YANG Model Conversion
draft-yby-yang-model-conversion-00

Abstract

This document introduces the grammer extensions and relavant rules for YANG 1.0 to complete the mapping between two similar YANG modules that describe the same entity.

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Table of Contents

• 1. Introduction
• 2. Requirements Language
• 3. Overview
• 4. Terminology
• 5. Mapping Relationships
• 5.1. One-to-one Mapping
• 5.2. One-to-many Mapping
• 5.3. One-to-none Mapping
• 6. Grammer Extension for YANG
• 6.1. The mapto Statement
• 6.2. The statements Statement
• 6.2.1. The statements's Substatements
• 6.2.2. The source Substatement
• 6.2.3. The destination Substatement
• 6.2.4. Usage example
• 6.3. The maptype Statement
• 6.3.1. The value of oto
• 6.3.2. The value of otm
• 6.3.3. The value of otn
• 6.3.4. Usage example
• 6.4. The deviation Statement
• 6.4.1. Usage example
• 7. Mapping for statements
• 7.1. Mapping of module Statement
• 7.2. Mapping of submodule Statement
• 7.3. Mapping of typedef Statement
• 7.4. Mapping of type Statement
• 7.5. Mapping of container Statement
• 7.6. Mapping of leaf Statement
• 7.7. Mapping of leaf-list Statement
• 7.8. Mapping of list Statement
• 7.9. Mapping of choice Statement
• 7.10. Mapping of anyxml Statement
• 7.11. Mapping of grouping Statement
• 7.12. Mapping of uses Statement
• 7.13. Mapping of rpc Statement
• 7.14. Mapping of notification Statement
• 7.15. Mapping of augment Statement
• 7.16. Mapping of identity Statement
• 7.17. Mapping of extension Statement
• 7.18. Mapping of conformance-related Statements
• 7.19. Mapping of common Statements
• 8. Synchronization among Multiple Model's Datastores
• 9. Mapping Deviation Evaluation
• 10. Acknowledgements
• 11. IANA Considerations
• 12. Security Considerations
• 13. References
• 13.1. Normative References
• 13.2. Informative References
• Appendix A. Additional Stuff
• Authors' Addresses

1. Introduction

YANG 1.0 and YANG 1.1 are proposed originally as a domain-specific language to define the network model for NETCONF protocol. Based on YANG language, some organizations define their own public network models, and many companies (the equipment manufacturer, the telecom operators, the Internet companies, etc.) define their private models. Therefore, a network entity (device, etc.) MAY be described as different YANG data trees by different organizations and companies. In some cases, the data is required to be converted among different YANG models. This document proposes some extensions, named Yang Model Conversion (YMC), for YANG 1.0 to define the mapping rules of the nodes under the schema tree. By using YMC, the conversion rules MUST be clear, and the information deviation of conversion SHOULD be evaluated properly.

2. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

3. Overview

YMC is consisted of a set of new statements based on YANG language. These statements are designed to represent the mapping relationships of one-to-one, one-to-many, and one-to-none for different schema nodes under different XPath. The statements that includes leaf, leaf-list, list, etc. MAY be mapped to other statements with some limitations. For the nested usage of statements, the mapping statements SHOULD be also nested. When there is a big gap between two YANG models, the mapping deviation MAY be introduced and result in failures in networks. YMC proposes a method to evaluate the information loss while mapping. Thus, the performance SHOULD be predicted, and some potential risks SHOULD be avoided in advance.

4. Terminology

The following terminologies are defined in this document:

• YMC - YANG model conversion.
• map set - a set of map nodes that define the mapping rules between two YANG modules. A YANG file SHOULD include only one map set.
• map node - a node in the map set that SHOULD be used to map the schema node from one module to the schema node in another module.
• mapto - a node of map nodes.
• statements - a node of map nodes.
• maptype - a node of map nodes.
• oto - a value of maptype node that means the one-to-one mapping.
• otm - a value of maptype node that means the one-to-many mapping.
• otn - a value of maptype node that means the one-to-none mapping.

5. Mapping Relationships

5.1. One-to-one Mapping

5.2. One-to-many Mapping

5.3. One-to-none Mapping

6. Grammer Extension for YANG

6.1. The mapto Statement

6.2. The statements Statement

6.2.1. The statements's Substatements

6.2.2. The source Substatement

6.2.3. The destination Substatement

6.2.4. Usage example

6.3. The maptype Statement

6.3.1. The value of oto

6.3.2. The value of otm

6.3.3. The value of otn

6.3.4. Usage example

6.4. The deviation Statement

6.4.1. Usage example

7. Mapping for statements

This section divides all statements of YANG 1.0 into several kinds of categories.

7.1. Mapping of module Statement

7.2. Mapping of submodule Statement

7.3. Mapping of typedef Statement

7.4. Mapping of type Statement

7.5. Mapping of container Statement

7.6. Mapping of leaf Statement

7.7. Mapping of leaf-list Statement

7.8. Mapping of list Statement

7.9. Mapping of choice Statement

7.10. Mapping of anyxml Statement

7.11. Mapping of grouping Statement

7.12. Mapping of uses Statement

7.13. Mapping of rpc Statement

7.14. Mapping of notification Statement

7.15. Mapping of augment Statement

7.16. Mapping of identity Statement

7.17. Mapping of extension Statement

7.18. Mapping of conformance-related Statements

7.19. Mapping of common Statements

8. Synchronization among Multiple Model's Datastores

9. Mapping Deviation Evaluation

10. Acknowledgements

This document is Supported by BUPT Excellent Ph.D. Students Foundation (CX2019314).

11. IANA Considerations

This memo includes no request to IANA.

12. Security Considerations

All drafts are required to have a security considerations section. See RFC 3552 for a guide.

13. References

13.1. Normative References

13.2. Informative References

Appendix A. Additional Stuff

This becomes an Appendix.

Authors' Addresses