ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / Today's telemetry systems need to be highly configurable and easily extensible to support a constantly growing number of data acquisition/transmitting components from different manufacturers. One way to achieve this goal is through a standardized descriptive language that can define the system structure as well as end-node devices. The integrated Network Enhanced Telemetry (iNET) program has explored such a possibility by creating a series of standards to define how devices are configured and interoperate with each other. As one of the standards created by the iNET program, the Metadata Description Language (MDL) specifies a common interchange language that defines and configures a Telemetry Network System (TmNS). MDL Instance Documents are used to exchange test requirements, data formats and configuration information among the devices within a TmNS system. MDL, together with other standards created in the iNET program, serve as a foundation for assembling a modern telemetry system. This paper starts with an overview of the MDL-based system description architecture. A typical configuration workflow of an MDL-based system is then described. iNET functionality implementations for new and legacy devices are used as examples to illustrate the power of MDL-based design, as well as the challenges and issues associated with the implementation of the MDL standard. We explain and evaluate the design decisions for a new product, the L-3 NetDAS Recorder, as the case study. We also discuss how a legacy Data Acquisition Unit (DAU) acting as an LTC Data Source Unit can be updated to support MDL based iNET functionality. Our practice shows that more efficient data acquisition systems can be designed and implemented using the metadata definition language as a core tool for equipment and system description. We conclude the paper with design tradeoffs and discussions.