[jitsi-dev] jitmeet DTLS and key sizes


I know that webRTC, and therefore jitmeet, uses DTLS for security (I think
SDES is no longer in the race).
My question is regarding the key sizes employed (I'm assuming the cipher
used is AES).
I was under the impression that jitmeet was using self-signed certificates
to negotiate a symmetric 128 bit AES key for each stream.
But recently I decided to sniff my browser's traffic during a jitmeet
session and I could have sworn I saw certificates on the wire mentioning
256 bit keys. Was I dreaming there or does jitmeet actually use 256 bit AES
keys, or does the current standard still mandate 128?