BT This document describes an RTCP XR report block, which reports packet transport parameters. The report block was developed by BT for pre-standards use in BT's next-generation network. This document has been produced to describe the report block in sufficient detail to register the block type with IANA in accordance with the Specification Required policy of RFC 3611. This specification does not standardise the new report block for use outside BT's network. This memo provides information for the Internet community.