RFC 8532
Generic YANG Data Model for the Management of Operations, Administration, and Maintenance (OAM) Protocols That Use Connectionless Communications
Internet Engineering Task Force (IETF) D. Kumar Request for Comments: 8532 Cisco Category: Standards Track M. Wang ISSN: 2070-1721 Q. Wu, Ed. Huawei R. Rahman S. Raghavan Cisco April 2019 Generic YANG Data Model for the Management of Operations, Administration, and Maintenance (OAM) Protocols That Use Connectionless CommunicationsAbstract
This document presents a base YANG Data model for the management of Operations, Administration, and Maintenance (OAM) protocols that use connectionless communications. The data model is defined using the YANG data modeling language, as specified in RFC 7950. It provides a technology-independent abstraction of key OAM constructs for OAM protocols that use connectionless communication. The base model presented here can be extended to include technology-specific details. There are two key benefits of this approach: First, it leads to uniformity between OAM protocols. Second, it supports both nested OAM workflows (i.e., performing OAM functions at the same level or different levels through a unified interface) as well as interactive OAM workflows (i.e., performing OAM functions at the same level through a unified interface). Status of This Memo This is an Internet Standards Track document. 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). Further information on Internet Standards is available in 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/rfc8532.
Copyright Notice Copyright (c) 2019 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 2. Conventions Used in This Document . . . . . . . . . . . . . . 4 2.1. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5 2.3. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 5 3. Overview of the Connectionless OAM Model . . . . . . . . . . 5 3.1. TP Address . . . . . . . . . . . . . . . . . . . . . . . 6 3.2. Tools . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.3. OAM Neighboring Test Points . . . . . . . . . . . . . . . 7 3.4. Test Point Location Information . . . . . . . . . . . . . 8 3.5. Test Point Locations . . . . . . . . . . . . . . . . . . 8 3.6. Path Discovery Data . . . . . . . . . . . . . . . . . . . 8 3.7. Continuity Check Data . . . . . . . . . . . . . . . . . . 9 3.8. OAM Data Hierarchy . . . . . . . . . . . . . . . . . . . 9 4. LIME Time Types YANG Module . . . . . . . . . . . . . . . . . 12 5. Connectionless OAM YANG Module . . . . . . . . . . . . . . . 15 6. Connectionless Model Applicability . . . . . . . . . . . . . 44 6.1. BFD Extension . . . . . . . . . . . . . . . . . . . . . . 45 6.1.1. Augment Method . . . . . . . . . . . . . . . . . . . 45 6.1.2. Schema Mount . . . . . . . . . . . . . . . . . . . . 47 6.2. LSP Ping Extension . . . . . . . . . . . . . . . . . . . 49 6.2.1. Augment Method . . . . . . . . . . . . . . . . . . . 49 6.2.2. Schema Mount . . . . . . . . . . . . . . . . . . . . 50 7. Security Considerations . . . . . . . . . . . . . . . . . . . 52 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 54 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 54 9.1. Normative References . . . . . . . . . . . . . . . . . . 54 9.2. Informative References . . . . . . . . . . . . . . . . . 56 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 58 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 59
1. Introduction
Operations, Administration, and Maintenance (OAM) are important networking functions that allow operators to: 1. monitor network communications (i.e., reachability verification and Continuity Check) 2. troubleshoot failures (i.e., fault verification and localization) 3. monitor service-level agreements and performance (i.e., performance management) An overview of OAM tools is presented in [RFC7276]. Ping and Traceroute (see [RFC792] and [RFC4443]) are respectively well-known fault verification and isolation tools for IP networks. Over the years, different technologies have developed similar toolsets for equivalent purposes. The different sets of OAM tools may support both connection-oriented or connectionless technologies. In connection-oriented technologies, a connection is established prior to the transmission of data. After the connection is established, no additional control information such as signaling or operations and maintenance information is required to transmit the actual user data. In connectionless technologies, data is typically sent between communicating endpoints without prior arrangement, but control information is required to identify the destination (e.g., [G.800] and [RFC7276]). The YANG data model for OAM protocols using connection-oriented communications is specified in [RFC8531]. This document defines a base YANG data model for OAM protocols that use connectionless communications. The data model is defined using the YANG data modeling language [RFC7950]. This generic YANG data model for connectionless OAM includes only configuration and state data. It can be used in conjunction with the data retrieval method model described in [RFC8533], which focuses on the data retrieval procedures such as RPC, or it can be used independently of this data retrieval method model.
2. Conventions Used in This Document
The following terms are defined in [RFC6241] and are used in this specification: o client o configuration data o server o state data The following terms are defined in [RFC7950] and are used in this specification: o augment o data model o data node The terminology for describing YANG data models is found in [RFC7950].2.1. Abbreviations
BFD - Bidirectional Forwarding Detection [RFC5880]. RPC - Remote Procedure Call [RFC1831]. DSCP - Differentiated Services Code Point. VRF - Virtual Routing and Forwarding [RFC4382]. OWAMP - One-Way Active Measurement Protocol [RFC4656]. TWAMP - Two-Way Active Measurement Protocol [RFC5357]. AS - Autonomous System. LSP - Label Switched Path. TE - Traffic Engineering. MPLS - Multiprotocol Label Switching. NI - Network Instance.
PTP - Precision Time Protocol [IEEE.1588v2]. NTP - Network Time Protocol [RFC5905].2.2. Terminology
MAC - Media Access Control. MAC address - Address for the data-link layer interface. TP - Test Point. The TP is a functional entity that is defined at a node in the network and can initiate and/or react to OAM diagnostic tests. This document focuses on the data-plane functionality of TPs. RPC operation - A specific Remote Procedure Call. CC - A Continuity Check [RFC7276] is used to verify that a destination is reachable and therefore also referred to as reachability verification.2.3. Tree Diagrams
Tree diagrams used in this document follow the notation defined in [RFC8340].3. Overview of the Connectionless OAM Model
The YANG data model for OAM protocols that use connectionless communications has been split into two modules: o The "ietf-lime-time-types" module provides common definitions such as Time-related data types and Timestamp-related data types. o The "ietf-connectionless-oam" module defines technology- independent abstraction of key OAM constructs for OAM protocols that use connectionless communication. The "ietf-connectionless-oam" module augments the "/networks/network/ node" path defined in the "ietf-network" module [RFC8345] with the 'test-point-locations' grouping defined in Section 3.5. The network nodes in the "/networks/network/node" path are used to describe the network hierarchies and the inventory of nodes contained in a network. Under the 'test-point-locations' grouping, each test point location is chosen based on the 'tp-location-type' leaf, which, when chosen, leads to a container that includes a list of 'test-point-locations'.
Each 'test-point-locations' list includes a 'test-point-location- info' grouping. The 'test-point-location-info' grouping includes: o 'tp-technology' grouping, o 'tp-tools' grouping, and o 'connectionless-oam-tps' grouping. The groupings of 'tp-address' and 'tp-address-ni' are kept out of the 'test-point-location-info' grouping to make it addressing agnostic and allow varied composition. Depending upon the choice of the 'tp-location-type' (determined by the 'tp-address-ni'), each container differs in its composition of 'test-point-locations', while the 'test-point-location-info' is a common aspect of every 'test-point-locations'. The 'tp-address-ni' grouping is used to describe the corresponding network instance. The 'tp-technology' grouping indicates OAM technology details. The 'connectionless-oam-tps' grouping is used to describe the relationship of one test point with other test points. The 'tp-tools' grouping describes the OAM tools supported. In addition, at the top of the model, there is an 'cc-oper-data' container for session statistics. A grouping is also defined for common session statistics, and these are only applicable for proactive OAM sessions (see Section 3.2).3.1. TP Address
With connectionless OAM protocols, the TP address can be one of the following types: o MAC address [RFC6136] at the data-link layer for TPs o IPv4 or IPv6 address at the IP layer for TPs o TP-attribute identifying a TP associated with an application-layer function o Router-id to represent the device or node, which is commonly used to identify nodes in routing and other control-plane protocols [RFC8294]. To define a forwarding treatment of a test packet, the 'tp-address' grouping needs to be associated with additional parameters, e.g., DSCP for IP or Traffic Class [RFC5462] for MPLS. In the generic
connectionless OAM YANG data model, these parameters are not explicitly configured. The model user can add corresponding parameters according to their requirements.3.2. Tools
The different OAM tools may be used in one of two basic types of activation: proactive and on-demand. Proactive OAM refers to OAM actions that are carried out continuously to permit proactive reporting of faults. The proactive OAM method requires persistent configuration. On-demand OAM refers to OAM actions that are initiated via manual intervention for a limited time to carry out specific diagnostics. The on-demand OAM method requires only transient configuration (e.g., [RFC7276] and [G.8013]). In connectionless OAM, the 'session-type' grouping is defined to indicate which kind of activation will be used by the current session. In connectionless OAM, the tools attribute is used to describe a toolset for fault detection and isolation. In addition, it can serve as a constraint condition when the base model is extended to a specific OAM technology. For example, to fulfill the ICMP PING configuration, the "../coam:continuity-check" leaf should be set to "true", and then the LIME base model should be augmented with details specific to ICMP PING.3.3. OAM Neighboring Test Points
Given that typical network communication stacks have a multi-layer architecture, the set of associated OAM protocols has also a multi- layer structure; each communication layer in the stack may have its own OAM protocol [RFC7276] that may also be linked to a specific administrative domain. Management of these OAM protocols will necessitate associated test points in the nodes accessible by appropriate management domains. Accordingly, a given network interface may actually present several test points. Each OAM test point may have an associated list of neighboring test points that are in other layers up and down the protocol stack for the same interface and are therefore related to the current test point. This allows users to easily navigate between related neighboring layers to efficiently troubleshoot a defect. In this model, the 'position' leaf defines the relative position of the neighboring test point corresponding to the current test point, and it is provided to allow correlation of faults at different locations. If there is one neighboring test point placed before the current test point, the 'position' leaf is set to -1. If there is one neighboring
test point placed after the current test point, the 'position' leaf
is set to 1. If there is no neighboring test point placed before or
after the current test point, the 'position' leaf is set to 0.
+-- oam-neighboring-tps* [index]
+-- index? uint16
+-- position? int8
+-- (tp-location)?
+--:(mac-address)
| +-- mac-address-location? yang:mac-address
+--:(ipv4-address)
| +-- ipv4-address-location? inet:ipv4-address
+--:(ipv6-address)
| +-- ipv6-address-location? inet:ipv6-address
+--:(as-number)
| +-- as-number-location? inet:as-number
+--:(router-id)
+-- router-id-location? rt:router-id
3.4. Test Point Location Information
This is a generic grouping for Test Point Location Information (i.e.,
'test-point-location-info' grouping). It provides details of Test
Point Location using the 'tp-technology', 'tp-tools', and
'oam-neighboring-tps' groupings, all of which are defined above.
3.5. Test Point Locations
This is a generic grouping for Test Point Locations. 'tp-location-
type' leaf is used to define location types -- for example,
'ipv4-location-type', 'ipv6-location-type', etc. Container is
defined under each location type containing a list keyed to a test
point address, Test Point Location Information defined in the section
above, and network instance name (e.g., VRF instance name) if
required.
3.6. Path Discovery Data
This is a generic grouping for the path discovery data model that can
be retrieved by any data retrieval method, including RPC operations.
Path discovery data output from methods, includes 'src-test-point'
container, 'dst-test-point' container, 'sequence-number' leaf,
'hop-cnt' leaf, session statistics of various kinds, and information
related to path verification and path trace. Path discovery includes
data to be retrieved on a 'per-hop' basis via a list of 'path-trace-
info-list' items which includes information such as 'timestamp'
grouping, 'ingress-intf-name', 'egress-intf-name', and 'app-meta-
data'. The path discovery data model is made generic enough to allow
different methods of data retrieval. None of the fields are made mandatory for that reason. Note that a set of retrieval methods are defined in [RFC8533].3.7. Continuity Check Data
This is a generic grouping for the Continuity Check data model that can be retrieved by any data retrieval methods including RPC operations. Continuity Check data output from methods, includes 'src-test-point' container, 'dst-test-point' container, 'sequence-number' leaf, 'hop-cnt' leaf, and session statistics of various kinds. The Continuity Check data model is made generic enough to allow different methods of data retrieval. None of the fields are made mandatory for that reason. Noted that a set of retrieval methods are defined in [RFC8533].3.8. OAM Data Hierarchy
The complete data hierarchy related to the OAM YANG data model is presented below. module: ietf-connectionless-oam +--ro cc-session-statistics-data {continuity-check}? +--ro cc-session-statistics* [type] +--ro type identityref +--ro cc-ipv4-sessions-statistics | +--ro cc-session-statistics | +--ro session-count? uint32 | +--ro session-up-count? uint32 | +--ro session-down-count? uint32 | +--ro session-admin-down-count? uint32 +--ro cc-ipv6-sessions-statistics +--ro cc-session-statistics +--ro session-count? uint32 +--ro session-up-count? uint32 +--ro session-down-count? uint32 +--ro session-admin-down-count? uint32 augment /nd:networks/nd:network/nd:node: +--rw tp-location-type? identityref +--rw ipv4-location-type | +--rw test-point-ipv4-location-list | +--rw test-point-locations* [ipv4-location ni] | +--rw ipv4-location inet:ipv4-address | +--rw ni routing-instance-ref | +--rw (technology)? | | +--:(technology-null) | | +--rw tech-null? empty | +--rw tp-tools
| | +--rw continuity-check boolean
| | +--rw path-discovery boolean
| +--rw root? <anydata>
| +--rw oam-neighboring-tps* [index]
| +--rw index uint16
| +--rw position? int8
| +--rw (tp-location)?
| +--:(mac-address)
| | +--rw mac-address-location? yang:mac-address
| +--:(ipv4-address)
| | +--rw ipv4-address-location? inet:ipv4-address
| +--:(ipv6-address)
| | +--rw ipv6-address-location? inet:ipv6-address
| +--:(as-number)
| | +--rw as-number-location? inet:as-number
| +--:(router-id)
| +--rw router-id-location? rt:router-id
+--rw ipv6-location-type
| +--rw test-point-ipv6-location-list
| +--rw test-point-locations* [ipv6-location ni]
| +--rw ipv6-location inet:ipv6-address
| +--rw ni routing-instance-ref
| +--rw (technology)?
| | +--:(technology-null)
| | +--rw tech-null? empty
| +--rw tp-tools
| | +--rw continuity-check boolean
| | +--rw path-discovery boolean
| +--rw root? <anydata>
| +--rw oam-neighboring-tps* [index]
| +--rw index uint16
| +--rw position? int8
| +--rw (tp-location)?
| +--:(mac-address)
| | +--rw mac-address-location? yang:mac-address
| +--:(ipv4-address)
| | +--rw ipv4-address-location? inet:ipv4-address
| +--:(ipv6-address)
| | +--rw ipv6-address-location? inet:ipv6-address
| +--:(as-number)
| | +--rw as-number-location? inet:as-number
| +--:(router-id)
| +--rw router-id-location? rt:router-id
+--rw mac-location-type
| +--rw test-point-mac-address-location-list
| +--rw test-point-locations* [mac-address-location]
| +--rw mac-address-location yang:mac-address
| +--rw (technology)?
| | +--:(technology-null)
| | +--rw tech-null? empty
| +--rw tp-tools
| | +--rw continuity-check boolean
| | +--rw path-discovery boolean
| +--rw root? <anydata>
| +--rw oam-neighboring-tps* [index]
| +--rw index uint16
| +--rw position? int8
| +--rw (tp-location)?
| +--:(mac-address)
| | +--rw mac-address-location? yang:mac-address
| +--:(ipv4-address)
| | +--rw ipv4-address-location? inet:ipv4-address
| +--:(ipv6-address)
| | +--rw ipv6-address-location? inet:ipv6-address
| +--:(as-number)
| | +--rw as-number-location? inet:as-number
| +--:(router-id)
| +--rw router-id-location? rt:router-id
+--rw group-as-number-location-type
| +--rw test-point-as-number-location-list
| +--rw test-point-locations* [as-number-location]
| +--rw as-number-location inet:as-number
| +--rw ni? routing-instance-ref
| +--rw (technology)?
| | +--:(technology-null)
| | +--rw tech-null? empty
| +--rw tp-tools
| | +--rw continuity-check boolean
| | +--rw path-discovery boolean
| +--rw root? <anydata>
| +--rw oam-neighboring-tps* [index]
| +--rw index uint16
| +--rw position? int8
| +--rw (tp-location)?
| +--:(mac-address)
| | +--rw mac-address-location? yang:mac-address
| +--:(ipv4-address)
| | +--rw ipv4-address-location? inet:ipv4-address
| +--:(ipv6-address)
| | +--rw ipv6-address-location? inet:ipv6-address
| +--:(as-number)
| | +--rw as-number-location? inet:as-number
| +--:(router-id)
| +--rw router-id-location? rt:router-id
+--rw group-router-id-location-type
+--rw test-point-system-info-location-list
+--rw test-point-locations* [router-id-location]
+--rw router-id-location rt:router-id
+--rw ni? routing-instance-ref
+--rw (technology)?
| +--:(technology-null)
| +--rw tech-null? empty
+--rw tp-tools
| +--rw continuity-check boolean
| +--rw path-discovery boolean
+--rw root? <anydata>
+--rw oam-neighboring-tps* [index]
+--rw index uint16
+--rw position? int8
+--rw (tp-location)?
+--:(mac-address)
| +--rw mac-address-location? yang:mac-address
+--:(ipv4-address)
| +--rw ipv4-address-location? inet:ipv4-address
+--:(ipv6-address)
| +--rw ipv6-address-location? inet:ipv6-address
+--:(as-number)
| +--rw as-number-location? inet:as-number
+--:(router-id)
+--rw router-id-location? rt:router-id
4. LIME Time Types YANG Module
<CODE BEGINS> file "ietf-lime-time-types@2019-04-16.yang"
module ietf-lime-time-types {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-lime-time-types";
prefix lime;
organization
"IETF LIME Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/lime>
WG List: <mailto:lmap@ietf.org>
Editor: Qin Wu
<bill.wu@huawei.com>";
description
"This module provides time-related definitions used by the data
models written for Layer Independent OAM Management in the
Multi-Layer Environment (LIME). This module defines
identities but no schema tree elements.
Copyright (c) 2019 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 8532; see
the RFC itself for full legal notices.";
revision 2019-04-16 {
description
"Initial version.";
reference
"RFC 8532: Generic YANG Data Model for the Management of
Operations, Administration, and Maintenance (OAM) Protocols
That Use Connectionless Communications";
}
/*** Collection of common types related to time ***/
/*** Time unit identity ***/
identity time-unit-type {
description
"Time unit type.";
}
identity hours {
base time-unit-type;
description
"Time unit in hours.";
}
identity minutes {
base time-unit-type;
description
"Time unit in minutes.";
}
identity seconds {
base time-unit-type;
description
"Time unit in seconds.";
}
identity milliseconds {
base time-unit-type;
description
"Time unit in milliseconds.";
}
identity microseconds {
base time-unit-type;
description
"Time unit in microseconds.";
}
identity nanoseconds {
base time-unit-type;
description
"Time unit in nanoseconds.";
}
/*** Timestamp format Identity ***/
identity timestamp-type {
description
"Base identity for Timestamp Type.";
}
identity truncated-ptp {
base timestamp-type;
description
"Identity for 64-bit short-format PTP timestamp.";
}
identity truncated-ntp {
base timestamp-type;
description
"Identity for 32-bit short-format NTP timestamp.";
}
identity ntp64 {
base timestamp-type;
description
"Identity for 64-bit NTP timestamp.";
}
identity icmp {
base timestamp-type;
description
"Identity for 32-bit ICMP timestamp.";
}
identity ptp80 {
base timestamp-type;
description
"Identity for 80-bit PTP timestamp.";
}
}
<CODE ENDS>
(page 15 continued on part 2)
