This document specifies the Remote Desktop Protocol: Virtual Channel Echo Extension to Remote Desktop Protocol: Basic Connectivity and Graphics Remoting, as specified in [MS-RDPBCGR]. The echo messages defined in section 2.2 are used to bounce a payload sent by a terminal server off of a connected terminal-server client, thereby providing a simple mechanism to determine network characteristics such as round-trip time (RTT).
Sections 1.8, 2, and 3 of this specification are normative and can contain the terms MAY, SHOULD, MUST, MUST NOT, and SHOULD NOT as defined in RFC 2119. Sections 1.5 and 1.9 are also normative but cannot contain those terms. All other sections and examples in this specification are informative.