I've spent a few hours digging through captures and RFCs and I think I found where I'm getting caught - having the server key isn't enough - you need the client key (i.e. from your browser). I've got a couple of issues I'm tracking down with WebRTC support for FreeSwitch, does anybody know how to export private keys from Chrome/Firefox that they use for WebRTC? If I can get the browser private key AND the key from Freeswitch (dtls-srtp.key by the looks) then I can decrypt a DTLS stream and figure out what's going on.

Cheers

Sam