Internet-Draft | Yang for Optical Path Computation | October 2021 |
Busi, et al. | Expires 25 April 2022 | [Page] |
- Workgroup:
- CCAMP Working Group
- Internet-Draft:
- draft-gbb-ccamp-optical-path-computation-yang-00
- Published:
- Intended Status:
- Standards Track
- Expires:
YANG Data Models for requesting Path Computation in Optical Networks
Abstract
This document describes YANG data models for Remote Procedure Calls (RPCs) to request Path Computation in Optical Networks (OTN, WSON and Flexi-grid).¶
The YANG data models defined in this document conforms to the Network Management Datastore Architecture (NMDA).¶
Status of This Memo
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.¶
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.¶
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This Internet-Draft will expire on 25 April 2022.¶
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the document authors. All rights reserved.¶
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.¶
1. Introduction
[I-D.ietf-teas-yang-path-computation] describes some use cases, where a client needs to request underlying SDN controllers for path computation. In some of these use cases the underlying SDN controller can control a single-layer (OTN, WSON or Flexi-grid) or multi-layer Optical network.¶
This document define YANG data models, which augment the generic Path Computation RPC defined in [I-D.ietf-teas-yang-path-computation], with technology-specific augmentations required to request path computation to an underlying Optical SDN controller. These models allow a client to delegate path computation tasks to the underlying Optical SDN controller without having to obtain optical-layer information from the controller and performing feasible path computation itself. This is especially helpful in cases where computing optically-feasible paths requires knowledge of physical-layer states, such as optical impairments, which are visible only to the Optical controller.¶
The YANG data model defined in this document conforms to the Network Management Datastore Architecture [RFC8342].¶
1.1. Terminology and Notations
Refer to [RFC7446] and [RFC7581] for the key terms used in this document. The following terms are defined in [RFC7950] and are not redefined here:¶
The following terms are defined in [RFC6241] and are not redefined here:¶
The terminology for describing YANG data models is found in [RFC7950].¶
1.2. Tree Diagram
A simplified graphical representation of the data model is used in Section 3 of this document. The meaning of the symbols in these diagrams is defined in [RFC8340].¶
1.3. Prefix in Data Node Names
In this document, names of data nodes and other data model objects are prefixed using the standard prefix associated with the corresponding YANG imported modules, as shown in the following table.¶
Prefix | YANG module | Reference |
---|---|---|
l0-types | ietf-layer0-types | [RFC9093] |
l0-types-ext | ietf-layer0-types-ext | [RFCYYYY] |
l0-types | ietf-layer0-types | [RFC8776] |
l1-types | ietf-layer1-types | [RFCZZZZ] |
te | ietf-te | [RFCKKKK] |
tep | ietf-te-path-computation | [RFCJJJJ] |
flexg-pc | ietf-flexi-grid-path-computation | RFCXXXX |
wson-pc | ietf-wson-path-computation | RFCXXXX |
otn-pc | ietf-otn-path-computation | RFCXXXX |
RFC Editor Note: Please replace XXXX with the RFC number assigned to this document. Please replace YYYY with the RFC number assigned to [I-D.ietf-ccamp-layer0-types-ext]. Please replace ZZZZ with the RFC number assigned to [I-D.ietf-ccamp-layer1-types]. Please replace KKKK with the RFC number assigned to [I-D.ietf-teas-yang-te]. Please replace JJJJ with the RFC number assigned to [I-D.ietf-teas-yang-path-computation]. Please remove this note.¶
2. YANG Data Models for Optical Path Computation
2.1. YANG Models Overview
The YANG data models for requesting WSON, Flexi-grid and OTN path computation are defined as augmentations of the generic Path Computation RPC defined in [I-D.ietf-teas-yang-path-computation], as shown in Figure 1.¶
The entities and TE attributes, such as requested path and tunnel attributes, defined in [I-D.ietf-teas-yang-path-computation], are still applicable when requestiong WSON, Flexi-grid and OTN path computation and the models defined in this document only specifies the additional technology-specific attributes/information, using the attributes defined in [RFC9093], [I-D.ietf-ccamp-layer0-types-ext] and [I-D.ietf-ccamp-layer1-types].¶
The YANG modules ietf-wson-path-computation, ietf-flexi-grid-path-computation and ietf-otn-path-computation defined in this document conforms to the Network Management Datastore Architecture (NMDA) defined in [RFC8342].¶
2.2. Attributes Augmentation
The common characteristics for layer 0 (WSON and Flexi-grid) tunnels are under definition in [I-D.ietf-ccamp-layer0-types-ext] and re-used in the ietf-wson-path-computation and ietf-flexi-grid-path-computation YANG models¶
2.3. Bandwidth Augmentation
As described in Section 4.2 of [RFC7699], there is some overlap between bandwidth and label in layer0.¶
The WSON and flexi-grid label resource information described in Section 2.4, is sufficient to describe also the spectrum resources within WSON and flexi-grid networks. Therefore, the model does not define any augmentation for the te-bandwidth containers defined in [I-D.ietf-teas-yang-path-computation].¶
The OTN path computation model augments all the occurrences of the te-bandwidth container with the OTN technology specific attributes using the otn-link-bandwidth and otn-path-bandwidth groupings defined in [I-D.ietf-ccamp-layer1-types].¶
2.4. Label Augmentations
The models augment all the occurrences of the label-restriction list with WSON, Flexi-grid and OTN technology specific attributes using the l0-label-range-info and flexi-grid-label-range-info groupings defined in [RFC9093] and the otn-label-range-info grouping defined in [I-D.ietf-ccamp-layer1-types].¶
Moreover, the models augment all the occurrences of the te-label container with the WSON, Flexi-grid and OTN technology specific attributes using the wson-label-start-end, wson-label-hop, wson-label-step, flexi-grid-label-start-end, flexi-grid-label-hop and flexi-grid-label-step defined in [RFC9093] and the otn-label-start-end, otn-label-hop and otn-label-step groupings defined in [I-D.ietf-ccamp-layer1-types].¶
3. Optical Path Computation Tree Diagrams
3.1. WSON Path Computation Tree Diagrams
Figure 2 below shows the tree diagram of the YANG data model defined in module ietf-wson-path-computation.yang.¶
3.2. Flexi-grid Path Computation Tree Diagrams
Figure 3 below shows the tree diagram of the YANG data model defined in module ietf-flexi-grid-path-computation.yang.¶
3.3. OTN Path Computation Tree Diagrams
Figure 4 below shows the tree diagram of the YANG data model defined in module ietf-otn-path-computation.yang.¶
6. Security Considerations
<Add any security considerations>¶
7. IANA Considerations
<Add any IANA considerations>¶
8. References
8.1. Normative References
- [I-D.ietf-ccamp-layer0-types-ext]
- Beller, D., Belotti, S., Zheng, H., Busi, I., and E. L. Rouzic, "A YANG Data Model for Layer 0 Types - Revision 2", Work in Progress, Internet-Draft, draft-ietf-ccamp-layer0-types-ext-00, , <https://www.ietf.org/archive/id/draft-ietf-ccamp-layer0-types-ext-00.txt>.
- [I-D.ietf-ccamp-layer1-types]
- Zheng, H. and I. Busi, "A YANG Data Model for Layer 1 Types", Work in Progress, Internet-Draft, draft-ietf-ccamp-layer1-types-11, , <https://www.ietf.org/archive/id/draft-ietf-ccamp-layer1-types-11.txt>.
- [I-D.ietf-teas-yang-path-computation]
- Busi, I., Belotti, S., Lopez, V., Sharma, A., and Y. Shi, "YANG Data Model for requesting Path Computation", Work in Progress, Internet-Draft, draft-ietf-teas-yang-path-computation-16, , <https://www.ietf.org/archive/id/draft-ietf-teas-yang-path-computation-16.txt>.
- [I-D.ietf-teas-yang-te]
- Saad, T., Gandhi, R., Liu, X., Beeram, V. P., Bryskin, I., and O. G. D. Dios, "A YANG Data Model for Traffic Engineering Tunnels, Label Switched Paths and Interfaces", Work in Progress, Internet-Draft, draft-ietf-teas-yang-te-27, , <https://www.ietf.org/archive/id/draft-ietf-teas-yang-te-27.txt>.
- [RFC6241]
- Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, , <https://www.rfc-editor.org/info/rfc6241>.
- [RFC7699]
- Farrel, A., King, D., Li, Y., and F. Zhang, "Generalized Labels for the Flexi-Grid in Lambda Switch Capable (LSC) Label Switching Routers", RFC 7699, DOI 10.17487/RFC7699, , <https://www.rfc-editor.org/info/rfc7699>.
- [RFC7950]
- Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, , <https://www.rfc-editor.org/info/rfc7950>.
- [RFC8340]
- Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, , <https://www.rfc-editor.org/info/rfc8340>.
- [RFC8342]
- Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, , <https://www.rfc-editor.org/info/rfc8342>.
- [RFC8776]
- Saad, T., Gandhi, R., Liu, X., Beeram, V., and I. Bryskin, "Common YANG Data Types for Traffic Engineering", RFC 8776, DOI 10.17487/RFC8776, , <https://www.rfc-editor.org/info/rfc8776>.
- [RFC9093]
- Zheng, H., Lee, Y., Guo, A., Lopez, V., and D. King, "A YANG Data Model for Layer 0 Types", RFC 9093, DOI 10.17487/RFC9093, , <https://www.rfc-editor.org/info/rfc9093>.
8.2. Informative References
- [I-D.ietf-teas-actn-poi-applicability]
- Peruzzini, F., Bouquier, J., Busi, I., King, D., and D. Ceccarelli, "Applicability of Abstraction and Control of Traffic Engineered Networks (ACTN) to Packet Optical Integration (POI)", Work in Progress, Internet-Draft, draft-ietf-teas-actn-poi-applicability-03, , <https://www.ietf.org/archive/id/draft-ietf-teas-actn-poi-applicability-03.txt>.
- [RFC7446]
- Lee, Y., Ed., Bernstein, G., Ed., Li, D., and W. Imajuku, "Routing and Wavelength Assignment Information Model for Wavelength Switched Optical Networks", RFC 7446, DOI 10.17487/RFC7446, , <https://www.rfc-editor.org/info/rfc7446>.
- [RFC7581]
- Bernstein, G., Ed., Lee, Y., Ed., Li, D., Imajuku, W., and J. Han, "Routing and Wavelength Assignment Information Encoding for Wavelength Switched Optical Networks", RFC 7581, DOI 10.17487/RFC7581, , <https://www.rfc-editor.org/info/rfc7581>.
Acknowledgments
The authors of this document would like to thank the authors of [I-D.ietf-teas-actn-poi-applicability] for having identified the gap and requirements to trigger this work.¶
This document was prepared using kramdown.¶