    Internet Engineering Task Force (IETF)                   J. Ahlberg, Ed.
    Request for Comments: 8432                                   Ericsson AB
    Category: Informational                                       M. Ye, Ed.
    ISSN: 2070-1721                                      Huawei Technologies
                                                                       X. Li
                                                     NEC Laboratories Europe
                                                               LM. Contreras
                                                              Telefonica I+D
                                                               CJ. Bernardos
                                            Universidad Carlos III de Madrid
                                                                October 2018

                   A Framework for Management and Control of
               Microwave and Millimeter Wave Interface Parameters

    Abstract

       The unification of control and management of microwave radio link
       interfaces is a precondition for seamless multi-layer networking and
       automated network provisioning and operation.

       This document describes the required characteristics and use cases
       for control and management of radio link interface parameters using a
       YANG data model.

       The purpose is to create a framework to identify the necessary
       information elements and define a YANG data model for control and
       management of the radio link interfaces in a microwave node.  Some
       parts of the resulting model may be generic and could also be used by
       other technologies, e.g., Ethernet technology.

    Status of This Memo

       This document is not an Internet Standards Track specification; it is
       published for informational purposes.

       This document is a product of the Internet Engineering Task Force
       (IETF).  It represents the consensus of the IETF community.  It has
       received public review and has been approved for publication by the
       Internet Engineering Steering Group (IESG).  Not all documents
       approved by the IESG are candidates for any level of Internet
       Standard; see Section 2 of RFC 7841.

       Information about the current status of this document, any errata,
       and how to provide feedback on it may be obtained at
       https://www.rfc-editor.org/info/rfc8432.

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    Copyright Notice

       Copyright (c) 2018 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.

    Table of Contents

       1. Introduction ....................................................3
          1.1. Conventions Used in This Document ..........................5
       2. Terminology and Definitions .....................................5
       3. Approaches to Manage and Control Radio Link Interfaces ..........7
          3.1. Network Management Solutions ...............................7
          3.2. Software-Defined Networking ................................7
       4. Use Cases .......................................................8
          4.1. Configuration Management ...................................9
          4.2. Inventory .................................................10
          4.3. Status and Statistics .....................................10
          4.4. Performance Management ....................................10
          4.5. Fault Management ..........................................11
          4.6. Troubleshooting and Root Cause Analysis ...................11
       5. Requirements ...................................................11
       6. Gap Analysis on Models .........................................12
          6.1. Microwave Radio Link Functionality ........................13
          6.2. Generic Functionality .....................................14
          6.3. Summary ...................................................15
       7. Security Considerations ........................................16
       8. IANA Considerations ............................................16
       9. References .....................................................16
          9.1. Normative References ......................................16
          9.2. Informative References ....................................17
       Contributors ......................................................19
       Authors' Addresses ................................................20

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    1.  Introduction

       Microwave radio is a technology that uses high-frequency radio waves
       to provide high-speed wireless connections that can send and receive
       voice, video, and data information.  It is a general term used for
       systems covering a very large range of traffic capacities, channel
       separations, modulation formats, and applications over a wide range
       of frequency bands from 1.4 GHz up to and above 100 GHz.

       The main application for microwave is backhaul for mobile broadband.
       Those networks will continue to be modernized using a combination of
       microwave and fiber technologies.  The choice of technology depends
       on fiber presence and cost of ownership, not capacity limitations in
       microwave.

       Today, microwave is already able to fully support the capacity needs
       of a backhaul in a radio access network and will evolve to support
       multiple gigabits in traditional frequency bands and more than 10
       gigabits in higher-frequency bands with more bandwidth.  Layer 2 (L2)
       Ethernet features are normally an integrated part of microwave nodes,
       and more advanced L2 and Layer 3 (L3) features will be introduced
       over time to support the evolution of the transport services that
       will be provided by a backhaul/transport network.  Note that wireless
       access technologies such as 3/4/5G and Wi-Fi are not within the scope
       of this document.

       Open and standardized interfaces are a prerequisite for efficient
       management of equipment from multiple vendors, integrated in a single
       system/controller.  This framework addresses management and control
       of the radio link interface(s) and their relationship to other
       interfaces (typically, Ethernet interfaces) in a microwave node.  A
       radio link provides the transport over the air, using one or several
       carriers in aggregated or protected configurations.  Managing and
       controlling a transport service over a microwave node involves both
       radio link and packet transport functionality.

       Today, there are already numerous IETF data models, RFCs, and
       Internet-Drafts with technology-specific extensions that cover a
       large part of the L2 and L3 domains.  Examples include IP Management
       [RFC8344], Routing Management [RFC8349], and Provider Bridge
       [IEEE802.1Qcp].  These are based on the IETF YANG data model for
       Interface Management [RFC8343], which is an evolution of the SNMP
       IF-MIB [RFC2863].

       Since microwave nodes will contain more and more L2 and L3 (packet)
       functionality that is expected to be managed using those models,
       there are advantages if radio link interfaces can be modeled and
       managed using the same structure and the same approach.  This is

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       especially true for use cases in which a microwave node is managed as
       one common entity that includes both the radio link and the L2 and L3
       functionality, e.g., basic configuration of the node and connections,
       centralized troubleshooting, upgrade, and maintenance.  All
       interfaces in a node, irrespective of technology, would then be
       accessed from the same core model, i.e., [RFC8343], and could be
       extended with technology-specific parameters in models augmenting
       that core model.  The relationship/connectivity between interfaces
       could be given by the physical equipment configuration.  For example,
       the slot where the Radio Link Terminal (modem) is plugged in could be
       associated with a specific Ethernet port due to the wiring in the
       backplane of the system, or it could be flexible and therefore
       configured via a management system or controller.

       +------------------------------------------------------------------+
       | Interface [RFC8343]                                              |
       |                +---------------+                                 |
       |                | Ethernet Port |                                 |
       |                +---------------+                                 |
       |                      \                                           |
       |                    +---------------------+                       |
       |                    | Radio Link Terminal |                       |
       |                    +---------------------+                       |
       |                       /              \                           |
       |     +---------------------+       +---------------------+        |
       |     | Carrier Termination |       | Carrier Termination |        |
       |     +---------------------+       +---------------------+        |
       +------------------------------------------------------------------+

                Figure 1: Relationship between Interfaces in a Node

       There will always be certain implementations that differ among
       products, so it is practically impossible to achieve industry
       consensus on every design detail.  It is therefore important to focus
       on the parameters that are required to support the use cases
       applicable for centralized, unified, multi-vendor management and to
       allow other parameters to either be optional or be covered by
       extensions to the standardized model.  Furthermore, a standard that
       allows for a certain degree of freedom encourages innovation and
       competition, which benefits the entire industry.  Thus, it is
       important that a radio link management model covers all relevant
       functions but also leaves room for product- and feature-specific
       extensions.

       Models are available for microwave radio link functionality:
       "Microwave Information Model" by the ONF [ONF-MW] and "Microwave
       Radio Link YANG Data Models" submitted to and discussed by the CCAMP
       Working Group [CCAMP-MW].  The purpose of this document is to reach

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       consensus within the industry around one common approach with respect
       to the use cases and requirements to be supported, the type and
       structure of the model, and the resulting attributes to be included.
       This document describes the use cases, requirements, and expected
       characteristics of the model.  It also includes an analysis of how
       the models in the two ongoing initiatives fulfill these expectations
       and recommendations for what can be reused and what gaps need to be
       filled by a new and evolved model ("A YANG Data Model for Microwave
       Radio Link" by the IETF [IETF-MW]).

    1.1.  Conventions Used in This Document

       The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
       "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
       "OPTIONAL" in this document are to be interpreted as described in
       BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
       capitals, as shown here.

    2.  Terminology and Definitions

       Microwave radio:  a term commonly used for technologies that operate
          in both microwave and millimeter wavelengths and in frequency
          bands from 1.4 GHz up to and beyond 100 GHz.  In traditional
          bands, it typically supports capacities of 1-3 Gbps; in the 70/80
          GHz band, it supports up to 10 Gbps.  Using multi-carrier systems
          operating in frequency bands with wider channels, the technology
          will be capable of providing capacities of up to 100 Gbps.

       Microwave radio technology:  widely used for point-to-point
          telecommunications because its small wavelength allows
          conveniently sized antennas to direct radio waves in narrow beams
          and its comparatively higher frequencies allow broad bandwidth and
          high data-transmission rates.  It is used for a broad range of
          fixed and mobile services, including high-speed, point-to-point
          wireless local area networks (WLANs) and broadband access.

          The ETSI EN 302 217 series defines the characteristics and
          requirements of microwave equipment and antennas.  In particular,
          ETSI EN 302 217-2 [EN302217-2] specifies the essential parameters
          for the systems operating from 1.4 GHz to 86 GHz.

       Carrier Termination and Radio Link Terminal:  two concepts defined to
          support modeling of microwave radio link features and parameters
          in a structured yet simple manner.

          *  Carrier Termination: an interface for the capacity provided
             over the air by a single carrier.  It is typically defined by
             its transmitting and receiving frequencies.

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          *  Radio Link Terminal: an interface providing Ethernet capacity
             and/or Time Division Multiplexing (TDM) capacity to the
             associated Ethernet and/or TDM interfaces in a node.  It is
             used for setting up a transport service over a microwave radio
             link.

          Figure 2 provides a graphical representation of the Carrier
          Termination and Radio Link Terminal concepts.

                     /--------- Radio Link ---------\
                      Near End              Far End

               +---------------+           +---------------+
               |    Radio Link |           | Radio Link    |
               |      Terminal |           | Terminal      |
               |               |           |               |
               |           (Protected or Bonded)           |
               |               |           |               |
               | +-----------+ |           | +-----------+ |
               | |           | | Carrier A | |           | |
               | |  Carrier  | |<--------->| |  Carrier  | |
               | |Termination| |           | |Termination| |
        ETH----| |           | |           | |           | |----ETH
               | +-----------+ |           | +-----------+ |
        TDM----|               |           |               |----TDM
               | +-----------+ |           | +-----------+ |
               | |           | | Carrier B | |           | |
               | |  Carrier  | |<--------->| |  Carrier  | |
               | |Termination| |           | |Termination| |
               | |           | |           | |           | |
               | +-----------+ |           | +-----------+ |
               |               |           |               |
               +---------------+           +---------------+

         \--- Microwave Node ---/          \--- Microwave Node ---/

               Figure 2: Radio Link Terminal and Carrier Termination

       Software-Defined Networking (SDN):  an architecture that decouples
          the network control and forwarding functions, enabling the network
          control to become directly programmable and the underlying
          infrastructure to be abstracted for applications and network
          services.  SDN can be used for automation of traditional network
          management functionality using an SDN approach of standardized
          programmable interfaces for control and management [RFC7426].

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    3.  Approaches to Manage and Control Radio Link Interfaces

       This framework addresses the definition of an open and standardized
       interface for radio link functionality in a microwave node.  The
       application of such an interface used for management and control of
       nodes and networks typically varies from one operator to another in
       terms of the systems used and how they interact.  Possible approaches
       include using a Network Management System (NMS), Software-Defined
       Networking (SDN), or some combination of the two.  As there are still
       many networks where the NMS is implemented as one component/interface
       and the SDN controller is scoped to control-plane functionality as a
       separate component/interface, this document does not preclude either
       model.  The aim of this document is to provide a framework for
       development of a common YANG data model for both management and
       control of microwave interfaces.

    3.1.  Network Management Solutions

       The classic network management solutions, with vendor-specific domain
       management combined with cross-domain functionality for service
       management and analytics, still dominate the market.  These solutions
       are expected to evolve and benefit from an increased focus on
       standardization by simplifying multi-vendor management and removing
       the need for vendor- or domain-specific management.

    3.2.  Software-Defined Networking

       One of the main drivers for applying SDN from an operator perspective
       is simplification and automation of network provisioning as well as
       end-to-end network service management.  The vision is to have a
       global view of the network conditions spanning different vendors'
       equipment and multiple technologies.

       If nodes from different vendors are managed by the same SDN
       controller via a node management interface without the extra effort
       of introducing intermediate systems, all nodes must align their node
       management interfaces.  Hence, an open and standardized node
       management interface is required in a multi-vendor environment.  Such
       a standardized interface enables unified management and configuration
       of nodes from different vendors by a common set of applications.

       In addition to SDN applications for configuring, managing, and
       controlling the nodes and their associated transport interfaces
       (including the L2 Ethernet, L3 IP, and radio interfaces), there are
       also a large variety of more advanced SDN applications that can be
       utilized and/or developed.

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       A potentially flexible approach for operators is to use SDN in a
       logically controlled way, managing the radio links by selecting a
       predefined operation mode.  The operation mode is a set of logical
       metrics or parameters describing a complete radio link configuration,
       such as capacity, availability, priority, and power consumption.

       An example of an operation mode table is shown in Figure 3.  Based on
       its operation policy (e.g., power consumption or traffic priority),
       the SDN controller selects one operation mode and translates that
       into the required configuration of the individual parameters for the
       Radio Link Terminals and the associated Carrier Terminations.

       +----+---------------+------------+-------------+-----------+------+
       | ID |Description    | Capacity   |Availability | Priority  |Power |
       +----+---------------+------------+-------------+-----------+------+
       | 1  |High capacity  |  400 Mbps  |  99.9%      | Low       |High  |
       +----+---------------+------------+-------------+-----------+------+
       | 2  |High avail-    |  100 Mbps  |  99.999%    | High      |Low   |
       |    | ability       |            |             |           |      |
       +----+---------------+------------+-------------+-----------+------+

                   Figure 3: Example of an Operation Mode Table

       An operation mode bundles together the values of a set of different
       parameters.  How each operation mode maps a certain set of attributes
       is out of the scope of this document.

    4.  Use Cases

       The use cases described should be the basis for identifying and
       defining the parameters to be supported by a YANG data model for
       management of radio links that will be applicable to centralized,
       unified, multi-vendor management.  The use cases involve
       configuration management, inventory, status and statistics,
       performance management, fault management, and troubleshooting and
       root cause analysis.

       Other product-specific use cases, e.g., addressing installation or
       on-site troubleshooting and fault resolution, are outside the scope
       of this framework.  If required, these use cases are expected to be
       supported by product-specific extensions to the standardized model.

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    4.1.  Configuration Management

       Configuration management involves configuring a Radio Link Terminal,
       the constituent Carrier Terminations, and, when applicable, the
       relationship to IP/Ethernet and TDM interfaces.

       o  Understand the capabilities and limitations

          Exchange of information between a manager and a device about the
          capabilities supported and specific limitations in the parameter
          values and enumerations that can be used.

          Examples of information that could be exchanged include the
          maximum modulation supported and support (or lack of support) for
          the Cross Polarization Interference Cancellation (XPIC) feature.

       o  Initial Configuration

          Initial configuration of a Radio Link Terminal, enough to
          establish Layer 1 (L1) connectivity to an associated Radio Link
          Terminal on a device at the far end over the hop.  It may also
          include configuration of the relationship between a Radio Link
          Terminal and an associated traffic interface, e.g., an Ethernet
          interface, unless that is given by the equipment configuration.

          Frequency, modulation, coding, and output power are examples of
          parameters typically configured for a Carrier Termination and type
          of aggregation/bonding or protection configurations expected for a
          Radio Link Terminal.

       o  Radio link reconfiguration and optimization

          Reconfiguration, update, or optimization of an existing Radio Link
          Terminal.  Output power and modulation for a Carrier Termination
          as well as protection schemas and activation/deactivation of
          carriers in a Radio Link Terminal are examples on parameters that
          can be reconfigured and used for optimization of the performance
          of a network.

       o  Radio link logical configuration

          Radio Link Terminals configured to include a group of carriers are
          widely used in microwave technology.  There are several kinds of
          groups: aggregation/bonding, 1+1 protection/redundancy, etc.  To
          avoid configuration on each Carrier Termination directly, a
          logical control provides flexible management by mapping a logical
          configuration to a set of physical attributes.  This could also be

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          applied in a hierarchical SDN environment where some domain
          controllers are located between the SDN controller and the Radio
          Link Terminal.

    4.2.  Inventory

       o  Retrieve logical inventory and configuration from device

          Request from manager and response by device with information about
          radio interfaces, e.g., their constitution and configuration.

       o  Retrieve physical/equipment inventory from device

          Request from manager about physical and/or equipment inventory
          associated with the Radio Link Terminals and Carrier Terminations.

    4.3.  Status and Statistics

       o  Actual status and performance of a radio link interface

          Manager requests and device responds with information about actual
          status and statistics of configured radio link interfaces and
          their constituent parts.  It's important to report the effective
          bandwidth of a radio link since it can be configured to
          dynamically adjust the modulation based on the current signal
          conditions.

    4.4.  Performance Management

       o  Configuration of historical performance measurements

          Configuration of historical performance measurements for a radio
          link interface and/or its constituent parts.  See Section 4.1.

       o  Collection of historical performance data

          Collection of historical performance data in bulk by the manager
          is a general use case for a device and not specific to a radio
          link interface.

          Collection of an individual counter for a specific interval is in
          some cases required as a complement to the retrieval in bulk as
          described above.

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    4.5.  Fault Management

       o  Configuration of alarm reporting

          Configuration of alarm reporting associated specifically with
          radio interfaces, e.g., configuration of alarm severity, is a
          subset of the configuration use case to be supported.  See
          Section 4.1.

       o  Alarm management

          Alarm synchronization, visualization, handling, notifications, and
          events are generic use cases for a device and should be supported
          on a radio link interface.  There are, however, radio-specific
          alarms that are important to report.  Signal degradation of the
          radio link is one example.

    4.6.  Troubleshooting and Root Cause Analysis

       Provide information and suggest actions required by a manager/
       operator to investigate and understand the underlying issue to a
       problem in the performance and/or functionality of a Radio Link
       Terminal and the associated Carrier Terminations.

    5.  Requirements

       For managing a microwave node including both the radio link and the
       packet transport functionality, a unified data model is desired to
       unify the modeling of the radio link interfaces and the L2/L3
       interfaces using the same structure and the same modeling approach.
       If some part of the model is generic for other technology usage, it
       should be clearly stated.

       The purpose of the YANG data model is for management and control of
       the radio link interface(s) and the relationship/connectivity to
       other interfaces, typically to Ethernet interfaces, in a microwave
       node.

       The capability of configuring and managing microwave nodes includes
       the following requirements for the model:

       1.  It MUST be possible to configure, manage, and control a Radio
           Link Terminal and the constituent Carrier Terminations.

           A.  Configuration of frequency, channel bandwidth, modulation,
               coding, and transmitter output power MUST be supported for a
               Carrier Termination.

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           B.  A Radio Link Terminal MUST configure the associated Carrier
               Terminations and the type of aggregation/bonding or
               protection configurations expected for the Radio Link
               Terminal.

           C.  The capability (e.g., the maximum modulation supported) and
               the actual status/statistics (e.g., administrative status of
               the carriers) SHOULD also be supported by the data model.

           D.  The definition of the features and parameters SHOULD be based
               on established microwave equipment and radio standards, such
               as ETSI EN 302 217 [EN302217-2], which specifies the
               essential parameters for microwave systems operating from 1.4
               GHz to 86 GHz.

       2.  It MUST be possible to map different traffic types (e.g., TDM and
           Ethernet) to the transport capacity provided by a specific Radio
           Link Terminal.

       3.  It MUST be possible to configure and collect historical
           measurements (for the use case described in Section 4.4) to be
           performed on a radio link interface (e.g., minimum, maximum,
           average transmit power, and received level in dBm).

       4.  It MUST be possible to configure and retrieve alarms reporting
           associated with the radio interfaces (e.g., configuration fault,
           signal lost, modem fault, and radio fault).

    6.  Gap Analysis on Models

       The purpose of the gap analysis is to identify and recommend what
       models to use in a microwave device to support the use cases and
       requirements specified in the previous sections.  This document also
       makes a recommendation for how the gaps not supported should be
       filled, including the need for development of new models and
       evolution of existing models and documents.

       Models are available for microwave radio link functionality:
       "Microwave Information Model" by the ONF [ONF-MW] and "Microwave
       Radio Link YANG Data Models" submitted to and discussed by the CCAMP
       Working Group [CCAMP-MW].  The analysis in this document takes these
       initiatives into consideration and makes a recommendation on how to
       use and complement them in order to fill the gaps identified.

       For generic functionality, not functionality specific to radio link,
       the ambition is to refer to existing or emerging models that could be
       applicable for all functional areas in a microwave node.

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    6.1.  Microwave Radio Link Functionality

       [ONF-CIM] defines a CoreModel of the ONF Common Information Model.
       An information model describes the things in a domain in terms of
       objects, their properties (represented as attributes), and their
       relationships.  The ONF information model is expressed in Unified
       Modeling Language (UML).  The ONF CoreModel is independent of
       specific data-plane technology.  The technology-specific content,
       acquired in a runtime solution via "filled in" cases of
       specification, augments the CoreModel by providing a forwarding
       technology-specific representation.

       IETF data models define implementations and protocol-specific
       details.  YANG is a data modeling language used to model the
       configuration and state data.  [RFC8343] defines a generic YANG data
       model for interface management that doesn't include technology-
       specific information.  To describe the technology-specific
       information, several YANG data models have been proposed in the IETF
       to augment [RFC8343], e.g., the data model defined in [RFC8344].  The
       YANG data model is a popular approach for modeling interfaces for
       many packet transport technologies and is thereby well positioned to
       become an industry standard.  In light of this trend, [CCAMP-MW]
       provides a YANG data model proposal for radio interfaces that is well
       aligned with the structure of other technology-specific YANG data
       models augmenting [RFC8343].

       [RFC3444] explains the difference between Information Models (IMs)
       and Data Models (DMs).  An IM models managed objects at a conceptual
       level for designers and operators, while a DM is defined at a lower
       level and includes many details for implementers.  In addition, the
       protocol-specific details are usually included in a DM.  Since
       conceptual models can be implemented in different ways, multiple DMs
       can be derived from a single IM.

       It is recommended to use the structure of the model described in
       [CCAMP-MW] as the starting point, since it is a data model providing
       the wanted alignment with [RFC8343].  To cover the identified gaps,
       it is recommended to define new leafs/parameters and include those in
       the new model [IETF-MW] while taking reference from [ONF-CIM].  It is
       also recommended to add the required data nodes to describe the
       interface layering for the capacity provided by a Radio Link Terminal
       and the associated Ethernet and TDM interfaces in a microwave node.
       The principles and data nodes for interface layering described in
       [RFC8343] should be used as a basis.

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    6.2.  Generic Functionality

       For generic functionality, not functionality specific to radio links,
       the recommendation is to refer to existing RFCs or emerging Internet-
       Drafts according to Figure 4.  "[IETF-MW]" is used in Figure 4 for
       the cases where the functionality is recommended to be included in
       the new model [IETF-MW] as described in Section 6.1.

       +------------------------------------+-----------------------------+
       | Generic Functionality              | Recommendation              |
       |                                    |                             |
       +------------------------------------+-----------------------------+
       |1. Fault Management                 |                             |
       |                                    |                             |
       |   Alarm Configuration              | [IETF-MW]                   |
       |                                    |                             |
       |   Alarm Notifications/             | [YANG-ALARM]                |
       |   Synchronization                  |                             |
       +------------------------------------+-----------------------------+
       |2. Performance Management           |                             |
       |                                    |                             |
       |   Performance Configuration/       | [IETF-MW]                   |
       |   Activation                       |                             |
       |                                    |                             |
       |   Performance Collection           | [IETF-MW] and XML files     |
       +------------------------------------+-----------------------------+
       |3.  Physical/Equipment Inventory    | [RFC8348]                   |
       +------------------------------------+-----------------------------+

         Figure 4: Recommendation for How to Support Generic Functionality

       Microwave-specific alarm configurations are recommended to be
       included in the new model [IETF-MW] and could be based on what is
       supported in the models described in [ONF-MW] and [CCAMP-MW].  Alarm
       notifications and synchronization are general and are recommended to
       be supported by a generic model, such as [YANG-ALARM].

       Activation of interval counters and thresholds could be a generic
       function, but it is recommended to be supported by the new model
       [IETF-MW].  It can be based on the models described in [ONF-MW] and
       [CCAMP-MW].

       Collection of interval/historical counters is a generic function that
       needs to be supported in a node.  File-based collection via the SSH
       File Transfer Protocol (SFTP) and collection via NETCONF/YANG
       interfaces are two possible options; the recommendation is to include

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       support for the latter in the new model [IETF-MW].  The models
       described in [ONF-MW] and [CCAMP-MW] can also be used as a basis in
       this area.

       Physical and/or equipment inventory associated with the Radio Link
       Terminals and Carrier Terminations is recommended to be covered by a
       generic model for the complete node, e.g., the model defined in
       [RFC8348].  It is thereby outside the scope of the new model
       [IETF-MW].

    6.3.  Summary

       The conclusions and recommendations from the analysis can be
       summarized as follows:

       1.  A new YANG data model for radio link [IETF-MW] should be defined
           with enough scope to support the use cases and requirements in
           Sections 4 and 5 of this document.

       2.  Use the structure of the model described in [CCAMP-MW] as the
           starting point.  It augments [RFC8343] and is thereby as required
           aligned with the structure of the models for management of the L2
           and L3 domains.

       3.  Use established microwave equipment and radio standards (such as
           [EN302217-2], the model described in [CCAMP-MW], and the model
           described in [ONF-MW]) as the basis for the definition of the
           detailed leafs/ parameters to support the specified use cases and
           requirements, proposing new ones to cover identified gaps.

       4.  Add the required data nodes to describe the interface layering
           for the capacity provided by a Radio Link Terminal and the
           associated Ethernet and TDM interfaces, using the principles and
           data nodes for interface layering described in [RFC8343] as a
           basis.

       5.  Include support for configuration of microwave-specific alarms in
           the new YANG data model [IETF-MW] and rely on a generic model
           such as [YANG-ALARM] for notifications and alarm synchronization.

       6.  Use a generic model such as [RFC8348] for physical/equipment
           inventory.

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    7.  Security Considerations

       The configuration information may be considered sensitive or
       vulnerable in network environments.  Unauthorized access to
       configuration data nodes can have a negative effect on network
       operations, e.g., interrupting the ability to forward traffic or
       increasing the interference level of the network.  The status and
       inventory reveal some network information that could be very helpful
       to an attacker.  A malicious attack to that information may result in
       a loss of customer data.  Security issues concerning the access
       control to management interfaces can be generally addressed by
       authentication techniques providing origin verification, integrity,
       and confidentiality.  In addition, management interfaces can be
       physically or logically isolated by configuring them to be only
       accessible out-of-band, through a system that is physically or
       logically separated from the rest of the network infrastructure.  In
       cases where management interfaces are accessible in-band at the
       client device or within the microwave transport network domain,
       filtering or firewalling techniques can be used to restrict
       unauthorized in-band traffic.  Additionally, authentication
       techniques may be used in all cases.

       This framework describes the requirements and characteristics of a
       YANG data model for control and management of the radio link
       interfaces in a microwave node.  It is supposed to be accessed via a
       management protocol with a secure transport layer, such as NETCONF
       [RFC6241].

    8.  IANA Considerations

       This document has no IANA actions.

    9.  References

    9.1.  Normative References

       [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
                  Requirement Levels", BCP 14, RFC 2119,
                  DOI 10.17487/RFC2119, March 1997,
                  <https://www.rfc-editor.org/info/rfc2119>.

       [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
                  2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
                  May 2017, <https://www.rfc-editor.org/info/rfc8174>.

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    9.2.  Informative References

       [CCAMP-MW] Ahlberg, J., Carlson, J-O., Lund, H-A., Olausson, T.,
                  Ye, M., and M. Vaupotic, "Microwave Radio Link YANG Data
                  Models", Work in Progress, draft-ahlberg-ccamp-microwave-
                  radio-link-01, May 2016.

       [EN302217-2]
                  ETSI, "Fixed Radio Systems; Characteristics and
                  requirements for point-to-point equipment and antennas;
                  Part 2: Digital systems operating in frequency bands from
                  1 GHz to 86 GHz; Harmonised Standard covering the
                  essential requirements of article 3.2 of Directive
                  2014/53/EU", ETSI EN 302 217-2, V3.1.1, May 2017.

       [IEEE802.1Qcp]
                  IEEE, "Bridges and Bridged Networks Ammendment: YANG Data
                  Model", Work in Progress, Draft 2.2, March 2018,
                  <https://1.ieee802.org/tsn/802-1qcp/>.

       [IETF-MW]  Ahlberg, J., Ye, M., Li, X., Spreafico, D., and
                  M. Vaupotic, "A YANG Data Model for Microwave Radio Link",
                  Work in Progress, draft-ietf-ccamp-mw-yang-10, October
                  2018.

       [ONF-CIM]  ONF, "Core Information Model (CoreModel)", ONF
                  TR-512, version 1.2, September 2016,
                  <https://www.opennetworking.org/images/stories/downloads/
                  sdn-resources/technical-reports/
                  TR-512_CIM_(CoreModel)_1.2.zip>.

       [ONF-MW]   ONF, "Microwave Information Model", ONF TR-532, version
                  1.0, December 2016,
                  <https://www.opennetworking.org/images/stories/downloads/
                  sdn-resources/technical-reports/
                  TR-532-Microwave-Information-Model-V1.pdf>.

       [RFC2863]  McCloghrie, K. and F. Kastenholz, "The Interfaces Group
                  MIB", RFC 2863, DOI 10.17487/RFC2863, June 2000,
                  <https://www.rfc-editor.org/info/rfc2863>.

       [RFC3444]  Pras, A. and J. Schoenwaelder, "On the Difference between
                  Information Models and Data Models", RFC 3444,
                  DOI 10.17487/RFC3444, January 2003,
                  <https://www.rfc-editor.org/info/rfc3444>.

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    RFC 8432                   Microwave Framework              October 2018

       [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,
                  <https://www.rfc-editor.org/info/rfc6241>.

       [RFC7426]  Haleplidis, E., Ed., Pentikousis, K., Ed., Denazis, S.,
                  Hadi Salim, J., Meyer, D., and O. Koufopavlou, "Software-
                  Defined Networking (SDN): Layers and Architecture
                  Terminology", RFC 7426, DOI 10.17487/RFC7426, January
                  2015, <https://www.rfc-editor.org/info/rfc7426>.

       [RFC8343]  Bjorklund, M., "A YANG Data Model for Interface
                  Management", RFC 8343, DOI 10.17487/RFC8343, March 2018,
                  <https://www.rfc-editor.org/info/rfc8343>.

       [RFC8344]  Bjorklund, M., "A YANG Data Model for IP Management",
                  RFC 8344, DOI 10.17487/RFC8344, March 2018,
                  <https://www.rfc-editor.org/info/rfc8344>.

       [RFC8348]  Bierman, A., Bjorklund, M., Dong, J., and D. Romascanu, "A
                  YANG Data Model for Hardware Management", RFC 8348,
                  DOI 10.17487/RFC8348, March 2018,
                  <https://www.rfc-editor.org/info/rfc8348>.

       [RFC8349]  Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for
                  Routing Management (NMDA Version)", RFC 8349,
                  DOI 10.17487/RFC8349, March 2018,
                  <https://www.rfc-editor.org/info/rfc8349>.

       [YANG-ALARM]
                  Vallin, S. and M. Bjorklund, "YANG Alarm Module", Work in
                  Progress, draft-ietf-ccamp-alarm-module-04, October 2018.

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    Contributors

       Marko Vaupotic
       Aviat Networks
       Motnica 9
       Trzin-Ljubljana  1236
       Slovenia

       Email: Marko.Vaupotic@aviatnet.com

       Jeff Tantsura

       Email: jefftant.ietf@gmail.com

       Koji Kawada
       NEC Corporation
       1753, Shimonumabe Nakahara-ku
       Kawasaki, Kanagawa 211-8666
       Japan

       Email: k-kawada@ah.jp.nec.com

       Ippei Akiyoshi
       NEC
       1753, Shimonumabe Nakahara-ku
       Kawasaki, Kanagawa 211-8666
       Japan

       Email: i-akiyoshi@ah.jp.nec.com

       Daniela Spreafico
       Nokia - IT
       Via Energy Park, 14
       Vimercate (MI)  20871
       Italy

       Email: daniela.spreafico@nokia.com

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    Authors' Addresses

       Jonas Ahlberg (editor)
       Ericsson AB
       Lindholmspiren 11
       Goteborg  417 56
       Sweden

       Email: jonas.ahlberg@ericsson.com

       Min Ye (editor)
       Huawei Technologies
       No.1899, Xiyuan Avenue
       Chengdu  611731
       China

       Email: amy.yemin@huawei.com

       Xi Li
       NEC Laboratories Europe
       Kurfuersten-Anlage 36
       Heidelberg  69115
       Germany

       Email: Xi.Li@neclab.eu

       Luis Contreras
       Telefonica I+D
       Ronda de la Comunicacion, S/N
       Madrid  28050
       Spain

       Email: luismiguel.contrerasmurillo@telefonica.com

       Carlos J. Bernardos
       Universidad Carlos III de Madrid
       Av. Universidad, 30
       Madrid, Leganes  28911
       Spain

       Email: cjbc@it.uc3m.es

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