The NETCONF Working Group has completed a base protocol to be used for configuration management. However, the NETCONF protocol does not include a standard content layer. The specifications do not include a modeling language or accompanying rules that can be used to model the management information that is to be configured using NETCONF. This has resulted in inconsistent syntax and interoperability problems. The purpose of NETMOD is to support the ongoing development of IETF and vendor-defined data models for NETCONF. NETMOD's requirements are drawn from the RCDML requirements draft (draft-presuhn-rcdml) and documents referenced therein. The WG will define a "human-friendly" modeling language defining the semantics of operational data, configuration data, notifications, and operations. This language will focus on readability and ease of use. This language must be able to serve as the normative description of NETCONF data models. The WG will use YANG (draft-bjorklund-yang) as its starting point for this language. Language abstractions that facilitate model extensibility and reuse have been identified as a work area and will be considered as a work item or may be integrated into the YANG document based on WG consensus. The WG will define a canonical mapping of this language to NETCONF XML instance documents, the on-the-wire format of YANG-defined XML content. Only data models defined in YANG will have to adhere to this on-the-wire format. In order to leverage existing XML tools for validating NETCONF data in various contexts and also facilitate exchange of data models and schemas with other IETF working groups, the WG will define standard mapping rules from YANG to the DSDL data modeling framework (ISO/IEC 19757) with additional annotations to preserve semantics. The initial YANG mapping rules specifications are expressly defined for NETCONF modeling. However, there may be future areas of applicability beyond NETCONF, and the WG must provide suitable language extensibility mechanisms to allow for such future work. The NETMOD WG will only address modeling NETCONF devices and the language extensibility mechanisms. Any application of YANG to other protocols is future work. The WG will consult with the NETCONF WG to ensure that NETMOD's decision do not conflict with planned work in NETCONF (e.g., locking, notifications). While it is desirable to provide a migration path from existing MIB modules to YANG data models (modules), it is not a requirement to provide full compatibility between SMIv2 and YANG. The Working Group will determine which constructs (e.g., conformance statements) are not relevant for translation from SMIv2 to YANG. YANG is also permitted to introduce constructs that cannot be expressed in SMIv2. However, all basic types that can be represented in SMIv2 must be expressible in YANG. Initial deliverables are below. The working group may choose to combine multiple deliverables into a single document where deemed appropriate. 1. An architecture document explaining the relationship between YANG and its inputs and outputs. (informational) 2. The YANG data modeling language and semantics (proposed standard) 3. Mapping rules of YANG to XML instance data in NETCONF (proposed standard) 4. YIN, a semantically equivalent fully reversible mapping to an XML-based syntax for YANG. YIN is simply the data model in an XML syntax that can be manipulated using existing XML tools (e.g., XSLT) (proposed standard) 5. Mapping rules of YANG to DSDL data modeling framework (ISO/IEC 19757), including annotations for DSDL to preserve top-level semantics during translation (proposed standard). 6. A standard type library for use by YANG (proposed standard)