http://www.rfc-editor.org/rfc/rfc8122.txt
RFC 8122: Connection-Oriented Media Transport over the Transport Layer Security (TLS) Protocol in the Session Description Protocol (SDP), J. Lennox, C. Holmberg2017-03-01T23:00:00-00:00This document obsoletes RFC 4572 by clarifying the usage of multiple fingerprints.