http://www.rfc-editor.org/rfc/rfc7002.txt
RFC 7002: RTP Control Protocol (RTCP) Extended Report (XR) Block for Discard Count Metric Reporting, A. Clark, G. Zorn, Q. Wu2013-09-01T23:00:00-00:00This document defines an RTP Control Protocol (RTCP) Extended Report (XR) block that allows the reporting of a simple discard count metric for use in a range of RTP applications.