http://www.rfc-editor.org/rfc/rfc6323.txt
RFC 6323: Sender RTT Estimate Option for the Datagram Congestion Control Protocol (DCCP), G. Renker, G. Fairhurst2011-07-01T23:00:00-00:00It is integrated into the feature set of DCCP as an end-to-end negotiable extension. [STANDARDS-TRACK]