CCAMP Working Group H. Zheng Internet-Draft Huawei Technologies Intended status: Standards Track Y. Lee Expires: November 14, 2020 Samsung A. Guo Futurewei V. Lopez Telefonica D. King University of Lancaster May 13, 2020 A YANG Data Model for Layer 0 Types draft-ietf-ccamp-layer0-types-05 Abstract This document defines a collection of common data types and groupings in the YANG data modeling language. These derived common types and groupings are intended to be imported by modules that model Layer 0 optical Traffic Engineering (TE) configuration and state capabilities such as Wavelength Switched Optical Networks (WSONs) and Flexi-grid Dense Wavelength Division Multiplexing (DWDM) Networks. 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/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on November 14, 2020. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. Zheng, et al. Expires November 14, 2020 [Page 1] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology and Notations . . . . . . . . . . . . . . . . 3 1.2. Prefix in Data Node Names . . . . . . . . . . . . . . . . 3 2. Layer 0 Types Module Contents . . . . . . . . . . . . . . . . 3 3. YANG Code for Layer 0 Types . . . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . 16 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 17 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 8.1. Normative References . . . . . . . . . . . . . . . . . . 18 8.2. Informative References . . . . . . . . . . . . . . . . . 18 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20 1. Introduction YANG [RFC7950] is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols such as NETCONF [RFC6241]. The YANG language supports a small set of built-in data types and provides mechanisms to derive other types from the built-in types. This document introduces a collection of common data types derived from the built-in YANG data types. The derived types and groupings are designed to be the common types applicable for modeling Traffic Engineering (TE) features as well as non-TE features (e.g., physical network configuration aspect) for Layer 0 optical networks in model(s) defined outside of this document. The applicability of Layer 0 types specified in this document include Wavelength Switched Optical Networks (WSONs) [RFC6163] and [ITU-Tg6982], and Flexi-grid Dense Wavelength Division Multiplexing (DWDM) Networks [RFC7698] and [ITU-Tg6941] . Zheng, et al. Expires November 14, 2020 [Page 2] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 1.1. Terminology and Notations Refer to [RFC7446] and [RFC7581] for the key terms used in this document, and the terminology for describing YANG data models can be found in [RFC7950]. The YANG data model in this document conforms to the Network Management Datastore Architecture defined in [RFC8342]. 1.2. 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. +-------------+---------------------------+----------------------+ | Prefix | YANG module | Reference | +-------------+---------------------------+----------------------+ | l0-types | ietf-layer0-types | [RFCXXXX] | +-------------+---------------------------+----------------------+ Note: The RFC Editor will replace XXXX with the number assigned to the RFC once this document becomes an RFC. YANG module ietf-layer0-types (defined in Section 3) references [RFC6163], [RFC7205], and [RFC7698]. 2. Layer 0 Types Module Contents This document defines YANG module for common Layer 0 types, ietf- layer0-types. This module is used for WSON and Flexi-grid DWDM networks. The ietf-layer0-types module contains the following YANG reusable types and groupings: l0-grid-type: A base YANG identity for the grid type as defined in [RFC6163] and [RFC7698]. dwdm-ch-spc-type: A base YANG identity for the DWDM channel spacing type as defined in [RFC6205]. cwdm-ch-spc-type: Zheng, et al. Expires November 14, 2020 [Page 3] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 A base YANG identity for the CWDM channel spacing type as defined in [RFC6205]. wson-label-start-end: A YANG grouping that defines the label-start and label-end for WSON as defined in [RFC6205]. wson-label-hop: A YANG grouping that defines the label hop for WSON as defined in [RFC6205]. l0-label-range-info: A YANG grouping that defines the layer 0 label range information applicable for both WSON per priority level as defined in [RFC6205]. This grouping is used in the flexi-grid DWDM by adding more flexi- grid-specific parameters. wson-label-step: A YANG grouping that defines label steps for WSON as defined in [I-D.ietf-teas-yang-te-types]. flexi-grid-label-start-end: A YANG grouping that defines the label-start and label-end for flexi- grid as defined in [RFC7698]. flexi-grid-label-hop: A YANG grouping that defines the label hop for both single channel and multiple carriers in flexi-grid DWDM, as defined in [RFC7698]. flexi-grid-label-range-info: A YANG grouping that defines flexi-grid label range information and per priority level as defined in [RFC7698] and [RFC8363]. flexi-grid-label-step: A YANG grouping that defines flexi-grid label steps as defined in [I-D.ietf-teas-yang-te-types]. Zheng, et al. Expires November 14, 2020 [Page 4] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 3. YANG Code for Layer 0 Types file "ietf-layer0-types@2020-05-13.yang" module ietf-layer0-types { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-layer0-types"; prefix "l0-types"; organization "IETF CCAMP Working Group"; contact "WG Web: WG List: Editor: Haomian Zheng Editor: Young Lee Editor: Aihua Guo Editor: Victor Lopez Editor: Daniel King "; description "This module defines Optical Layer 0 types. This module provides groupings that can be applicable to Layer 0 Fixed Optical Networks (e.g., CWDM (Coarse Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing)) and Flexi-grid Optical Networks. Copyright (c) 2020 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see Zheng, et al. Expires November 14, 2020 [Page 5] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 the RFC itself for full legal notices."; revision "2020-05-13" { description "Initial Version"; reference "RFC XXXX: A YANG Data Model for Layer 0 Types"; } typedef dwdm-n { type int16; description "The given value 'N' is used to determine the nominal central frequency. The nominal central frequency, 'f' is defined by: f = 193100.000 GHz + N x channel-spacing (measured in GHz) where 193100.000 GHz (193.100000 THz) is the ITU-T 'anchor frequency' for transmission over the C band; and where 'channel-spacing' is defined by the dwdm-ch-spc-type."; reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers, ITU-T G.694.1 (02/2012): Spectral grids for WDM applications: DWDM frequency grid"; } typedef cwdm-n { type int16; description "The given value 'N' is used to determine the nominal central wavelength. The nominal central wavelength is defined by: Wavelength = 1471 nm + N x channel-spacing (measured in nm) where 1471 nm is the ITU-T 'anchor wavelength' for transmission over the C band; and where 'channel-spacing' is defined by the cwdm-ch-spc-type."; reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers, ITU-T G.694.2 (12/2003): Spectral grids for WDM applications: CWDM wavelength grid"; } typedef flexi-n { type int16; description Zheng, et al. Expires November 14, 2020 [Page 6] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 "The given value 'N' is used to determine the nominal central frequency. The nominal central frequency, 'f' is defined by, f = 193100.000 GHz + N x channel-spacing (measured in GHz), where 193100.000 GHz (193.100000 THz) is the ITU-T 'anchor frequency' for transmission over the C band; and where 'channel-spacing' is defined by the flexi-ch-spc-type. Note that the term 'channel-spacing' can be alternated by the term 'nominal central frequency granularity' defined in clause 7 of ITU-T G.694.1."; reference "RFC7698: Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks. ITU-T G.694.1 (02/2012): Spectral grids for WDM applications: DWDM frequency grid"; } typedef flexi-m { type uint16; description "The given value 'M' is used to determine the slot width. A slot width is defined by: slot width = M x SWG (measured in GHz), where SWG is defined by the flexi-slot-width-granularity."; reference "RFC7698: Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks. ITU-T G.694.1 (02/2012): Spectral grids for WDM applications: DWDM frequency grid"; } identity l0-grid-type { description "Layer 0 grid type"; reference "RFC6163:Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs), ITU-T G.694.1 (02/2012): Spectral grids for WDM applications: DWDM frequency grid, ITU-T G.694.2 (12/2003): Spectral grids for WDM applications: CWDM wavelength grid"; } Zheng, et al. Expires November 14, 2020 [Page 7] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 identity flexi-grid-dwdm { base l0-grid-type; description "Flexi-grid"; reference "RFC7698: Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks, ITU-T G.694.1 (02/2012): Spectral grids for WDM applications: DWDM frequency grid"; } identity wson-grid-dwdm { base l0-grid-type; description "DWDM grid"; reference "RFC6163:Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs), ITU-T G.694.1 (02/2012): Spectral grids for WDM applications: DWDM frequency grid"; } identity wson-grid-cwdm { base l0-grid-type; description "CWDM grid"; reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers, ITU-T G.694.2 (12/2003): Spectral grids for WDM applications: CWDM wavelength grid"; } identity dwdm-ch-spc-type { description "DWDM channel spacing type"; reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers, ITU-T G.694.1 (02/2012): Spectral grids for WDM applications: DWDM frequency grid"; } identity dwdm-100ghz { base dwdm-ch-spc-type; description "100GHz channel spacing"; Zheng, et al. Expires November 14, 2020 [Page 8] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 } identity dwdm-50ghz { base dwdm-ch-spc-type; description "50GHz channel spacing"; } identity dwdm-25ghz { base dwdm-ch-spc-type; description "25GHz channel spacing"; } identity dwdm-12p5ghz { base dwdm-ch-spc-type; description "12.5GHz channel spacing"; } identity flexi-ch-spc-type { description "Flexi-grid channel spacing type"; reference "RFC7698: Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks ITU-T G.694.1 (02/2012): Spectral grids for WDM applications: DWDM frequency grid"; } identity flexi-ch-spc-6p25ghz { base flexi-ch-spc-type; description "6.25GHz channel spacing"; } identity flexi-slot-width-granularity { description "Flexi-grid slot width granularity"; } identity flexi-swg-12p5ghz { base flexi-slot-width-granularity; description "12.5GHz slot width granularity"; } Zheng, et al. Expires November 14, 2020 [Page 9] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 identity cwdm-ch-spc-type { description "CWDM channel spacing type"; reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers, ITU-T G.694.2 (12/2003): Spectral grids for WDM applications: CWDM wavelength grid"; } identity cwdm-20nm { base cwdm-ch-spc-type; description "20nm channel spacing"; } /* Groupings. */ grouping wson-label-start-end { description "The WSON label-start or label-end used to specify WSON label range."; choice grid-type { description "Label for DWDM or CWDM grid"; case dwdm { leaf dwdm-n { type l0-types:dwdm-n; description "The central frequency of DWDM. "; reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers"; } } case cwdm { leaf cwdm-n { type l0-types:cwdm-n; description "Channel wavelength computing input. "; reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers"; } } } reference "RFC6205: Generalized Labels for Zheng, et al. Expires November 14, 2020 [Page 10] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 Lambda-Switch-Capable (LSC) Label Switching Routers"; } grouping wson-label-hop { description "Generic label hop information for WSON"; choice grid-type { description "Label for DWDM or CWDM grid"; case dwdm { choice single-or-super-channel { description "single or super channel"; case single { leaf dwdm-n { type l0-types:dwdm-n; description "The given value 'N' is used to determine the nominal central frequency."; } } case super { leaf-list subcarrier-dwdm-n { type l0-types:dwdm-n; description "The given values 'N' are used to determine the nominal central frequency for each subcarrier channels."; reference "ITU-T Recommendation G.694.1: Spectral grids for WDM applications: DWDM frequency grid"; } } } } case cwdm { leaf cwdm-n { type l0-types:cwdm-n; description "The given value 'N' is used to determine the nominal central wavelength."; reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers"; } } } reference "RFC6205: Generalized Labels for Zheng, et al. Expires November 14, 2020 [Page 11] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 Lambda-Switch-Capable (LSC) Label Switching Routers"; } grouping l0-label-range-info { description "Information for layer 0 label range."; leaf grid-type { type identityref { base l0-grid-type; } description "Grid type"; } leaf priority { type uint8; description "Priority in Interface Switching Capability Descriptor (ISCD)."; reference "RFC4203."; } reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers"; } grouping wson-label-step { description "Label step information for WSON"; choice l0-grid-type { description "Grid type: DWDM, CWDM, etc."; case dwdm { leaf wson-dwdm-channel-spacing { type identityref { base dwdm-ch-spc-type; } description "Label-step is the channel-spacing (GHz), e.g., 100.000, 50.000, 25.000, or 12.500 GHz for DWDM"; reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers"; } } case cwdm { leaf wson-cwdm-channel-spacing { type identityref { base cwdm-ch-spc-type; } description Zheng, et al. Expires November 14, 2020 [Page 12] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 "Label-step is the channel-spacing (nm), i.e., 20 nm for CWDM, which is the only value defined for CWDM"; reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers"; } } } reference "RFC6205: Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers ITU-T G.694.2 (12/2003): Spectral grids for WDM applications: CWDM wavelength grid"; } grouping flexi-grid-label-start-end { description "Label-start and Label-end information for Flexi-grid."; leaf flexi-n { type l0-types:flexi-n; description "The given value 'N' is used to determine the nominal central frequency."; } reference "RFC7698: Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks"; } grouping flexi-grid-frequency-slot { description "Flexi-grid frequency slot grouping."; uses flexi-grid-label-start-end; leaf flexi-m { type l0-types:flexi-m; description "The given value 'M' is used to determine the slot width."; } reference "RFC7698: Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks"; } grouping flexi-grid-label-hop { description "Flexi-grid path label."; choice single-or-super-channel { Zheng, et al. Expires November 14, 2020 [Page 13] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 description "single or super channel"; case single { uses flexi-grid-frequency-slot; } case super { list subcarrier-flexi-n { key flexi-n; uses flexi-grid-frequency-slot; description "List of subcarrier channels for flexi-grid super channel."; } } } reference "RFC7698: Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks"; } grouping flexi-grid-label-range-info { description "Info of Flexi-grid-specific label range"; uses l0-label-range-info; container flexi-grid { description "flexi-grid definition"; leaf slot-width-granularity { type identityref { base flexi-slot-width-granularity; } default flexi-swg-12p5ghz; description "Minimum space between slot widths. Default is 12.500 GHz"; reference "RFC7698: Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks"; } leaf min-slot-width-factor { type uint16 { range "1..max"; } default 1; description "Slot width range: two multipliers of the slot width , granularity, each indicating the minimal and maximal slot width supported by a port, respectively. Zheng, et al. Expires November 14, 2020 [Page 14] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 Minimum slot width is calculated by: Minimum slot width (GHz) = min-slot-width-factor * slot-width-granularity"; reference "RFC8363: GMPLS OSPF-TE Extensions in Support of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks"; } leaf max-slot-width-factor { type uint16 { range "1..max"; } description "Slot width range: two multipliers of the slot width , granularity, each indicating the minimal and maximal slot width supported by a port, respectively. Maximum slot width is calculated by: Maximum slot width (GHz) = max-slot-width-factor * slot-width-granularity"; reference "RFC8363: GMPLS OSPF-TE Extensions in Support of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks"; } } } grouping flexi-grid-label-step { description "Label step information for flexi-grid"; leaf flexi-grid-channel-spacing { type identityref { base flexi-ch-spc-type; } default flexi-ch-spc-6p25ghz; description "Label-step is the nominal central frequency granularity (GHz), e.g., 6.25 GHz"; reference "RFC7699: Generalized Labels for the Flexi-Grid in Lambda Switch Capable (LSC) Label Switching Routers"; } leaf flexi-n-step { type uint8; description "This attribute defines the multiplier for the supported values of 'N'. For example, given a grid with a nominal central frequency Zheng, et al. Expires November 14, 2020 [Page 15] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 granularity of 6.25 GHz, the granularity of the supported values of the nominal central frequency could be 12.5 GHz. In this case, the values of flexi-n should be even and this constraints is reported by setting the flexi-n-step to 2. This attribute is also known as central frequency granularity in RFC8363."; reference "RFC8363: GMPLS OSPF-TE Extensions in Support of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks"; } } } 4. Security Considerations The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446]. The NETCONF access control model [RFC8341] provides the means to restrict access for particular NETCONF users to a preconfigured subset of all available NETCONF protocol operations and content. The NETCONF Protocol over Secure Shell (SSH) [RFC6242] describes a method for invoking and running NETCONF within a Secure Shell (SSH) session as an SSH subsystem. The NETCONF access control model [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. The YANG module in this document defines optical layer 0 type definitions (i.e., typedef, identity and grouping statements) in YANG data modeling language to be imported and used by other layer 0 specific modules. When imported and used, the resultant schema will have data nodes that can be writable, or readable. The access to such data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations. Zheng, et al. Expires November 14, 2020 [Page 16] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 The security considerations spelled out in the YANG 1.1 specification [RFC7950] apply for this document as well. 5. IANA Considerations It is proposed that IANA should assign new URIs from the "IETF XML Registry" [RFC3688] as follows: URI: urn:ietf:params:xml:ns:yang:ietf-layer0-types Registrant Contact: The IESG XML: N/A; the requested URI is an XML namespace. This document registers following YANG modules in the YANG Module Names registry [RFC7950]. name: ietf-layer0-types namespace: urn:ietf:params:xml:ns:yang:ietf-layer0-types prefix: l0-types reference: RFC XXXX(TBD) 6. Acknowledgements The authors and the working group give their sincere thanks for Robert Wilton for the YANG doctor review, and Tom Petch for his comments during the model and document development. 7. Contributors Dhruv Dhody Huawei Email: dhruv.ietf@gmail.com Bin Yeong Yoon ETRI Email: byyun@etri.re.kr Ricard Vilalta CTTC Email: ricard.vilalta@cttc.es Italo Busi Huawei Email: Italo.Busi@huawei.com Zheng, et al. Expires November 14, 2020 [Page 17] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 8. References 8.1. Normative References [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . 8.2. Informative References [I-D.ietf-teas-yang-te-types] Saad, T., Gandhi, R., Liu, X., Beeram, V., and I. Bryskin, "Traffic Engineering Common YANG Types", draft-ietf-teas- yang-te-types-13 (work in progress), November 2019. [ITU-Tg6941] International Telecommunication Union, "Spectral grids for WDM applications: DWDM frequency grid", ITU-T G.694.1, February 2012. Zheng, et al. Expires November 14, 2020 [Page 18] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 [ITU-Tg6982] International Telecommunication Union, "Amplified multichannel dense wavelength division multiplexing applications with single channel optical interfaces", ITU-T G.698.2, November 2018. [ITU-Tg709] International Telecommunication Union, "Interfaces for the optical transport network", ITU-T G.709, June 2016. [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6163] Lee, Y., Ed., Bernstein, G., Ed., and W. Imajuku, "Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)", RFC 6163, DOI 10.17487/RFC6163, April 2011, . [RFC6205] Otani, T., Ed. and D. Li, Ed., "Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers", RFC 6205, DOI 10.17487/RFC6205, March 2011, . [RFC7205] Romanow, A., Botzko, S., Duckworth, M., and R. Even, Ed., "Use Cases for Telepresence Multistreams", RFC 7205, DOI 10.17487/RFC7205, April 2014, . [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, February 2015, . [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, June 2015, . [RFC7698] Gonzalez de Dios, O., Ed., Casellas, R., Ed., Zhang, F., Fu, X., Ceccarelli, D., and I. Hussain, "Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks", RFC 7698, DOI 10.17487/RFC7698, November 2015, . Zheng, et al. Expires November 14, 2020 [Page 19] Internet-Draft A YANG Data Model for Layer 0 Types May 2020 [RFC8363] Zhang, X., Zheng, H., Casellas, R., Gonzalez de Dios, O., and D. Ceccarelli, "GMPLS OSPF-TE Extensions in Support of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks", RFC 8363, DOI 10.17487/RFC8363, May 2018, . Authors' Addresses Haomian Zheng Huawei Technologies H1, Huawei Xiliu Beipo Village, Songshan Lake Dongguan, Guangdong 523808 China Email: zhenghaomian@huawei.com Young Lee Samsung South Korea Email: younglee.tx@gmail.com Aihua Guo Futurewei Email: aihuaguo@futurewei.com Victor Lopez Telefonica Email: victor.lopezalvarez@telefonica.com Daniel King University of Lancaster Email: d.king@lancaster.ac.uk Zheng, et al. Expires November 14, 2020 [Page 20]