Internet-Draft | Yang for Optical Path Computation | March 2022 |
Busi, et al. | Expires 8 September 2022 | [Page] |
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).¶
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[I-D.ietf-teas-yang-path-computation] describes key 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 optical technologies, including Optical Transport Network (OTN), Wavelength Switched Optical Networks (WSON), Flexi-grid, and multi-layer Optical network.¶
This document defines 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 require 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].¶
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].¶
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].¶
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 Table 1.¶
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.¶
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 Traffic Engineering (TE) attributes, such as requested path and tunnel attributes, defined in [I-D.ietf-teas-yang-path-computation], are still applicable when requesting 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].¶
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¶
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].¶
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].¶
Figure 2 below shows the tree diagram of the YANG data model defined in module ietf-wson-path-computation.yang.¶
Figure 3 below shows the tree diagram of the YANG data model defined in module ietf-flexi-grid-path-computation.yang.¶
Figure 4 below shows the tree diagram of the YANG data model defined in module ietf-otn-path-computation.yang.¶
<Add any security considerations>¶
This document registers the following URIs in the "ns" subregistry within the "IETF XML registry" [RFC3688].¶
URI: urn:ietf:params:xml:ns:yang:ietf-otn-path-computation Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-wson-path-computation Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-flexi-grid-path-computation Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace.¶
This document registers the following YANG module in the "YANG Module Names" registry [RFC7950].¶
name: ietf-otn-path-computation namespace: urn:ietf:params:xml:ns:yang:ietf-otn-path-computation prefix: otn-pc reference: this document name: ietf-wson-path-computation namespace: urn:ietf:params:xml:ns:yang:ietf-wson-path-computation prefix: wson-pc reference: this document name: ietf-flexi-grid-path-computation namespace: ietf:params:xml:ns:yang:ietf-flexi-grid-path-computation prefix: flexg-pc reference: this document¶
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.¶
The authors of this document would also like to thank Young Lee, Haomian Zheng, Victor Lopex, Ricard Vilalta, Bin Yeong Yoon, Jorge E. Lopez de Vergara Mendez, Daniel Perdices Burrero, Oscar Gonzalez de Dios, Gabriele Galimberti, Zafar Ali, Daniel Michaud Vallinoto and Dhruv Dhody who have contributed to the development of path computation augmentations for WSON and Flexi-grid topology in earlier versions of [I-D.ietf-ccamp-wson-tunnel-model] and of [I-D.ietf-ccamp-flexigrid-tunnel-yang].¶
This document was prepared using kramdown.¶