Generic YANG Data Model for Connection Oriented Operations, Administration, and Maintenance(OAM) protocols

Generic YANG Data Model for Connection Oriented Operations, Administration, and Maintenance(OAM) protocols CISCO Systems

510 McCarthy Blvd Milpitas CA 95035 USA dekumar@cisco.com

Huawei

101 Software Avenue, Yuhua District Nanjing Jiangsu 210012 China bill.wu@huawei.com

Huawei Technologies,Co.,Ltd

101 Software Avenue, Yuhua District Nanjing 210012 China wangzitao@huawei.com

OPS Area This document presents a base YANG Data model for connection-oriented Operations, Administration, and Maintenance(OAM) protocols. It provides a technology-independent abstraction of key OAM constructs for such protocols. The model presented here can be extended to include technology specific details. This guarantees uniformity in the management of OAM protocols and provides support for nested OAM workflows (i.e., performing OAM functions at different levels through a unified interface). The YANG model in this document conforms to the Network Management Datastore Architecture.

Operations, Administration, and Maintenance (OAM) are important networking functions that allow operators to: Monitor network connections (Connectivity Verification, Continuity Check). Troubleshoot failures (Fault verification and localization). Monitor Performance An overview of OAM tools is presented in . Over the years, many technologies have developed similar tools for fault and performance management. The different sets of OAM tools may support both connection-oriented technologies 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 end points without prior arrangement, but control information is required to identify the destination (e.g., ). The YANG Data model for OAM protocols using connectionless communications is specified in . Connectivity Fault Management is a well-established OAM standard that is widely adopted for Ethernet networks. ITU-T , MEF Service OAM , MPLS-TP and TRILL all define OAM mechanisms based on the manageability frame work of CFM . Given the wide adoption of the underlying OAM concepts defined in CFM , it is a reasonable choice to develop the unified management framework for connection-oriented OAM based on those concepts. In this document, we take the CFM model and extend it to a technology independent framework and define the corresponding YANG model accordingly. The YANG model presented in this document is the base model for connection-oriented OAM protocols and supports generic continuity check, connectivity verification and path discovery (traceroute). The generic YANG model for connection-oriented OAM is designed to be extensible to other connection-oriented technologies. Technology dependent nodes and remote process call (RPC) commands are defined in technology specific YANG models, which use and extend the base model defined here. As an example, VXLAN uses source UDP port number for flow entropy, while TRILL uses either MAC addresses, the VLAN tag or fine grain label, and/or IP addresses for flow entropy in the hashing for multipath selection. To capture this variation, corresponding YANG models would define the applicable structures as augmentation to the generic base model presented here. This accomplishes three goals: First it keeps each YANG model smaller and more manageable. Second, it allows independent development of corresponding YANG models. Third, implementations can limit support to only the applicable set of YANG models. (e.g. TRILL RBridge may only need to implement Generic model and the TRILL YANG model). The YANG data model presented in this document is generated at the management layer. Encapsulations and state machines may differ according to each OAM protocol. A user who wishes to issues a Continuity Check command or a Loopback or initiate a performance monitoring session can do so in the same manner regardless of the underlying protocol or technology or specific vendor implementation. As an example, consider a scenario where connectivity from device A loopback to device B fails. Between device A and B there are IEEE 802.1 bridges a, b and c. Let's assume a,b and c are using CFM . A user upon detecting the loopback failure, may decide to drill down to the lower level at different segments of the path and issue the corresponding fault verification (LBM) and fault isolation (LTM) tools, using the same API. This ability to drill down to a lower layer of the protocol stack at a specific segment within a path for fault localization and troubleshooting is referred to as "nested OAM workflow". It is a useful concept that leads to efficient network troubleshooting and maintenance workflows. The connection-oriented OAM YANG model presented in this document facilitates that without needing changes to the underlying protocols. The YANG model in this document conforms to the Network Management Datastore Architecture defined in .

The keywords "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 BCP14, , when, and only when, they appear in all capitals, as shown here. Many of the terms used in this document (including those set out in Section 2.1 and Section 2.2) are specific to the world of OAM. This document does not attempt to explain the terms, but does assume that the reader is familiar with the concepts. For a good overview, read [IEEE802.1Q]. For an example of how these OAM terms appear in IETF work, see [RFC6371].

- Continuity Check Message . - Equal Cost Multipath. - Loopback Message . - Linktrace Message . - Maintenance Point . - Maintenance End Point (Maintenance association End Point , MEG End Points ). - Maintenance Intermediate Point (Maintenance domain Intermediate Point , MEG Intermediate Point ). - Maintenance Association . - Maintenance Domain - Maintenance Entity Group - Multi-destination Tree Verification Message. - Operations, Administration, and Maintenance . - Transparent Interconnection of Lots of Links . - Connectivity Fault Management . - Remote Process Call. - Continuity Check . - Connectivity Verification .

- Continuity Checks are used to verify that a destination is reachable and therefore also referred to as reachability verification. - Connectivity Verification is used to verify that a destination is connected. It is also referred to as path verification and used to verify not only that the two MPs are connected, but also that they are connected through the expected path, allowing detection of unexpected topology changes. - The proactive OAM refers to OAM actions which are carried out continuously to permit proactive reporting of fault. Proactive OAM method requires persistent configuration. - The on-demand OAM refers to OAM actions which are initiated via manual intervention for a limited time to carry out diagnostics. The on-demand OAM method requires only transient configuration.

Tree diagrams used in this document follow the notation defined in .

In this document we define a generic YANG model for connection-oriented OAM protocols. The YANG model defined here is generic in a sense that other technologies can extend it for technology-specific needs. The Generic YANG model for connection-oriented OAM acts as the root for other OAM YANG models. This allows users to traverse between different OAM protocols with ease through a uniform API set. This also enables a nested OAM workflow. Figure 1 depicts the relationship of different OAM YANG models to the Generic YANG Model for connection-oriented OAM. The Generic YANG model for connection-oriented OAM provides a framework where technology-specific YANG models can inherit constructs from the base YANG models without needing to redefine them within the sub-technology.

+----------+ |Connection| | Oriented | | gen | |OAM YANG | +-+-+-+-+-++ | | | +------------------------------------------+ | | | +-+-+-+-+-+ +-+-+-+-+-+ +-+-+-+-+-+ | TRILL | | MPLS-TP | . . .| foo | |OAM YANG | |OAM YANG | |OAM YANG | +-+-+-+-+-+ +-+-+-+-+-+ +-+-+-+-+-+ | | | | | +-+-+-+-+-+ | | . . .| foo | | | |sub tech | | | +-+-+-+-+-+ | | | | | | +-------------------------------------------------------+ | Uniform API | +-------------------------------------------------------+

In this document we adopt the concepts of the CFM model and structure it such that it can be adapted to different connection-oriented OAM protocols. At the top of the Model is the Maintenance Domain. Each Maintenance Domain is associated with a Maintenance Name and a Domain Level. Under each Maintenance Domain there is one or more Maintenance Associations (MA). In TRILL, the MA can correspond to Fine-Grained Label. Under each MA, there can be two or more MEPs (Maintenance End Points). MEPs are addressed by their respective technology specific address identifiers. The YANG model presented here provides flexibility to accommodate different addressing schemes. In the management protocol direction orthogonal to the Maintenance Domain, presented are the commands. Those, in YANG terms, are the RPC commands. These RPC commands provide uniform APIs for continuity check, connectivity verification, path discovery(traceroute) and their equivalents as well as other OAM commands. The OAM entities in the generic YANG model defined here will be either explicitly or implicitly configured using any of the OAM tools. The OAM tools used here are limited to the OAM toolset specified in section 5.1 of . In order to facilitate zero-touch experience, this document defines a default mode of OAM. The default mode of OAM is referred to as the Base Mode and specifies default values for each of model parameters, such as Maintenance Domain Level, Name of the Maintenance Association, Addresses of MEPs and so on. The default values of these depend on the technology. Base Mode for TRILL is defined in . Base mode for other technologies and future extensions developed in IETF will be defined in their corresponding documents. It is important to note that, no specific enhancements are needed in the YANG model to support Base Mode. Implementations that comply with this document, by default implement the data nodes of the applicable technology. Data nodes of the Base Mode are read-only nodes.

The container "domains" is the top level container within the gen-oam module. Within the container "domains", a separate list is maintained per MD. The MD list uses the key "md-name-string" for indexing. The "md-name-string" is a leaf and derived from type string. Additional name formats as defined in or other standards can be included by association of the "md-name-format" with an identity-ref. The "md-name-format" indicates the format of the augmented "md-name". The "md-name" is presented as choice/case construct. Thus, it is easily augmentable by derivative work.

Within a given Maintenance Domain there can be one or more Maintenance Associations (MA(s)). MAs are represented as a list and indexed by the "ma-name-string". Similar to "md-name" defined previously, additional name formats can be added by augmenting the name-format identity-ref and adding applicable case statements to "ma-name".

module: ietf-connection-oriented-oam +--rw domains +--rw domain* [technology md-name-string] . . +--rw mas +--rw ma* [ma-name-string] +--rw ma-name-string ma-name-string +--rw ma-name-format? identityref +--rw (ma-name)? | +--:(ma-name-null) | +--rw ma-name-null? empty

Within a given Maintenance Association (MA), there can be one or more Maintenance End Points (MEP). MEPs are represented as a list within the data hierarchy and indexed by the key "mep-name".

The RPC model facilitates issuing commands to a "server" (in this case to the device that need to execute the OAM command) and obtaining a response. RPC model defined here abstracts OAM specific commands in a technology independent manner. There are several RPC commands defined for the purpose of OAM. In this section we present a snippet of the continuity check command for illustration purposes. Please refer to Section 4.5 for the complete data hierarchy and Section 5 for the YANG model.

module: ietf-connection-oriented-oam +--rw domains +--rw domain* [technology md-name-string] +--rw technology identityref . . rpcs: +---x continuity-check {continuity-check}? | +---w input | | +---w technology? identityref | | +---w md-name-string -> /domains/domain/md-name-string | | +---w md-level? -> /domains/domain/md-level | | +---w ma-name-string -> /domains/domain/mas/ma/ma-name-string | | +---w cos-id? uint8 | | +---w ttl? uint8 | | +---w sub-type? identityref | | +---w source-mep? -> /domains/domain/mas/ma/mep/mep-name | | +---w destination-mep | | | +---w (mep-address)? | | | | +--:(mac-address) | | | | | +---w mac-address? yang:mac-address | | | | +--:(ip-address) | | | | +---w ip-address? inet:ip-address | | | +---w (mep-id)? | | | | +--:(mep-id-int) | | | | +---w mep-id-int? int32 | | | +---w mep-id-format? identityref | | +---w count? uint32 | | +---w cc-transmit-interval? time-interval | | +---w packet-size? uint32 | +--ro output | +--ro (monitor-stats)? | +--:(monitor-null) | +--ro monitor-null? empty +---x continuity-verification {connectivity-verification}? | +---w input | | +---w md-name-string -> /domains/domain/md-name-string | | +---w md-level? -> /domains/domain/md-level | | +---w ma-name-string -> /domains/domain/mas/ma/ma-name-string | | +---w cos-id? uint8 | | +---w ttl? uint8 | | +---w sub-type? identityref | | +---w source-mep? -> /domains/domain/mas/ma/mep/mep-name | | +---w destination-mep | | | +---w (mep-address)? | | | | +--:(mac-address) | | | | | +---w mac-address? yang:mac-address | | | | +--:(ip-address) | | | | +---w ip-address? inet:ip-address | | | +---w (mep-id)? | | | | +--:(mep-id-int) | | | | +---w mep-id-int? int32 | | | +---w mep-id-format? identityref | | +---w count? uint32 | | +---w interval? time-interval | | +---w packet-size? uint32 | +--ro output | +--ro (monitor-stats)? | +--:(monitor-null) | +--ro monitor-null? empty +---x traceroute {traceroute}? +---w input | +---w md-name-string -> /domains/domain/md-name-string | +---w md-level? -> /domains/domain/md-level | +---w ma-name-string -> /domains/domain/mas/ma/ma-name-string | +---w cos-id? uint8 | +---w ttl? uint8 | +---w command-sub-type? identityref | +---w source-mep? -> /domains/domain/mas/ma/mep/mep-name | +---w destination-mep | | +---w (mep-address)? | | | +--:(mac-address) | | | | +---w mac-address? yang:mac-address | | | +--:(ip-address) | | | +---w ip-address? inet:ip-address | | +---w (mep-id)? | | | +--:(mep-id-int) | | | +---w mep-id-int? int32 | | +---w mep-id-format? identityref | +---w count? uint32 | +---w interval? time-interval +--ro output +--ro response* [response-index] +--ro response-index uint8 +--ro ttl? uint8 +--ro destination-mep | +--ro (mep-address)? | | +--:(mac-address) | | | +--ro mac-address? yang:mac-address | | +--:(ip-address) | | +--ro ip-address? inet:ip-address | +--ro (mep-id)? | | +--:(mep-id-int) | | +--ro mep-id-int? int32 | +--ro mep-id-format? identityref +--ro mip {mip}? | +--ro interface? if:interface-ref | +--ro (mip-address)? | +--:(mac-address) | | +--ro mac-address? yang:mac-address | +--:(ip-address) | +--ro ip-address? inet:ip-address +--ro (monitor-stats)? +--:(monitor-null) +--ro monitor-null? empty

Notification is sent on detecting defect condition and on clearing defect with Maintenance Domain Name, MA Name, defect-type (The currently active defects), generating-mepid, and defect-message to indicate more details.

Grouping for monitoring statistics is to be used by technology specific YANG modules which Augment Generic YANG Model to provide statistics due to pro-active OAM like CCM Messages. For example CCM Transmit, CCM Receive, CCM Errors, etc.

The complete data hierarchy related to the connection-oriented OAM YANG model is presented below.

module: ietf-connection-oriented-oam +--rw domains +--rw domain* [technology md-name-string] +--rw technology identityref +--rw md-name-string md-name-string +--rw md-name-format? identityref +--rw (md-name)? | +--:(md-name-null) | +--rw md-name-null? empty +--rw md-level? md-level +--rw mas +--rw ma* [ma-name-string] +--rw ma-name-string ma-name-string +--rw ma-name-format? identityref +--rw (ma-name)? | +--:(ma-name-null) | +--rw ma-name-null? empty +--rw (connectivity-context)? | +--:(context-null) | +--rw context-null? empty +--rw cos-id? uint8 +--rw cc-enable? boolean +--rw mep* [mep-name] | +--rw mep-name mep-name | +--rw (mep-id)? | | +--:(mep-id-int) | | +--rw mep-id-int? int32 | +--rw mep-id-format? identityref | +--rw (mep-address)? | | +--:(mac-address) | | | +--rw mac-address? yang:mac-address | | +--:(ip-address) | | +--rw ip-address? inet:ip-address | +--rw cos-id? uint8 | +--rw cc-enable? boolean | +--rw session* [session-cookie] | +--rw session-cookie uint32 | +--rw destination-mep | | +--rw (mep-id)? | | | +--:(mep-id-int) | | | +--rw mep-id-int? int32 | | +--rw mep-id-format? identityref | +--rw destination-mep-address | | +--rw (mep-address)? | | +--:(mac-address) | | | +--rw mac-address? yang:mac-address | | +--:(ip-address) | | +--rw ip-address? inet:ip-address | +--rw cos-id? uint8 +--rw mip* [name] {mip}? +--rw name string +--rw interface? if:interface-ref +--rw (mip-address)? +--:(mac-address) | +--rw mac-address? yang:mac-address +--:(ip-address) +--rw ip-address? inet:ip-address rpcs: +---x continuity-check {continuity-check}? | +---w input | | +---w technology? identityref | | +---w md-name-string -> /domains/domain/md-name-string | | +---w md-level? -> /domains/domain/md-level | | +---w ma-name-string -> /domains/domain/mas/ma/ma-name-string | | +---w cos-id? uint8 | | +---w ttl? uint8 | | +---w sub-type? identityref | | +---w source-mep? -> /domains/domain/mas/ma/mep/mep-name | | +---w destination-mep | | | +---w (mep-address)? | | | | +--:(mac-address) | | | | | +---w mac-address? yang:mac-address | | | | +--:(ip-address) | | | | +---w ip-address? inet:ip-address | | | +---w (mep-id)? | | | | +--:(mep-id-int) | | | | +---w mep-id-int? int32 | | | +---w mep-id-format? identityref | | +---w count? uint32 | | +---w cc-transmit-interval? time-interval | | +---w packet-size? uint32 | +--ro output | +--ro (monitor-stats)? | +--:(monitor-null) | +--ro monitor-null? empty +---x continuity-verification {connectivity-verification}? | +---w input | | +---w md-name-string -> /domains/domain/md-name-string | | +---w md-level? -> /domains/domain/md-level | | +---w ma-name-string -> /domains/domain/mas/ma/ma-name-string | | +---w cos-id? uint8 | | +---w ttl? uint8 | | +---w sub-type? identityref | | +---w source-mep? -> /domains/domain/mas/ma/mep/mep-name | | +---w destination-mep | | | +---w (mep-address)? | | | | +--:(mac-address) | | | | | +---w mac-address? yang:mac-address | | | | +--:(ip-address) | | | | +---w ip-address? inet:ip-address | | | +---w (mep-id)? | | | | +--:(mep-id-int) | | | | +---w mep-id-int? int32 | | | +---w mep-id-format? identityref | | +---w count? uint32 | | +---w interval? time-interval | | +---w packet-size? uint32 | +--ro output | +--ro (monitor-stats)? | +--:(monitor-null) | +--ro monitor-null? empty +---x traceroute {traceroute}? +---w input | +---w md-name-string -> /domains/domain/md-name-string | +---w md-level? -> /domains/domain/md-level | +---w ma-name-string -> /domains/domain/mas/ma/ma-name-string | +---w cos-id? uint8 | +---w ttl? uint8 | +---w command-sub-type? identityref | +---w source-mep? -> /domains/domain/mas/ma/mep/mep-name | +---w destination-mep | | +---w (mep-address)? | | | +--:(mac-address) | | | | +---w mac-address? yang:mac-address | | | +--:(ip-address) | | | +---w ip-address? inet:ip-address | | +---w (mep-id)? | | | +--:(mep-id-int) | | | +---w mep-id-int? int32 | | +---w mep-id-format? identityref | +---w count? uint32 | +---w interval? time-interval +--ro output +--ro response* [response-index] +--ro response-index uint8 +--ro ttl? uint8 +--ro destination-mep | +--ro (mep-address)? | | +--:(mac-address) | | | +--ro mac-address? yang:mac-address | | +--:(ip-address) | | +--ro ip-address? inet:ip-address | +--ro (mep-id)? | | +--:(mep-id-int) | | +--ro mep-id-int? int32 | +--ro mep-id-format? identityref +--ro mip {mip}? | +--ro interface? if:interface-ref | +--ro (mip-address)? | +--:(mac-address) | | +--ro mac-address? yang:mac-address | +--:(ip-address) | +--ro ip-address? inet:ip-address +--ro (monitor-stats)? +--:(monitor-null) +--ro monitor-null? empty notifications: +---n defect-condition-notification | +--ro technology? identityref | +--ro md-name-string -> /domains/domain/md-name-string | +--ro ma-name-string -> /domains/domain/mas/ma/ma-name-string | +--ro mep-name? -> /domains/domain/mas/ma/mep/mep-name | +--ro defect-type? identityref | +--ro generating-mepid | | +--ro (mep-id)? | | | +--:(mep-id-int) | | | +--ro mep-id-int? int32 | | +--ro mep-id-format? identityref | +--ro (defect)? | +--:(defect-null) | | +--ro defect-null? empty | +--:(defect-code) | +--ro defect-code? int32 +---n defect-cleared-notification +--ro technology? identityref +--ro md-name-string -> /domains/domain/md-name-string +--ro ma-name-string -> /domains/domain/mas/ma/ma-name-string +--ro mep-name? -> /domains/domain/mas/ma/mep/mep-name +--ro defect-type? identityref +--ro generating-mepid | +--ro (mep-id)? | | +--:(mep-id-int) | | +--ro mep-id-int? int32 | +--ro mep-id-format? identityref +--ro (defect)? +--:(defect-null) | +--ro defect-null? empty +--:(defect-code) +--ro defect-code? int32

This module imports typedefs from [RFC6991] and [I-D.ietf-netmod-rfc7223bis], and it references [RFC6371],[RFC6905], [RFC7276]. RFC Ed.: update the date below with the date of RFC publication and remove this note. <CODE BEGINS> file "ietf-connection-oriented-oam@2018-02-07.yang"

module ietf-connection-oriented-oam { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-connection-oriented-oam"; prefix co-oam; import ietf-yang-types { prefix yang; } import ietf-inet-types { prefix inet; } import ietf-interfaces { prefix if; } organization "IETF LIME Working Group"; contact "WG Web: http://tools.ietf.org/wg/lime WG List: mailto:lime@ietf.org Editor: Deepak Kumar dekumar@cisco.com Editor: Qin Wu bill.wu@huawei.com Editor: Zitao Wang wangzitao@huawei.com"; description "This YANG module defines the generic configuration, statistics and rpc for connection oriented OAM to be used within IETF in a protocol independent manner. Functional level abstraction is independent with YANG modeling. It is assumed that each protocol maps corresponding abstracts to its native format. Each protocol may extend the YANG model defined here to include protocol specific extensions Copyright (c) 2018 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 the RFC itself for full legal notices."; revision 2018-02-07 { description "Initial revision."; reference "RFC xxxx: Generic YANG Data Model for Connection Oriented OAM protocols"; } feature connectivity-verification { description "This feature indicates that the server supports executing connectivity verification OAM command and returning a response. Servers that do not advertise this feature will not support executing connectivity verification command or rpc model for connectivity verification command."; } feature continuity-check { description "This feature indicates that the server supports executing continuity check OAM command and returning a response. Servers that do not advertise this feature will not support executing continuity check command or rpc model for continuity check command."; } feature traceroute { description "This feature indicates that the server supports executing traceroute OAM command and returning a response. Servers that do not advertise this feature will not support executing traceroute command or rpc model for traceroute command."; } feature mip { description "This feature indicates that the Maintenance Intermediate Point(MIP) needs to be explicit configured"; } identity technology-types { description "This is the base identity of technology types which are TRILL, MPLS-TP, etc"; } identity command-sub-type { description "Defines different rpc command subtypes, e.g rfc6905 trill OAM, this is optional for most cases"; reference "RFC 6905: Requirements for OAM in Transparent Interconnection of Lots of Links (TRILL)"; } identity on-demand { base command-sub-type; description "On demand activation - indicates that the tool is activated manually to detect a specific anomaly. On-demand OAM method requires only transient configuration."; reference "RFC 7276: An Overview of Operations, Administration, and Maintenance (OAM) Tools"; } identity proactive { base command-sub-type; description "Proactive activation - indicates that the tool is activated on a continual basis, where messages are sent periodically, and errors are detected when a certain number of expected messages are not received. Proactive OAM method requires persistent configuration."; reference "RFC 7276: An Overview of Operations, Administration, and Maintenance (OAM) Tools"; } identity name-format { description "This defines the name format, IEEE 8021ag CFM defines varying styles of names. It is expected name format as an identity ref to be extended with new types."; } identity name-format-null { base name-format; description "Defines name format as null"; } identity identifier-format { description "Identifier-format identity can be augmented to define other format identifiers used in MEP-ID etc"; } identity identifier-format-integer { base identifier-format; description "Defines identifier-format to be integer"; } identity defect-types { description "Defines different defect types, e.g. Remote Defect Indication (rdi), loss of continuity"; } identity rdi { base defect-types; description "The Remote Defect Indication (rdi) indicates the aggregate health of the remote Maintenance End Points (MEPs)."; } identity remote-mep-defect { base defect-types; description "Indicates that one or more of the remote Maintenance End Points(MEPs)is reporting a failure "; } identity loss-of-continuity { base defect-types; description "Indicate there is no proactive Continuity Check (CC) OAM packets from the source Maintenance End Point (MEP) (and in the case of Connectivity Verification , this includes the requirement to have the expected unique, technology dependent source MEP identifier) received within the interval."; reference "RFC 6371: Operations, Administration, and Maintenance Framework for MPLS-Based Transport Networks"; } identity cv-defect { base defect-types; description "This function should support monitoring between the Maintenance End Points (MEPs) and, in addition, between a MEP and Maintenance Intermediate Point (MIP). When performing Connectivity Verification, the need for the Continuity Check and Connectivity Verification (CC-V) messages to include unique identification of the MEG that is being monitored and the MEP that originated the message."; reference "RFC 6371: Operations, Administration, and Maintenance Framework for MPLS-Based Transport Networks"; } identity invalid-oam-defect { base defect-types; description "Indicates that one or more invalid OAM messages has been received and that 3.5 times that OAM message transmission interval has not yet expired."; } identity cross-connect-defect { base defect-types; description "Indicates that one or more cross-connect defect (for example, a service ID does not match the VLAN.) messages has been received and that 3.5 times that OAM message transmission interval has not yet expired."; } typedef mep-name { type string; description "Generic administrative name for a Maintenance End Point (MEP)."; } typedef time-interval { type decimal64 { fraction-digits 2; } units "milliseconds"; description "Time interval between packets in milliseconds. Time interval should not be less than 0. 0 means no packets are sent."; } typedef md-name-string { type string; description "Generic administrative name for Maintenance Domain (MD)."; } typedef ma-name-string { type string; description "Generic administrative name for a Maintenance Association (MA)."; } typedef oam-counter32 { type yang:zero-based-counter32; description "Define 32 bit counter for OAM."; } typedef md-level { type uint32 { range "0..255"; } description "Maintenance Domain level. The level may be restricted in certain protocols (e.g., protocol in layer 0 to layer 7)."; } grouping maintenance-domain-reference { description "This grouping uniquely identifies a maintenance domain."; leaf maintenance-domain { type leafref { path "/co-oam:domains/co-oam:domain/co-oam:md-name-string"; } description "A reference to a specific Maintenance Domain."; } } grouping maintenance-association-reference { description "This grouping uniquely identifies a maintenance association. It consists of a maintence-domain-reference and a maintenance-association leafref"; uses maintenance-domain-reference; leaf maintenance-association { type leafref { path "/co-oam:domains/co-oam:domain[co-oam:md-name-string " +"= current()/../maintenance-domain]/co-oam:mas" +"/co-oam:ma/co-oam:ma-name-string"; } description "A reference to a specific Maintenance Association."; } } grouping maintenance-association-end-point-reference { description "This grouping uniquely identifies a maintenance association. It consists of a maintence-association-reference and a maintenance-association-end-point leafref"; uses maintenance-association-reference; leaf maintenance-association-end-point { type leafref { path "/co-oam:domains/co-oam:domain[co-oam:md-name-string " +"= current()/../maintenance-domain]/co-oam:mas" +"/co-oam:ma[co-oam:ma-name-string = " +"current()/../maintenance-association]" +"/co-oam:mep/co-oam:mep-name"; } description "A reference to a specific Maintenance association End Point."; } } grouping time-to-live { leaf ttl { type uint8; description "Time to Live."; } description "Time to Live grouping."; } grouping defect-message { choice defect { case defect-null { description "This is a placeholder when no defect status is needed"; leaf defect-null { type empty; description "There is no defect to be defined, it will be defined in technology specific model."; } } case defect-code { description "This is a placeholder to display defect code."; leaf defect-code { type int32; description "Defect code is integer value specific to a technology."; } } description "Defect Message choices."; } description "Defect Message."; } grouping mep-address { choice mep-address { default ip-address; case mac-address { leaf mac-address { type yang:mac-address; description "MAC Address."; } description "MAC Address based Maintenance End Point (MEP) Addressing."; } case ip-address { leaf ip-address { type inet:ip-address; description "IP Address."; } description "IP Address based Maintenance End Point(MEP) Addressing."; } description "Maintenance End Point (MEP) Addressing."; } description "Grouping for Maintenance End Point(MEP) Address"; } grouping mip-address { choice mip-address { default ip-address; case mac-address { leaf mac-address { type yang:mac-address; description "MAC Address of Maintenance Intermediate Point"; } description "MAC Address based Maintenance Intermediate Point (MIP) Addressing."; } case ip-address { leaf ip-address { type inet:ip-address; description "IP Address."; } description "IP Address based Maintenance Intermediate Point(MIP) Addressing."; } description "Maintenance Intermediate Point (MIP) Addressing."; } description "Maintenance Intermediate Point (MIP) Address."; } grouping maintenance-domain-id { description "Grouping containing leaves sufficient to identify a Maintenance Domain."; leaf technology { type identityref { base technology-types; } mandatory true; description "Defines the technology."; } leaf md-name-string { type md-name-string; mandatory true; description "Defines the generic administrative maintenance domain name."; } } grouping md-name { leaf md-name-format { type identityref { base name-format; } description "Maintenance Domain Name format."; } choice md-name { case md-name-null { leaf md-name-null { when "derived-from-or-self(../md-name-format," +"'name-format-null')" { description "Maintenance Domain (MD) name format is equal to null format."; } type empty; description "Maintenance Domain (MD) name Null."; } } description "Maintenance Domain (MD) name."; } description "Maintenance Domain (MD) name."; } grouping ma-identifier { description "Grouping containing leaves sufficient to identify an Maintenance Association (MA)."; leaf ma-name-string { type ma-name-string; description "Maintenance Association (MA) name string."; } } grouping ma-name { description "Maintenance Association (MA) name."; leaf ma-name-format { type identityref { base name-format; } description "Maintenance Association (MA) name format."; } choice ma-name { case ma-name-null { leaf ma-name-null { when "derived-from-or-self(../ma-name-format, " +"'name-format-null')" { description "Maintenance Association (MA)."; } type empty; description "Empty"; } } description "Maintenance Association) name(MA)."; } } grouping mep-id { choice mep-id { default "mep-id-int"; case mep-id-int { leaf mep-id-int { type int32; description "Maintenance End Point (MEP) ID in integer format."; } } description "Maintenance End Point (MEP) ID."; } leaf mep-id-format { type identityref { base identifier-format; } description "Maintenance End Point (MEP) ID format."; } description "Maintenance End Point (MEP) ID."; } grouping mep { description "Defines elements within the Maintenance End Point (MEP)."; leaf mep-name { type mep-name; mandatory true; description "Generic administrative name of the Maintenance End Point (MEP)."; } uses mep-id; uses mep-address; } grouping monitor-stats { description "grouping for monitoring statistics, this will be augmented by others who use this component"; choice monitor-stats { default "monitor-null"; case monitor-null { description "This is a place holder when no monitoring statistics is needed"; leaf monitor-null { type empty; description "There is no monitoring statistics to be defined."; } } description "Define the monitor stats."; } } grouping connectivity-context { description "Grouping defining the connectivity context for an Maintenance Association (MA), for example, an LSP for MPLS-TP. This will be augmented by each protocol who use this component."; choice connectivity-context { default "context-null"; case context-null { description "This is a place holder when no context is needed."; leaf context-null { type empty; description "There is no context to be defined."; } } description "Connectivity context."; } } grouping cos { description "Grouping for Priority used in transmitted packets, for example, in the CoS field in MPLS-TP."; leaf cos-id { type uint8; description "Class of Service(CoS) id, this value is used to indicate Class of Service information ."; } } grouping mip-grouping { uses mip-address; description "Grouping for Maintenance Intermediate Point(MIP) configuration."; } container domains { description "Contains configuration related data. Within the container there is a list of fault domains. each domian has a List of Maintenance Association (MA)."; list domain { key "technology md-name-string"; description "Define a list of Domains within the ietf-connection-oriented-oam module."; uses maintenance-domain-id; uses md-name; leaf md-level { type md-level; description "Define the MD-Level."; } container mas { description "This container defines Maintenance Association (MA), within that have multiple MA and within MA have Maintenance End Point (MEP)."; list ma { key "ma-name-string"; uses ma-identifier; uses ma-name; uses connectivity-context; uses cos { description "Default class of service for this Maintenance Association (MA), which may be overridden for particular Maintenance End Points (MEPs), sessions or operations."; } leaf cc-enable { type boolean; description "Indicate whether the Continuity Check (CC) is enabled."; } list mep { key "mep-name"; description "Contain a list of Maintenance End Points (MEPs)"; uses mep; uses cos; leaf cc-enable { type boolean; description "Indicate whether the Continuity Check (CC)is enabled."; } list session { key "session-cookie"; description "Monitoring session to/from a particular remote Maintenance End Point (MEP). Depending on the protocol, this could represent Continuity Check (CC) messages received from a single remote MEP (if the protocol uses multicast CCs) or a target to which unicast echo request CCs are sent and from which responses are received (if the protocol uses a unicast request/response mechanism)."; leaf session-cookie { type uint32; description "Cookie to identify different sessions, when there are multiple remote Maintenance End Point(MEP) or multiple sessions tothe same remote MEP."; } container destination-mep { uses mep-id; description "Destination Maintenance End Point(MEP)."; } container destination-mep-address { uses mep-address; description "Destination Maintenance End Point (MEP) Address."; } uses cos; } } list mip { if-feature "mip"; key "name"; leaf name { type string; description "Identifier of Maintenance intermediate point"; } leaf interface { type if:interface-ref; description "Interface"; } uses mip-grouping; description "List for Maintenance Intermediate Point (MIP)."; } description "Maintenance Association list."; } } } } notification defect-condition-notification { description "Upon the defect condition is met, this notification is sent"; leaf technology { type identityref { base technology-types; } description "The technology"; } leaf md-name-string { type leafref { path "/domains/domain/md-name-string"; } mandatory true; description "Indicate which Maintenance Domain(MD) does the defect belong to."; } leaf ma-name-string { type leafref { path "/domains/domain/mas/ma/ma-name-string"; } mandatory true; description "Indicate which Maintenance Association (MA) is the defect associated with."; } leaf mep-name { type leafref { path "/domains/domain/mas/ma/mep/mep-name"; } description "Indicate which Maintenance End Point(MEP) is seeing the defect."; } leaf defect-type { type identityref { base defect-types; } description "The currently active defects on the specific Maintenance End Point (MEP)."; } container generating-mepid { uses mep-id; description "Indicate who is generating the defect (if known). If unknown set it as 0."; } uses defect-message { description "The defect message to indicate more details."; } } notification defect-cleared-notification { description "Upon defect cleared is met, this notification is sent"; leaf technology { type identityref { base technology-types; } description "The technology."; } leaf md-name-string { type leafref { path "/domains/domain/md-name-string"; } mandatory true; description "Indicate which Maintenance Domain (MD) does the defect belong to"; } leaf ma-name-string { type leafref { path "/domains/domain/mas/ma/ma-name-string"; } mandatory true; description "Indicate which Maintenance Association (MA) is the defect associated with."; } leaf mep-name { type leafref { path "/domains/domain/mas/ma/mep/mep-name"; } description "Indicate which Maintenance End Point (MEP) is seeing the defect."; } leaf defect-type { type identityref { base defect-types; } description "The currently active defects on the specific Maintenance End Point (MEP)."; } container generating-mepid { uses mep-id; description "Indicate who is generating the defect (if known). if unknown set it as 0."; } uses defect-message { description "Defect message to indicate more details."; } } rpc continuity-check { if-feature "continuity-check"; description "Generates continuity-check as per RFC7276 Table 4."; input { leaf technology { type identityref { base technology-types; } description "The technology"; } leaf md-name-string { type leafref { path "/domains/domain/md-name-string"; } mandatory true; description "Indicate which Maintenance Domain (MD) does the defect belong to."; } leaf md-level { type leafref { path "/domains/domain/md-level"; } description "The maintenance domain level."; } leaf ma-name-string { type leafref { path "/domains/domain/mas/ma/ma-name-string"; } mandatory true; description "Indicate which MA is the defect associated with"; } uses cos; uses time-to-live; leaf sub-type { type identityref { base command-sub-type; } description "Defines different command types."; } leaf source-mep { type leafref { path "/domains/domain/mas/ma/mep/mep-name"; } description "Source Maintenance End Point (MEP)."; } container destination-mep { uses mep-address; uses mep-id { description "Only applicable if the destination is a Maintenance End Point (MEP)."; } description "Destination Maintenance End Point (MEP)."; } leaf count { type uint32; default "3"; description "Number of continuity-check message to be sent."; } leaf cc-transmit-interval { type time-interval; description "Time interval between echo requests."; } leaf packet-size { type uint32 { range "64..10000"; } description "Size of continuity-check packets, in octets."; } } output { uses monitor-stats { description "Stats of continuity check."; } } } rpc continuity-verification { if-feature "connectivity-verification"; description "Generates continuity-verification as per RFC7276 Table 4."; input { leaf md-name-string { type leafref { path "/domains/domain/md-name-string"; } mandatory true; description "Indicate which MD (Maintenance Domain) does the defect belong to."; } leaf md-level { type leafref { path "/domains/domain/md-level"; } description "The maintenance domain level."; } leaf ma-name-string { type leafref { path "/domains/domain/mas/ma/ma-name-string"; } mandatory true; description "Indicate which Maintenance Association (MA) is the defect associated with."; } uses cos; uses time-to-live; leaf sub-type { type identityref { base command-sub-type; } description "Defines different command types."; } leaf source-mep { type leafref { path "/domains/domain/mas/ma/mep/mep-name"; } description "Source Maintenance End Point(MEP)."; } container destination-mep { uses mep-address; uses mep-id { description "Only applicable if the destination is a Maintenance End Point (MEP)."; } description "Destination Maintenance End Point(MEP)."; } leaf count { type uint32; default "3"; description "Number of continuity-verification message to be sent."; } leaf interval { type time-interval; description "Time interval between echo requests."; } leaf packet-size { type uint32 { range "64..10000"; } description "Size of continuity-verification packets, in octets"; } } output { uses monitor-stats { description "Stats of continuity check."; } } } rpc traceroute { if-feature "traceroute"; description "Generates Traceroute or Path Trace and return response. Referencing RFC7276 for common Toolset name, for MPLS-TP OAM, it's Route Tracing, and for TRILL OAM, it's Path Tracing tool. Starts with TTL of one and increment by one at each hop. Untill destination reached or TTL reach max value."; input { leaf md-name-string { type leafref { path "/domains/domain/md-name-string"; } mandatory true; description "Indicate which Maintenance Domain (MD) does the defect belong to."; } leaf md-level { type leafref { path "/domains/domain/md-level"; } description "The maintenance domain level."; } leaf ma-name-string { type leafref { path "/domains/domain/mas/ma/ma-name-string"; } mandatory true; description "Indicate which Maintenance Association (MA) is the defect associated with."; } uses cos; uses time-to-live; leaf command-sub-type { type identityref { base command-sub-type; } description "Defines different command types."; } leaf source-mep { type leafref { path "/domains/domain/mas/ma/mep/mep-name"; } description "Source Maintenance End Point (MEP)."; } container destination-mep { uses mep-address; uses mep-id { description "Only applicable if the destination is a Maintenance End Point (MEP)."; } description "Destination Maintenance End Point (MEP)."; } leaf count { type uint32; default "1"; description "Number of traceroute probes to send. In protocols where a separate message is sent at each TTL, this is the number of packets to be sent at each TTL."; } leaf interval { type time-interval; description "Time interval between echo requests."; } } output { list response { key "response-index"; leaf response-index { type uint8; description "Arbitrary index for the response. In protocols that guarantee there is only a single response at each TTL, the TTL can be used as the response index."; } uses time-to-live; container destination-mep { description "Maintenance End Point (MEP) from which the response has been received"; uses mep-address; uses mep-id { description "Only applicable if the destination is a Maintenance End Point (MEP)."; } } container mip { if-feature "mip"; leaf interface { type if:interface-ref; description "Maintenance Intermediate Point (MIP) interface."; } uses mip-address; description "Maintenance Intermediate Point (MIP) responding with traceroute"; } uses monitor-stats { description "Stats of traceroute."; } description "List of response."; } } } } <CODE ENDS>

The Base Mode ('default mode' described in section 4) defines default configuration that MUST be present in the devices that comply with this document. Base Mode allows users to have "zero-touch" experience. Several parameters require technology specific definition.

In the Base Mode of operation, the MEP Address is by default the IP address of the interface on which the MEP is located.

In the Base Mode of operation, each device creates a single MEP associated with a virtual OAM port with no physical layer (NULL PHY). The MEP-ID associated with this MEP is zero (0). The choice of MEP-ID zero is explained below. MEP-ID is 2 octet field by default. It is never used on the wire except when using CCM. It is important to have method that can derive MEP-ID of base mode in an automatic manner with no user intervention. IP address cannot be directly used for this purpose as the MEP-ID is much smaller field. For Base Mode of operation MEP-ID zero (0) is set as the default MEP-ID. CCM packet use MEP-ID on the payload. CCM MUST NOT be used in the Base Mode. Hence CCM MUST be disabled on the Maintenance Association of the Base Mode. If CCM is required, users MUST configure a separate Maintenance association and assign unique value for the corresponding MEP IDs. CFM defines MEP ID as an unsigned integer in the range 1 to 8191. In this document we propose extend the range to 0 to 65535. Value 0 is reserved for MEP-ID of Base Mode operation and MUST NOT be used for other purposes.

The ID of the Maintenance Association (MA-ID) has a flexible format and includes two parts: Maintenance Domain Name and Short MA name. In the Base Mode of operation, the value of the Maintenance Domain Name must be the character string "GenericBaseMode" (excluding the quotes "). In the Base Mode operation, the Short MA Name format is set to 2-octet integer format (value 3 in Short MA Format field ) and the Short MA name set to 65532 (0xFFFC).

"ietf-connection-oriented-oam" model defined in this document provides technology-independent abstraction of key OAM constructs for connection-oriented protocols. This model can be further extended to include technology specific details, e.g., adding new data nodes with technology specific functions and parameters into proper anchor points of the base model, so as to develop a technology-specific connection-oriented OAM model. This section demonstrates the usability of the connection-oriented YANG OAM data model to various connection-oriented OAM technologies, e.g., TRILL and MPLS-TP. Note that, in this section, we only present several snippets of technology-specific model extensions for illustrative purposes. The complete model extensions should be worked on in respective protocol working groups.

The TRILL OAM YANG module (I-D.trill-yang-oam) is augmenting connection-oriented OAM module for both configuration and RPC commands. In addition,the TRILL OAM YANG module also requires the base TRILL module ([I-D.ietf-trill-yang]) to be supported as there is a strong relationship between those modules. The configuration extensions for connection-oriented OAM include MD configuration extension, Technology type extension, MA configuration extension, Connectivity-Context Extension, MEP Configuration Extension, ECMP extension. In the RPC extension, the continuity-check and path-discovery RPC are extended with TRILL specific parameters.

MD level configuration parameters are management information which can be inherited in the TRILL OAM model and set by connection-oriented base model as default values. For example domain name can be set to area-ID in the TRILL OAM case. In addition, at the Maintenance Domain level (i.e., at root level), domain data node can be augmented with technology type. Note that MD level configuration parameters provides context information for the management system to correlate faults, defects, network failures with location information, which helps quickly identify root causes of network failures.

No TRILL technology type has been defined in the connection-oriented base model. Therefore a technology type extension is required in the TRILL OAM model. The technology type "trill" is defined as an identity that augments the base "technology-types" defined in the connection-oriented base model:

identity trill{ base co-oam:technology-types; description "trill type"; }

MA level configuration parameters are management information which can be inherited in the TRILL OAM model and set by connection-oriented base model as default values. In addition, at the Maintenance Association(MA) level (i.e.,at the second level), MA data node can be augmented with connectivity-context extension. Note that MA level configuration parameters provides context information for the management system to correlate faults, defects, network failures with location information, which helps quickly identify root causes of network failures.

In TRILL OAM, one example of connectivity-context is either a 12 bit VLAN ID or a 24 bit Fine Grain Label. The connection-oriented base model defines a placeholder for context-id. This allows other technologies to easily augment that to include technology specific extensions. The snippet below depicts an example of augmenting connectivity-context to include either VLAN ID or Fine Grain Label.

augment /co-oam:domains/co-oam:domain /co-oam:mas/co-oam:ma/co-oam:connectivity-context: +--:(connectivity-context-vlan) | +--rw connectivity-context-vlan? vlan +--:(connectivity-context-fgl) +--rw connectivity-context-fgl? fgl

The MEP configuration definition in the connection-oriented base model already supports configuring the interface of MEP with either MAC address or IP address. In addition, the MEP address can be represented using a 2 octet RBridge Nickname in TRILL OAM . Hence, the TRILL OAM model augments the MEP configuration in base model to add a nickname case into the MEP address choice node as follows:

augment /co-oam:domains/co-oam:domain /co-oam:mas/co-oam:ma/co-oam:mep/co-oam:mep-address: +--:( mep-address-trill) | +--rw mep-address-trill? tril-rb-nickname In addition, at the Maintenance Association Endpoint(MEP) level (i.e.,at the third level), MEP data node can be augmented with ECMP extension.

Since TRILL supports ECMP path selection, flow-entropy in TRILL is defined as a 96 octet field in the LIME model extension for TRILL OAM. The snippet below illustrates its extension.

augment /co-oam:domains/co-oam:domain /co-oam:mas/co-oam:ma/co-oam:mep: +--rw flow-entropy-trill? flow-entropy-trill augment /co-oam:domains/co-oam:domain /co-oam:mas/co-oam:ma/co-oam:mep/co-oam:session: +--rw flow-entropy-trill? flow-entropy-trill

In the TRILL OAM YANG model, the continuity-check and path-discovery RPC commands are extended with TRILL specific requirements. The snippet below depicts an example of illustrates the TRILL OAM RPC extension.

augment /co-oam:continuity-check/co-oam:input: +--ro (out-of-band)? | +--:(ipv4-address) | | +--ro ipv4-address? inet:ipv4-address | +--:(ipv6-address) | | +--ro ipv6-address? inet:ipv6-address | +--:(trill-nickname) | +--ro trill-nickname? tril-rb-nickname +--ro diagnostic-vlan? boolean augment /co-oam:continuity-check/co-oam:input: +--ro flow-entropy-trill? flow-entropy-trill augment /co-oam:continuity-check/co-oam:output: +--ro upstream-rbridge? tril-rb-nickname +--ro next-hop-rbridge* tril-rb-nickname augment /co-oam:path-discovery/co-oam:input: +--ro (out-of-band)? | +--:(ipv4-address) | | +--ro ipv4-address? inet:ipv4-address | +--:(ipv6-address) | | +--ro ipv6-address? inet:ipv6-address | +--:(trill-nickname) | +--ro trill-nickname? tril-rb-nickname +--ro diagnostic-vlan? boolean augment /co-oam:path-discovery/co-oam:input: +--ro flow-entropy-trill? flow-entropy-trill augment /co-oam:path-discovery/co-oam:output/co-oam:response: +--ro upstream-rbridge? tril-rb-nickname +--ro next-hop-rbridge* tril-rb-nickname

The MPLS-TP OAM YANG module can augment the connection-oriented OAM Module with some technology-specific details. And the presents the YANG Data model for MPLS-TP OAM. The configuration extensions for connection-oriented OAM include MD configuration extension, Technology type extension, Sub Technology Type Extension, MA configuration extension, MEP Configuration Extension.

MD level configuration parameters are management information which can be inherited in the MPLS-TP OAM model and set by the connection-oriented OAM base model as default values. For example domain name can be set to area-ID or the provider's Autonomous System Number(ASN) in the MPLS-TP OAM case. In addition, at the Maintenance Domain level (i.e.,at root level), domain data node can be augmented with technology type and sub-technology type. Note that MD level configuration parameters provides context information for the management system to correlate faults, defects, network failures with location information, which helps quickly identify root causes of network failures

No MPLS-TP technology type has been defined in the connection-oriented base model, hence it is required in the MPLS-TP OAM model. The technology type "mpls-tp" is defined as an identity that augments the base "technology-types" defined in the connection-oriented base model:

identity mpls-tp{ base co-oam:technology-types; description "mpls-tp type"; }

In MPLS-TP, since different encapsulation types such as IP/UDP Encapsulation, PW-ACH encapsulation can be employed, the "technology- sub-type" data node is defined and added into the MPLS-TP OAM model to further identify the encapsulation types within the MPLS-TP OAM model. Based on it, we also define a technology sub-type for IP/UDP encapsulation and PW-ACH encapsulation. Other Encapsulation types can be defined in the same way. The snippet below depicts an example of several encapsulation types.

identity technology-sub-type { description "certain implementations can have different encapsulation types such as ip/udp, pw-ach and so on. Instead of defining separate models for each encapsulation, we define a technology sub-type to further identify different encapsulations. Technology sub-type is associated at the MA level"; } identity technology-sub-type-udp { base technology-sub-type; description "technology sub-type is IP/UDP encapsulation"; } identity technology-sub-type-ach { base technology-sub-type; description "technology sub-type is PW-ACH encapsulation"; } } augment "/co-oam:domains/co-oam:domain" +"/co-oam:mas/co-oam:ma { leaf technology-sub-type { type identityref { base technology-sub-type; } } }

MA level configuration parameters are management information which can be inherited in the MPLS-TP OAM model and set by the connection-oriented OAM base model as default values. One example of MA Name could be MEG LSP ID or MEG Section ID or MEG PW ID[RFC6370]. Note that MA level configuration parameters provides context information for the management system to correlate faults, defects, network failures with location information, which helps quickly identify root causes of network failures.

In MPLS-TP, MEP-ID is either a variable length label value in case of G-ACH encapsulation or a 2 octet unsigned integer value in case of IP/UDP encapsulation. One example of MEP-ID is MPLS-TP LSP_MEP_ID [RFC6370]. In the connection-oriented base model, MEP-ID is defined as a choice/case node which can supports an int32 value, and the same definition can be used for MPLS-TP with no further modification. In addition, at the Maintenance Association Endpoint(MEP) level (i.e.,at the third level), MEP data node can be augmented with Session extension and interface extension.

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 or RESTCONF . The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) . The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS . The NETCONF access control model 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. There are a number of data nodes defined in the YANG module which are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive in some network environments. Write operations (e.g., <edit&nbhy;config>) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability:

/co-oam:domains/co-oam:domain/ /co-oam:domains/co-oam:domain/co-oam:mas/co-oam:ma /co-oam:domains/co-oam:domain/co-oam:mas/co-oam:ma/co-oam:mep /co-oam:domains/co-oam:domain/co-oam:mas/co-oam:ma/co-oam:mep/ co-oam:session Unauthorized access to any of these lists can adversely affect OAM management system handling of end-to-end OAM and coordination of OAM within underlying network layers This may lead to inconsistent configuration, reporting, and presentation for the OAM mechanisms used to manage the network.

This document registers a URI in the IETF XML registry . Following the format in RFC 3688, the following registration is requested to be made:

URI: urn:ietf:params:xml:ns:yang:ietf-connection-oriented-oam Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. This document registers a YANG module in the YANG Module Names registry .

name: ietf-connection-oriented-oam namespace: urn:ietf:params:xml:ns:yang:ietf-connection-oriented-oam prefix: co-oam reference: RFC XXXX

Giles Heron came up with the idea of developing a YANG model as a way of creating a unified OAM API set (interface), work in this document is largely an inspiration of that. Alexander Clemm provided many valuable tips, comments and remarks that helped to refine the YANG model presented in this document. Carlos Pignataro, David Ball,Mahesh Jethanandani,Benoit Claise,Ladislav Lhotka,GUBALLA JENS,Yuji Tochio,Gregory Mirsky, Huub van Helvoort, Tom Taylor, Dapeng Liu,Mishael Wexler, Adi Molkho participated and contributed to this document.

Key words for use in RFCs to Indicate Requirement Levels In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Connectivity Fault Management Unified functional architecture of transport networks OAM functions and mechanisms for Ethernet based networks Service OAM Requirements & Framework – Phase 1 YANG Data Model for MPLS-TP Operations, Administration, and Maintenance

Tissa Senevirathne Consultant Email: tsenevir@gmail.com Norman Finn CISCO Systems 510 McCarthy Blvd Milpitas, CA 95035 USA Email: nfinn@cisco.com Samer Salam CISCO Systems 595 Burrard St. Suite 2123 Vancouver, BC V7X 1J1 Canada Email: ssalam@cisco.com