RFC3611, "RTP Control Protocol Extended Reports (RTCP XR)" established
  a framework to allow new information to be conveyed in RTCP, 
  supplementing the original report blocks defined in RFC 3550, "RTP: A 
  Transport Protocol for Real-Time Applications".
  
  The XRBLOCK working group is chartered to work within this framework, 
  evaluating proposals for report block definitions containing new 
  metrics. The group will follow the guidelines established in RFC5968, 
  "Guidelines for Extending the RTP Control Protocol (RTCP)" and RTP 
  Monitoring Architecture being developed in the AVTCORE working group.
  The group will consider the guidelines for performance metric 
  development currently being discussed in the PMOL working group.
  



Milestones

Done     - Submit RTCP XR Report Block for Measurement Identity Reporting to IESG

Done     - Submit RTCP XR Report Block for Delay metric Reporting to IESG

Done     - Submit RTCP XR Report Block for Packet Delay Variation Metric Reporting to IESG

Done     - Submit RTCP XR Report Block for Discard metric Reporting to IESG

Done     - Submit RTCP XR Report Block for Run Length Encodings of Discarded Packets to
           IESG

Done     - Submit RTCP XR Report Block for Burst/Gap Discard metric Reporting to IESG

Done     - Submit RTCP XR Report Block for Burst/Gap Loss metric Reporting to IESG

Done     - Submit RTCP XR Report Block for QoE Metrics Reporting to IESG

Done     - Submit RTCP XR Report Block for Jitter Buffer Metric Reporting to IESG

Done     - Submit RTCP XR Report Block for Summary Statistics Metrics Reporting

Done     - Submit RTCP XR Report Block for Transport Stream (TS) Decodability Metric

Done     - Submit RTCP XR Report Block for Loss Concealment metric Reporting to IESG

Done     - Submit RTCP XR Report Block for Synchronization Delay and Offset Metrics
           Reporting

Done     - Submit RTCP XR Report Block for Bytes Discarded Metrics Reporting to IESG

Done     - Submit RTCP XR Report Block for MPEG2 Transport Stream (TS) Program Specific
           Information (PSI) Decodability Statistics Metrics Reporting to IESG