This chapter defines how Telemetry Network Standard (TmNS)-specific data (TmNSDataMessages) are transferred between applications. A DataSource shall transmit TmNSDataMessages and a DataSink shall receive TmNSDataMessages. A DataChannel identifies a logical network connection used to transfer TmNSDataMessages between a DataSource and DataSink. This document describes how DataChannels are allocated and managed via application data transfer resources. Chapter 25 defines the associated management resources. Chapter 21 Appendix 21-B describes the bit numbering, bit ordering, and byte ordering conventions used in this chapter. A DataChannel may be established by submitting a ResourceRequest to specific application data transfer resources or via metadata (i.e., described in a Metadata Description Language [MDL] instance document).