connect to Janus with Chrome and I can watch the video. So far so good. I then decided to monitor the traffic with wireshark to get a grasp of what's happening under the hood. I can see the DTLS handshake completed normally as well as the subsequent video UDP packets. I was hoping to see something DTLS-related to every UDP packet so that I know that the packets are encrypted but that's not the case. What's even more surprising is that when I watch the video through Firefox, Wireshark reports the packets as RTP (and not UDP). So that got me worrying a little bit. Doesn't the fact that I am seeing RTP packets mean that there is no encryption? Otherwise, how can Wireshark dissect the RTP header? Am I missing something?

BR,

Babis

[Lorenzo Miniero]

DTLS is used just for the handshake: media uses SRTP, which encrypts the content but not the header (and that's why Wireshark detects it).

L.