A YANG Data Model for CMIS Access and Control

Digital Coherent Optics (DCO) modules enable routers or switches to directly connect to transport network, such as Optical Transport Network (e.g., DWDM or OTN) or Wavelength Division Multiplexing (WDM) network. DCO modules, such as CFP2-DCO and QSFP-DD DCO, implement optical connector (i.e., Tx and Rx) and Digital Signal Processor (DSP), and provide higher data rates (100 Gbps, 400 Gbps, and beyond) and flexible data transport. DCO transceivers, equipped by a platform device (e.g., a switch or a router), is generally controlled by network OS running on the device with Content Management Interoperability Specifications (CMIS) which is an open standard protocol designed to facilitate interoperability between management systems. The specification is defined in . CMIS also allows vendor-specific extensions of its transceiver features by using custom pages. For example, CMIS custom pages can be used for debugs of the transceiver. This document defines a YANG data model for accessing to and controlling CMIS for controlling DCO transceivers from outside of the platform device.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" this document are to be interpreted as described in BCP14, , when, and only when, they appear in all capitals, as shown here. The terms and their definitions used in this specification are described below: CMIS (Common Management Interface Specifications): A generic management communication interface together with a generic management interaction protocol between host and managed modules. The specification is defined in ; NACM (Network Configuration Access Control Model): A standard access control model to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. The specification is defined in . NETCONF (Network Configuration Protocol): Mechanisms to install, manipulate, and delete the configuration of network devices. The definitions and specification is described in ; RESTCONF: An HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in NETCONF. The specification is defined in . The following terms of NETCONF defined in are also used in this specification: (NETCONF) client configuration data datastore message remote procedure call (RPC) (NETCONF) server state data (NETCONF) user This document makes use of the terms defined in .

The following acronyms are used in this document: Customer Edge Command Data Block Digital Coherent Optics Digital Signal Processor Dense Wavelength Division Multiplexing Generalized Signal-to-Noise Ratio Inter-Integrated Circuit Network Operating System Network Management System Optical Transport Network Quality of Transmission Third Party Application Wavelength Division Multiplexing

The tree diagrams used in this document follow the notation defined in .

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 if ietf-interfaces cmis-ctrl ietf-cmis-control RFC XXXX Note: The RFC Editor will replace XXXX with the number assigned to the RFC once this draft becomes an RFC.

This section describes usecases of this YANG data model for accessing to and control CMIS and implementation patterns for using such YANG.

This YANG data model disaggregates management features for pluggable modules which a platform device equips with from NOS, and enables centralized control of such modules. For example, in case that a customer's router (i.e., CE) is connected to DWDM/OTN provided by a service provider, this enables pluggable optics modules installed to the customer's router to be controlled by a controller of the service provider as shown in . The service provider can configure DCO transceivers installed in customer devices directly depending on its own policy. Then, some access control with NACM defined in should be applied for preventing illegal configuration of the other than target modules or leak of information of the customer's devices.

On the other hand, in case that NOS of the platform device manages pluggable modules, CMIS control from remote controller might cause inconsistency problem of pluggable modules. More details of this problem is considered in .

By using this YANG data model, operators can obtain detailed DSP information contained in CMIS custom pages even if the modeling of the data is not standardized. Example uses of such detailed DSP information including fiber sensing (Ref. ), physical layer monitoring (Ref. ), and accurate estimation (e.g., GSNR) (Ref. ).

This document introduce two patterns to implement a client using an interface in which this YANG data model is available: Controller/NMS on Remote Host In this pattern, a controller or an NMS implements a client using this YANG data model, and control pluggable modules installed to a platform device. The overview is shown in . Application Running on the Platform Device In this pattern, a 3rd party's application running on a platform device implements a client using this YANG data model, and control pluggable modules installed to the device. That application can behave as a server using this YANG data model, or provide more generic interface, such as REST API to remote systems. The overview is shown in .

| APL | | | | `---' | | ,---V-----------. | | | NOS | | | `---------------' | | A | | | CMIS via | | V i2c bus | | +-------+ | +-------| DCO |-------+ +-------+ ]]>

The ietf-cmis-control is an augment to the ietf-interface. It allows the user to set the operating mode of CMIS for control pluggable devices as well as other operational parameters. cmis-control. The structure is shown below:

The "ietf-cmis-control" module contains the following YANG reusable YANG data types, identities and groupings:

cmis-control:: A base YANG identity for data nodes to access and control CMIS supported by the pluggable device equipped in the interface.
cmis-version:: A base YANG identity for the version of CMIS supported by the device.
cmis-pages:: A base YANG identity for the list of pages to be accessed or controlled.
cmis-page:: A base YANG identity for the page to be accessed or controlled.
cmis-page:page-num:: A base YANG identity for the number of the target CMIS page. The value is selected from 0 to 255.
cmis-page:bank:: A base YANG identity for the bank corresponding to the target CMIS page.
cmis-page:page-access-type:: A base YANG identity for access type of the target CMIS page. An access type is selected from among rw (A readable and writable element), rww (A readable and writable element that can be modified by the module), ro (A read-only element), wo(A write-only element), wo/sc (A write-only element with self-clearing side effect), and ro/cor (A write-only element with clean-on-read side effect).
cmis-page:description:: A base YANG identity for the description about the content of the target CMIS page.
cmis-page:value:: A base YANG identity for the subject area to be controlled.
value:offset: A base YANG identity for the location of the data within about the target CMIS page. The value is selected from 0 to 255.
value:size: A base YANG identity for the size of the value. The value is selected from 1 to 128.
value:value-access-type:: A base YANG identity for access type of the value. An access type is selected from among rw, rww, ro, wo, wo/sc, and ro/cor.
value:value-data: A base YANG identity for the data contained into the value. The data format is basically binary, but any other format (e.g., ASCII, JIS) can be also used. The length of the value must be the same with the indicated size. The value is writable only when the access-type is neither ro or ro/cor. In case that the value is across multiple subject areas which have different access-types, all access-type conditions must be satisfied. For example, if the value across subject-areas whose access-types are ro and rw, the access-type of the value is ro. When all conditions cannot be satisfied (e.g., ro and wo co-exists), an error should be responded.
value:description: A base YANG identity for the description of the value.

Note that the values related to CMIS pages are defined in .

The ietf-cmis-control is defined as an extension to ietf-interfaces.

file "ietf-cmis-control.yang" module ietf-cmis-control { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-cmis-control"; prefix cmis-ctrl; import ietf-interfaces { prefix if; } organization "IETF CCAMP Working Group"; contact "WG Web: WG List: Editor: Shunsuke Homma Editor: Hitoshi Irino "; description "This YANG module defines a data model for the management of CMIS (Common Management Interface Specification) pages as specified by OIF. It enables configuration and retrieval of CMIS page data, including access types and value fields, to support the management of pluggable optical modules via NETCONF or RESTCONF. Copyright (c) 2025 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 Revised 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 (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices."; // RFC Ed.: replace XXXX with actual RFC number and remove this note revision "2025-04-21" { description "Initial revision."; reference "I-D.hi-ccamp-cmis-control-yang-00"; } /* * CMIS control data nodes */ typedef access-type { type enumeration { enum rw { description "A readable and writable element."; } enum rww { description "A readable and writable element that can be modified by the module."; } enum ro { description "A read-only element."; } enum wo { description "A write-only element."; } enum wo/sc { description "A write-only element with self-clearing side effect."; } enum ro/cor { description "A write-only element with celan-on-read side effect."; } } description "Defines access types for CMIS elements."; } grouping cmis-page { description "Parameters stored in the CMIS page"; leaf page-num{ type uint8 { range "0 .. 255"; } mandatory true; description "The number of the CMIS page."; } leaf bank { type uint8; mandatory true; description "The banks corresponding to the CMIS page."; } leaf page-access-type { type access-type; config false; description "Access type of the CMIS page."; } leaf description { type string; description "The description of the CMIS page."; } list value { key "offset"; description "The value contained in the CMIS page."; leaf offset { type uint8; mandatory true; description "The memory address of the value."; } leaf size { type uint8 { range "1 .. 128"; } mandatory true; description "The memory size of the value."; } leaf value-access-type { type access-type; config false; description "Access type of the target value."; } leaf value-data { type binary; mandatory true; description "The data contained in the value. It is writable only when the access-type is not Read-Only or Read-Only with clean-on-read side effect."; } leaf description { type string; description "The description of the value."; } } } grouping cmis-pages { description "The list of the accessible CMIS pages supported by the pluggable device accommodated into the interface."; list cmis-page { key "page-num"; uses cmis-page; } } grouping cmis-control { description "Parameters for primitive CMIS control of the pluggable device equipped in the interface."; leaf cmis-enabled { type boolean; default "false"; config false; description "The availability of the CMIS for control the pluggable device equipped in the interface. If the device does not support CMIS, this value is false."; } leaf cmis-version { type string; config false; description "The version of the CMIS by the pluggable device."; } uses cmis-pages; } /* * Augment Interface */ augment "/if:interfaces/if:interface" { container cmis-control { uses cmis-control; } } }

]]>



  
  
  This section provides a more primitive YANG data model for CMIS access and control. 
  This is called as "Primitive Mode" and it doesn't manage supplemental information, 
  such as access-types or description, of the fields in a CMIS page, and treat accessed 
  memories as flat data structure.
  
  
  
  This mode enables implementation of client side be simple, but on the other hand, 
  server side is needed strict management of data of CMIS pages. For example, when a 
  server is changing any value, the server need to comprehend the page number, the 
  offset, and the data size in which the data is contained.
  

    
    
    The name of data node and prefix are described in . 
    This module is also an augment to the ietf-interface.
    


      Prefix
      YANG module
      Reference
      if
      ietf-interfaces
      
      cmis-ctrl-pm
      ietf-cmis-control-primitive
      RFC YYYY


      
      The tree diagram of ietf-cmis-control-primitive is shown below:
      

      

      
      
      The ietf-cmis-control-primitive is also defined as an extension to ietf-interfaces.
      

 file "ietf-cmis-control-primitive.yang"
module ietf-cmis-control-primitive {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-cmis-control-primitive";
  prefix cmis-ctrl-pm;

  import ietf-interfaces {
    prefix if;
  }

  organization
    "IETF CCAMP Working Group";

  contact
    "WG Web:   
    WG List:  

    Editor:   Shunsuke Homma
      
    
    Editor:   Hitoshi Irino
      ";

  description
    "This YANG module defines a primitive data model for the 
    management of CMIS (Common Management Interface Specification) 
    pages as specified by OIF. It enables configuration and 
    retrieval of CMIS page data, including access types and value 
    fields, to support the management of pluggable optical modules 
    via NETCONF or RESTCONF.

    Copyright (c) 2025 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 Revised
    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
    (https://www.rfc-editor.org/info/rfc YYYY); see the RFC itself
    for full legal notices.";
  
// RFC Ed.: replace XXXX with actual RFC number and remove this note

  revision "2025-04-21" {
    description
      "Initial revision.";
    reference
      "I-D.hi-ccamp-cmis-control-yang-00";
  }

  /*
   * Primitive Mode of CMIS control data nodes
   */

  grouping primitive-cmis-page {
    description
      "Parameters stored in the CMIS page as flat data structure";

    leaf page-num{
      type uint8 {
        range "0 .. 255";
      }
      mandatory true;
      description 
        "The number of the CMIS page.";
    }
    
    leaf bank {
      type uint8;
      mandatory true;
      description
        "The banks corresponding to the CMIS page.";
    }

      
    leaf offset {
      type uint8;
      mandatory true;
      description 
        "The memory address of the value.";
    }

    leaf size {
      type uint8 {
        range "1 .. 128";
      }
      mandatory true;
      description 
        "The memory size of the value.";
    }

    leaf value {
      type binary;
      mandatory true;
      description 
        "The actual data to write to the CMIS memory.";
    }
  }

  grouping cmis-control-primitive {
    description
      "Parameters for primitive CMIS control of the pluggable 
      device equipped in the interface.";
    
    leaf cmis-enabled {
      type boolean;
      default "false";
      config false;
      description
        "The availability of the CMIS for control the pluggable 
        device equipped in the interface. If the device does not 
        support CMIS, this value is false.";
    }
    
    leaf cmis-version {
      type string;
      config false;
      description
        "The version of the CMIS by the pluggable device.";
    }

    list primitive-cmis-page {
      key "page-num";
      config true;
      uses primitive-cmis-page;
    }
  }
  
  /*
   * Augment Interface
   */
  
  augment "/if:interfaces/if:interface" {
    container cmis-control-primitive {
      uses cmis-control-primitive;
    }
  }
}

]]>


    

  


  

  
  
  This YANG allows remote systems to control the equipped pluggable devices directly. 
  It might cause conflict of management of the pluggable devices among the platform node 
  and remote systems. For avoiding this problem, only the minimum necessary CMIS pages 
  (e.g., custom pages) should be exposed to external by using access control features 
  such as .
  

  
  Regarding to use of the primitive mode, the control rights of the accessible pages 
  are delegated to a controller. Therefore, it is recommended that the mode is used 
  in case that the controller can be trusted, for example, the controlled device and 
  controller are managed by the same operator. Otherwise, specific pages which 
  may affect on data plane signaling should not exposed by using access control features 
  such as 
  

  

  
  
  IANA Considerations

  
  This document requests IANA to register the following YANG modules in
  the "YANG Module Names" registry [RFC6020] within the "YANG Parameters" registry group.
  
  
  

    

  
    RFC Editor Note: Please replace XXXX and YYYY with the RFC number assigned to this document and remove this note.