LIME Tissa Senevirathne Internet Draft Norman Finn Intended status: Standards Track Deepak Kumar Samer Salam Cisco Qin Wu HuaWei October 25, 2014 Expires: April 2015 Generic YANG Data Model for Operations, Administration, and Maintenance (OAM) draft-tissa-lime-yang-oam-model-02.txt Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." 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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. Abstract This document presents base YANG Data model for OAM. It provides a protocol-independent and technology-independent abstraction of key OAM constructs. Based model presented here can be extended to include technology specific details. Leading to uniformity between OAM technologies and support nested OAM workflows (i.e., performing OAM functions at different layers through a unified interface). Table of Contents 1. Introduction...................................................3 2. Conventions used in this document..............................4 2.1. Terminology...............................................4 3. Architecture of Generic YANG Model for OAM.....................5 4. Overview of the OAM Model......................................6 4.1. Maintenance Domain (MD) configuration.....................7 4.2. Maintenance Association (MA) configuration................8 4.3. Maintenance Endpoint (MEP) configuration..................9 4.4. rpc definitions...........................................9 5. OAM data hierarchy............................................11 6. OAM YANG module...............................................16 7. Base Mode for IP..............................................32 7.1. MEP Address..............................................32 7.2. MEP ID for Base Mode.....................................32 7.3. Maintenance Domain.......................................33 7.4. Maintenance Association..................................33 8. Security Considerations.......................................33 9. IANA Considerations...........................................33 10. References...................................................33 10.1. Normative References....................................33 10.2. Informative References..................................33 11. Acknowledgments..............................................34 12. Contributors.................................................35 Senevirathne Expires April 25, 2015 [Page 2] Internet-Draft YANG Data Model for Generic OAM October 2014 1. Introduction Operations, Administration, and Maintenance (OAM) are important networking functions that allow operators to: 1. Monitor networks (Connectivity Verification, Continuity Check) 2. Troubleshoot failures (Fault verification and isolation). 3. Measure Performance An overview of OAM tools is presented at [OAMOVW]. Ping and Traceroute [RFC792], [RFC4443] are well-known fault verification and isolation tools, respectively, for IP networks. Over the years different technologies have developed similar tools for similar purposes. [8021Q] Connectivity Fault Management is a well-established OAM standard that is widely adopted for Ethernet networks. ITU-T [Y1731], MEF Service OAM, MPLS-TP [RFC6371], TRILL [TRILLOAMFM] all define OAM methods based on manageability frame work of [8021Q] CFM. Given the wide adoption of the underlying OAM concepts defined in [8021Q] CFM, it is a reasonable choice to develop the unified management framework based on those concepts. In this document, we take the [8021Q] CFM model and extend it to a technology independent framework and build the corresponding YANG model accordingly. The YANG model presented in this document is the base model and supports IP Ping and Traceroute. The generic OAM YANG model is designed such that it can be extended to cover various technologies. Technology dependent nodes and 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 MPLS [RFC4379] uses IP addresses or the label stack 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 purposes: first it keeps each YANG model smaller and 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 OAM model and the TRILL YANG model). All implementations that follow the YANG framework presented in this document MUST implement the generic OAM YANG model presented here. Senevirathne Expires April 25, 2015 [Page 3] Internet-Draft YANG Data Model for Generic OAM October 2014 The YANG data model presented in this document occurs at the management layer. Encapsulations and state machines may differ according to each OAM protocol. A user who wishes to issues a Ping command or a Traceroute 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 an IP ping from device A to Device B failed. Between device A and B there are IEEE 802.1 bridges a,b and c. Let's assume a,b and c are using [8021Q] CFM. A user upon detecting the IP layer ping failures may decide to drill down to the Ethernet layer and issue the corresponding fault verification (LBM) and fault isolation (LTM) tools, using the same API. This ability to go up and down to different layers for troubleshooting is referred to as "nested OAM workflow" and is a useful concept that leads to efficient network troubleshooting and maintenance. The OAM YANG model presented in this document facilitates that without needing changes to the underlying protocols. 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC-2119 [RFC2119]. In this document, these words will appear with that interpretation only when in ALL CAPS. Lower case uses of these words are not to be interpreted as carrying RFC-2119 significance. 2.1. Terminology CCM - Continuity Check Message [8021Q] ECMP - Equal Cost Multipath LBM - Loopback Message [8021Q] MP - Maintenance Point [8021Q] MEP - Maintenance End Point [RFC7174] [8021Q] [RFC6371] MIP - Maintenance Intermediate Point [RFC7174] [8021Q] [RFC6371] MA - Maintenance Association [8021Q] [RFC7174] MD - Maintenance Domain [8021Q] Senevirathne Expires April 25, 2015 [Page 4] Internet-Draft YANG Data Model for Generic OAM October 2014 MTV - Multi-destination Tree Verification Message OAM - Operations, Administration, and Maintenance [RFC6291] TRILL - Transparent Interconnection of Lots of Links [RFC6325] 3. Architecture of Generic YANG Model for OAM In this document we define a generic YANG model for OAM. The YANG model defined here is generic such that other technologies can extend it for technology specific needs. The Generic OAM YANG model acts as the root for other OAM YANG models. This allows users to traverse between OAM of different technologies at ease through a uniform API set. This is also provides a nested OAM workflow. Figure 1 depicts the relationship of different OAM YANG models to the Generic OAM YANG Model. Some technologies may have different sub-technologies. As an example, consider Network Virtualization Overlays. These could employ either vXLAN or NVGRE as encapsulation. The Generic OAM YANG model 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. Figure 1 depicts relationship of different YANG modules. Senevirathne Expires April 25, 2015 [Page 5] Internet-Draft YANG Data Model for Generic OAM October 2014 +-+-+-+-+-+ | gen | |OAM YANG | +-+-+-+-+-+ | O | +---------------------------------------------------------+ | | | | | +-+-+-+-+-+ +-+-+-+-+-+ +-+-+-+-+-+ +-+-+-+-+-+ +-+-+-+-+-+ | TRILL | | NVO3 | | MPLS | | IP | . . .| foo | |OAM YANG | |OAM YANG | |OAM YANG | |OAM YANG | |OAM YANG | +-+-+-+-+-+ +-+-+-+-+-+ +-+-+-+-+-+ +-+-+-+-+-+ +-+-+-+-+-+ | | | | | | +-+-+-+-+-+ +-+-+-+-+-+ | +-+-+-+-+-+ | | NVO3 | | MPLS | | . . .| foo | | |sub tech | |sub tech | | |sub tech | | +-+-+-+-+-+ +-+-+-+-+-+ | +-+-+-+-+-+ | | | | | | | | | | +------------------------------------------------------------+ | Uniform API | +------------------------------------------------------------+ Figure 1 Relationship of OAM YANG model to generic (base) YANG model 4. Overview of the OAM Model In this document we adopt the concepts of the [8021Q] CFM model and structure it such that it can be adapted to different technologies. 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 Association (MA). In IP, the MA can be per IP Subnet, in NVO3 this can be per VNI and for TRILL this can be per Fine-Grained Label or for VPLS this can be per VPLS instance. 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. Senevirathne Expires April 25, 2015 [Page 6] Internet-Draft YANG Data Model for Generic OAM October 2014 In a parallel vertical, presented are the commands. Those, in YANG terms, are the rpc commands. These rpc commands provide uniform APIs for ping, traceroute and their equivalents as well as other OAM commands. [8021Q] CFM framework requires explicit configuration of OAM entities prior to using any of the OAM tools. Users of Ping and Traceroute tools within IP devices are expecting ability to use OAM tools with no explicit configuration. 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 the [8021Q] CFM parameters, such as Maintenance Domain Level, Name of the Maintenance Association and Addresses of MEP and so on. The default values of these depend on the technology. Base Mode for TRILL is defined in [TRILLOAMFM]. Section 7. of this document specifies the Base mode for IP devices. Base mode for other technologies such as NVO3, MPLS and future extensions 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. 4.1. Maintenance Domain (MD) configuration The container "domains" is the top level container within the gen-oam module. Within the container "domains", separate list is maintained per MD. The MD list uses the key MD-name-string for indexing. MD- name-string is a leaf and derived from type string. Additional name formats as defined in [8021Q] or other standards can be included by association of the MD-name-format with an identity-ref. MD-name- format indicates the format of the augmented MD-names. MD-name is presented as choice/case construct. Thus, it is easily augmentable by derivative work. Senevirathne Expires April 25, 2015 [Page 7] Internet-Draft YANG Data Model for Generic OAM October 2014 module: gen-oam-db +--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 . . Figure 1 Snippet of data hierarchy related to OAM domains 4.2. Maintenance Association (MA) configuration Within a given Maintenance Domain there can be one or more Maintenance Associations (MA). 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-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 Figure 2 Snippet of data hierarchy related to Maintenance Associations (MA). Senevirathne Expires April 25, 2015 [Page 8] Internet-Draft YANG Data Model for Generic OAM October 2014 4.3. Maintenance Endpoint (MEP) configuration 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. module: gen-oam +--rw domains +--rw domain* [technology MD-name-string] +--rw technology identityref . . +--rw MAs +--rw MA* [MA-name-string] +--rw MA-name-string MA-name-string . . +--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 (mp-address)? | | +--:(mac-address) | | | +--rw mac-address? yang:mac-address | | +--:(ipv4-address) | | | +--rw ipv4-address? inet:ipv4-address | | +--:(ipv6-address) | | +--rw ipv6-address? inet:ipv6-address . . . . . . Figure 3 Snippet of data hierarchy related to Maintenance Endpoint (MEP). 4.4. rpc definitions The rpc model facilitates issuing commands to a NETCONF server (in this case to the device that need to execute the OAM command) and obtain 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 ping command for Senevirathne Expires April 25, 2015 [Page 9] Internet-Draft YANG Data Model for Generic OAM October 2014 illustration purposes. Please refer to Section 4 for the complete data hierarchy and Section 5 for the YANG model. module: ietf-oam +--rw domains +--rw domain* [technology MD-name-string] +--rw technology identityref . . rpcs: +---x ping | +--ro input | | +--ro MA-name-string? MA-name-string | | +--ro (flow-entropy)? | | | +--:(flow-entropy-null) | | | +--ro flow-entropy-null? empty | | +--ro priority? uint8 | | +--ro ttl? uint8 | | +--ro ecmp-choice? ecmp-choices | | +--ro sub-type? identityref | | +--ro outgoing-interfaces* [interface] | | | +--ro interface if:interface-ref | | +--ro source-mep? MEP-name | | +--ro destination-mp | | | +--ro (mp-address)? | | | | +--:(mac-address) | | | | | +--ro mac-address? yang:mac-address | | | | +--:(ipv4-address) | | | | | +--ro ipv4-address? inet:ipv4-address | | | | +--:(ipv6-address) | | | | +--ro ipv6-address? inet:ipv6-address | | | +--ro (MEP-ID)? | | | | +--:(MEP-ID-int) | | | | +--ro MEP-ID-int? int32 | | | +--ro MEP-ID-format? identityref | | +--ro count? uint32 | | +--ro interval? Interval | | +--ro packet-size? uint32 | +--ro output | +--ro tx-packt-count? oam-counter32 | +--ro rx-packet-count? oam-counter32 | +--ro min-delay? oam-counter32 | +--ro average-delay? oam-counter32 | +--ro max-delay? oam-counter32 Figure 4 Snippet of data hierarchy related to rpc call Ping Senevirathne Expires April 25, 2015 [Page 10] Internet-Draft YANG Data Model for Generic OAM October 2014 5. OAM data hierarchy The complete data hierarchy related to the OAM YANG model is presented below. The following notations are used within the data tree and carry the meaning as below. Each node is printed as: is one of: + for current x for deprecated o for obsolete is one of: rw for configuration data ro for non-configuration data -x for rpcs -n for notifications is the name of the node If the node is augmented into the tree from another module, its name is printed as :. is one of: ? for an optional leaf or choice ! for a presence container * for a leaf-list or list [] for a list's keys is the name of the type for leafs and leaf-lists Senevirathne Expires April 25, 2015 [Page 11] Internet-Draft YANG Data Model for Generic OAM October 2014 module: gen-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 mep-direction MEP-direction +--rw interval? Interval +--rw loss-threshold? uint32 +--rw ttl? uint8 +--rw (flow-entropy)? | +--:(flow-entropy-null) | +--rw flow-entropy-null? empty +--rw priority? uint8 +--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 (mp-address)? | | +--:(mac-address) | | | +--rw mac-address? yang:mac-address | | +--:(ipv4-address) | | | +--rw ipv4-address? inet:ipv4-address | | +--:(ipv6-address) | | +--rw ipv6-address? inet:ipv6-address | +--rw (connectivity-context)? | | +--:(context-null) | | +--rw context-null? empty | +--rw Interface? if:interface-ref | +--ro admin-status? leafref Senevirathne Expires April 25, 2015 [Page 12] Internet-Draft YANG Data Model for Generic OAM October 2014 | +--ro oper-status? leafref | +--rw (flow-entropy)? | | +--:(flow-entropy-null) | | +--rw flow-entropy-null? empty | +--rw priority? uint8 | +--rw session* [session-cookie] | +--rw session-cookie uint32 | +--rw ttl? uint8 | +--rw interval? Interval | +--rw enable? boolean | +--rw ecmp-choice? ecmp-choices | +--rw source-mep? MEP-name | +--rw destination-mep | | +--rw (MEP-ID)? | | | +--:(MEP-ID-int) | | | +--rw MEP-ID-int? int32 | | +--rw MEP-ID-format? identityref | +--rw destination-mep-address | | +--rw (mp-address)? | | +--:(mac-address) | | | +--rw mac-address? yang:mac-address | | +--:(ipv4-address) | | | +--rw ipv4-address? inet:ipv4-address | | +--:(ipv6-address) | | +--rw ipv6-address? inet:ipv6-address | +--rw (connectivity-context)? | | +--:(context-null) | | +--rw context-null? empty | +--rw (flow-entropy)? | | +--:(flow-entropy-null) | | +--rw flow-entropy-null? empty | +--rw priority? uint8 | +--rw outgoing-interface* [interface] | +--rw interface leafref +--rw MIP* [interface] | +--rw interface if:interface-ref +--rw related-oam-layer* [offset] +--rw offset int32 +--rw MA-name-string? MA-name-string rpcs: +---x ping | +--ro input | | +--ro MA-name-string? MA-name-string | | +--ro (flow-entropy)? | | | +--:(flow-entropy-null) | | | +--ro flow-entropy-null? empty | | +--ro priority? uint8 Senevirathne Expires April 25, 2015 [Page 13] Internet-Draft YANG Data Model for Generic OAM October 2014 | | +--ro ttl? uint8 | | +--ro ecmp-choice? ecmp-choices | | +--ro sub-type? identityref | | +--ro outgoing-interfaces* [interface] | | | +--ro interface if:interface-ref | | +--ro source-mep? MEP-name | | +--ro destination-mp | | | +--ro (mp-address)? | | | | +--:(mac-address) | | | | | +--ro mac-address? yang:mac-address | | | | +--:(ipv4-address) | | | | | +--ro ipv4-address? inet:ipv4-address | | | | +--:(ipv6-address) | | | | +--ro ipv6-address? inet:ipv6-address | | | +--ro (MEP-ID)? | | | | +--:(MEP-ID-int) | | | | +--ro MEP-ID-int? int32 | | | +--ro MEP-ID-format? identityref | | +--ro count? uint32 | | +--ro interval? Interval | | +--ro packet-size? uint32 | +--ro output | +--ro tx-packt-count? oam-counter32 | +--ro rx-packet-count? oam-counter32 | +--ro min-delay? oam-counter32 | +--ro average-delay? oam-counter32 | +--ro max-delay? oam-counter32 +---x trace-route +--ro input | +--ro MA-name-string? MA-name-string | +--ro (flow-entropy)? | | +--:(flow-entropy-null) | | +--ro flow-entropy-null? empty | +--ro priority? uint8 | +--ro ttl? uint8 | +--ro command-sub-type? identityref | +--ro ecmp-choice? ecmp-choices | +--ro outgoing-interfaces* [interface] | | +--ro interface if:interface-ref | +--ro source-mep? MEP-name | +--ro destination-mp | | +--ro (mp-address)? | | | +--:(mac-address) | | | | +--ro mac-address? yang:mac-address | | | +--:(ipv4-address) | | | | +--ro ipv4-address? inet:ipv4-address | | | +--:(ipv6-address) Senevirathne Expires April 25, 2015 [Page 14] Internet-Draft YANG Data Model for Generic OAM October 2014 | | | +--ro ipv6-address? inet:ipv6-address | | +--ro (MEP-ID)? | | | +--:(MEP-ID-int) | | | +--ro MEP-ID-int? int32 | | +--ro MEP-ID-format? identityref | +--ro count? uint32 | +--ro interval? Interval +--ro output +--ro response* [response-index] +--ro response-index uint8 +--ro ttl? uint8 +--ro destination-mp | +--ro (mp-address)? | | +--:(mac-address) | | | +--ro mac-address? yang:mac-address | | +--:(ipv4-address) | | | +--ro ipv4-address? inet:ipv4-address | | +--:(ipv6-address) | | +--ro ipv6-address? inet:ipv6-address | +--ro (MEP-ID)? | | +--:(MEP-ID-int) | | +--ro MEP-ID-int? int32 | +--ro MEP-ID-format? identityref +--ro tx-packt-count? oam-counter32 +--ro rx-packet-count? oam-counter32 +--ro min-delay? oam-counter32 +--ro average-delay? oam-counter32 +--ro max-delay? oam-counter32 notifications: +---n RDI-notification +--ro MA-name-string? MA-name-string +--ro mep-name? MEP-name +--ro remote-mepid | +--ro (MEP-ID)? | | +--:(MEP-ID-int) | | +--ro MEP-ID-int? int32 | +--ro MEP-ID-format? identityref +--ro error-message? string Figure 5 data hierarchy of OAM Senevirathne Expires April 25, 2015 [Page 15] Internet-Draft YANG Data Model for Generic OAM October 2014 6. OAM YANG module file "xxx.yang" module gen-oam { namespace "urn:ietf:params:xml:ns:yang:gen-oam"; prefix goam; import ietf-interfaces { prefix if; } import ietf-yang-types { prefix yang; } import ietf-inet-types { prefix inet; } organization "IETF LIME Working Group"; contact "Tissa Senevirathne tsenevir@cisco.com"; description "This YANG module defines the generic configuration, statistics and rpc for OAM to be used within IETF in a protocol indpendent manner. Functional level abstraction is indendent with YANG modeling. It is assumed that each protocol maps corresponding abstracts to its native format. Each protocoal may extend the YANG model defined here to include protocol specific extensions"; revision 2014-10-17 { description "Initial revision. - 02 version"; reference "draft-tissa-lime-oam"; } identity technology-types { description "this is the base identy of technology types which are vpls, nvo3, TRILL, ipv4, ipv6, mpls, etc"; } identity ipv4 { base technology-types; description "technology of ipv4"; Senevirathne Expires April 25, 2015 [Page 16] Internet-Draft YANG Data Model for Generic OAM October 2014 } identity ipv6 { base technology-types; description "technology of ipv6"; } identity command-sub-type { description "defines different rpc command subtypes, e.g rfc792 ping vs udp ping, this is optional for most cases"; } identity icmp-rfc792 { base command-sub-type; description "Defines the command subtypes for ICMP ping"; reference "RFC 792"; } identity name-format { description "This defines the name format, IEEE 8021Q 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 MEPD-ID etc"; } identity identifier-format-integer { base identifier-format; description "defines identifier-format to be integer"; } typedef MEP-direction { Senevirathne Expires April 25, 2015 [Page 17] Internet-Draft YANG Data Model for Generic OAM October 2014 type enumeration { enum "Up" { value 0; } enum "Down" { value 1; } } } typedef MEP-name { type string; description "Generic administrative name for a MEP"; } typedef Interval { type uint32; units "milliseconds"; default "1000"; description "Interval between packets in milliseconds. 0 means no packets are sent."; } typedef ecmp-choices { type enumeration { enum "ecmp-use-platform-hash" { value 0; } enum "ecmp-use-round-robin" { value 1; } } } typedef MD-name-string { default ""; type string; description "Generic administrative name for an MD"; } typedef MA-name-string { default ""; type string; description Senevirathne Expires April 25, 2015 [Page 18] Internet-Draft YANG Data Model for Generic OAM October 2014 "Generic administrative name for an MA"; } typedef oam-counter32 { type yang:zero-based-counter32; description "defines 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 (eg to 0-7)"; } grouping mp-address { choice mp-address { case mac-address { leaf mac-address { type yang:mac-address; } } case ipv4-address { leaf ipv4-address { type inet:ipv4-address; } } case ipv6-address { leaf ipv6-address { type inet:ipv6-address; } } } } grouping maintenance-domain-id { status current; description "Grouping containing leaves sufficient to identify an MD"; leaf technology { status current; type identityref { base technology-types; } Senevirathne Expires April 25, 2015 [Page 19] Internet-Draft YANG Data Model for Generic OAM October 2014 mandatory true; description "Defines the technology"; } leaf MD-name-string { status current; description "Defines the generic administrative maintenance domain name"; type MD-name-string; mandatory true; } } grouping MD-name { leaf MD-name-format { type identityref { base name-format; } } choice MD-name { case MD-name-null { leaf MD-name-null { when "../../../MD-name-format = name-format-null"; type empty; } } } } grouping ma-identifier { description "Grouping containing leaves sufficient to identify an MA"; leaf MA-name-string { type MA-name-string; } } grouping MA-name { leaf MA-name-format { type identityref { base name-format; } } choice MA-name { case MA-name-null { Senevirathne Expires April 25, 2015 [Page 20] Internet-Draft YANG Data Model for Generic OAM October 2014 leaf MA-name-null { when "../../../MA-name-format = name-format-null"; type empty; } } } } grouping MEP-ID { choice MEP-ID { default "MEP-ID-int"; case MEP-ID-int { leaf MEP-ID-int { type int32; } } } leaf MEP-ID-format { type identityref { base identifier-format; } } } grouping MEP { status current; description "Defines elements within the MEP"; leaf mep-name { mandatory true; type MEP-name; status current; description "Generic administrative name of the MEP"; } uses MEP-ID; uses mp-address; uses connectivity-context; leaf Interface { type if:interface-ref; description "Interface name as defined by ietf-interfaces"; Senevirathne Expires April 25, 2015 [Page 21] Internet-Draft YANG Data Model for Generic OAM October 2014 } } grouping monitor-stats { leaf tx-packt-count { type oam-counter32; description "Transmitted Packet count"; } leaf rx-packet-count { type oam-counter32; description "Received packet count"; } leaf min-delay { units "milliseconds"; type oam-counter32; description "Delay is specified in milliseconds"; } leaf average-delay { units "milliseconds"; type oam-counter32; description "average delay in milliseconds"; } leaf max-delay { type oam-counter32; units "millisecond"; } } grouping MIP { description "defines MIP"; leaf interface { type if:interface-ref; } } grouping related-oam-layer { leaf offset { type int32 { range "-255..255"; } description "defines offset (in MD levels) to a related OAM layer Senevirathne Expires April 25, 2015 [Page 22] Internet-Draft YANG Data Model for Generic OAM October 2014 +1 is the layer immediately above -1 is the layer immediately below"; } uses ma-identifier; } grouping interface-status { description "collection of interface related status"; leaf admin-status { config false; type leafref { path "/if:interfaces-state/if:interface/if:admin-status"; } description "oper status from ietf-interface module"; } leaf oper-status { config false; type leafref { path "/if:interfaces-state/if:interface/if:oper-status"; } description "oper status from ietf-interface module"; } } grouping connectivity-context { description "Grouping defining the connectivity context for an MA; for example, a VRF for IP, or an LSP for MPLS. 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 define"; } } } } grouping priority { Senevirathne Expires April 25, 2015 [Page 23] Internet-Draft YANG Data Model for Generic OAM October 2014 description "Priority used in transmitted packets; for example, in the TOS/DSCP field in IP or the Traffic Class field in MPLS"; leaf priority { type uint8; } } grouping flow-entropy { description "defines the grouping statement for flow-entropy"; choice flow-entropy { default "flow-entropy-null"; case flow-entropy-null { description "this is a place holder when no flow entropy is needed"; leaf flow-entropy-null { type empty; description "there is no flow entropy defined"; } } } } container domains { status current; config true; description "Contains configuration related data. Within the container is list of fault domains. Wihin each domian has List of MA."; list domain { key "technology MD-name-string"; ordered-by system; status current; config true; description "Define the list of Domains within the IETF-OAM"; uses maintenance-domain-id; uses MD-name; leaf md-level { mandatory true; status current; description "Defines the MD-Level"; type MD-level; } Senevirathne Expires April 25, 2015 [Page 24] Internet-Draft YANG Data Model for Generic OAM October 2014 container MAs { status current; config true; description "This container defines MA, within that have multiple MA and within MA have MEP, MIP"; list MA { ordered-by system; status current; config true; key "MA-name-string"; uses ma-identifier; uses MA-name; uses connectivity-context; leaf mep-direction { type MEP-direction; mandatory true; description "Direction for MEPs in this MA"; } leaf interval { default "0"; description "Defines default Keepalive/CC Interval. May be overridden for specific sessions if supported by the protocol."; type Interval; } leaf loss-threshold { default "3"; type uint32; description "number of consecutive Keepalive/CC messages missed before declaring loss of continuity fault. This is monitored per each remote MEP session"; } leaf ttl { type uint8; default "255"; } uses flow-entropy { description "Default flow entropy in this MA, which may be overridden for particular MEPs, sessions or operations"; } uses priority { Senevirathne Expires April 25, 2015 [Page 25] Internet-Draft YANG Data Model for Generic OAM October 2014 description "Default priority for this MA, which may be overridden for particular MEPs, sessions or operations."; } list MEP { key "mep-name"; ordered-by system; status current; config true; description "contain list of MEPS"; uses MEP { status current; } uses interface-status { description "status of associated interface"; } uses flow-entropy; uses priority; list session { key "session-cookie"; ordered-by user; config true; description "Monitoring session to/from a particular remote MEP. Depending on the protocol, this could represent 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 { config true; type uint32; description "Cookie to identify different sessions, when there are multiple remote MEPs or multiple sessions to the same remote MEP."; } leaf ttl { config true; type uint8; default "255"; } leaf interval { type Interval; Senevirathne Expires April 25, 2015 [Page 26] Internet-Draft YANG Data Model for Generic OAM October 2014 description "Transmission interval for CC packets for this session."; } leaf enable { default "false"; config true; type boolean; description "enable or disable a monitor session"; } leaf ecmp-choice { config true; type ecmp-choices; description "0 means use the specified interface 1 means use round robin"; } leaf source-mep { type MEP-name; description "Source MEP for this session, if applicable"; } container destination-mep { uses MEP-ID; } container destination-mep-address { uses mp-address; } uses connectivity-context; uses flow-entropy; uses priority; list outgoing-interface { key "interface"; config true; leaf interface { type leafref { path "/if:interfaces/if:interface/if:name"; } config true; } } } } list MIP { key "interface"; uses MIP; Senevirathne Expires April 25, 2015 [Page 27] Internet-Draft YANG Data Model for Generic OAM October 2014 } list related-oam-layer { key "offset"; description "List of OAM layers above and below that are related to current MA. This allow users to easily navigate up and down to efficiently troubleshoot a connectivity issue"; uses related-oam-layer; } } } } } notification RDI-notification { description "When RDI is received this notificiation is sent"; uses ma-identifier; leaf mep-name { type MEP-name; description "Indicate which MEP is seeing the error"; } container remote-mepid { uses MEP-ID; description "Who is seeing the error (if known) if unknown make it 0."; } leaf error-message { type string { length "0..255"; } description "Error message to indicate more details."; } } rpc ping { description "Generates Ping and return response"; input { uses ma-identifier { description "identfies the Maintenance association"; } uses flow-entropy; uses priority; leaf ttl { Senevirathne Expires April 25, 2015 [Page 28] Internet-Draft YANG Data Model for Generic OAM October 2014 type uint8; default "255"; } leaf ecmp-choice { type ecmp-choices; description "0 means use the specified interface 1 means use round robin"; } leaf sub-type { type identityref { base command-sub-type; } description "defines different command types"; } list outgoing-interfaces { key "interface"; leaf interface { type if:interface-ref; } } leaf source-mep { type MEP-name; } container destination-mp { uses mp-address; uses MEP-ID { description "Only applicable if the destination is a MEP"; } } leaf count { type uint32; default "3"; description "Number of ping echo request message to send"; } leaf interval { type Interval; description "Interval between echo requests"; } leaf packet-size { type uint32 { range "64..10000"; } default "64"; Senevirathne Expires April 25, 2015 [Page 29] Internet-Draft YANG Data Model for Generic OAM October 2014 description "Size of ping echo request packets, in octets"; } } output { uses monitor-stats { description "Stats of Ping is same as that of monitor sessions"; } } } rpc trace-route { description "Generates Trace-route and return response. Starts with TTL of one and increment by one at each hop. Untill destination reached or TTL reach max valune"; input { uses ma-identifier { description "identfies the Maintenance association"; } uses flow-entropy; uses priority; leaf ttl { type uint8; default "255"; } leaf command-sub-type { type identityref { base command-sub-type; } description "defines different command types"; } leaf ecmp-choice { type ecmp-choices; description "0 means use the specified interface 1 means use round robin"; } list outgoing-interfaces { key "interface"; leaf interface { type if:interface-ref; } } leaf source-mep { Senevirathne Expires April 25, 2015 [Page 30] Internet-Draft YANG Data Model for Generic OAM October 2014 type MEP-name; } container destination-mp { uses mp-address; uses MEP-ID { description "Only applicable if the destination is a 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 send at each TTL."; } leaf interval { type Interval; description "Interval between echo requests"; } } output { list response { key "response-index"; leaf response-index { description "Arbitrary index for the response. In protocols that guarantee there is only a single response at each TTL (eg IP Traceroute), the TTL can be used as the response index."; type uint8; } leaf ttl { type uint8; } container destination-mp { description "MP from which the response has been received"; uses mp-address; uses MEP-ID { description "Only applicable if the destination is a MEP"; } } uses monitor-stats { description "If count is 1, there is a single delay value reported."; Senevirathne Expires April 25, 2015 [Page 31] Internet-Draft YANG Data Model for Generic OAM October 2014 } } } } } Figure 6 YANG module of OAM 7. Base Mode for IP The Base Mode 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. 7.1. MEP Address In the Base Mode of operation, the MEP Address is the IP address of the interface on which the MEP is located. 7.2. MEP ID for Base Mode In the Base Mode of operation, each device creates a single UP MEP associated with a virtual OAM port with no physical layer (NULL PHY). The MEPID associated with this MEP is zero (0). The choice of MEP-ID zero is explained below. MEPID is 2 octet field. It is never used on the wire except when using CCM. Ping, traceroute and session monitoring does not use the MEPID on its message header. 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 IP we propose to use MEP ID zero (0) as the default MEP-ID. CCM packet use MEP-ID on the paylod. CCM MUST NOT be used in the Base Mode for IP. 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. [8021Q] CFM defines MEP ID as an unsigned integer in the range 1 to 8191. In this document we propose to extend the range to 0 to 65535. Value 0 is reserved for MEP ID of Base Mode of IP and MUST NOT be used for other purposes. Senevirathne Expires April 25, 2015 [Page 32] Internet-Draft YANG Data Model for Generic OAM October 2014 7.3. Maintenance Domain Default MD-LEVEL is set to 3. 7.4. Maintenance Association MAID [8021Q] has a flexible format and includes two parts: Maintenance Domain Name and Short MA name. In the Based Mode of operation, the value of the Maintenance Domain Name must be the character string "GenericBaseMode" (excluding the quotes "). In Base Mode operation Short MA Name format is set to 2-octet integer format (value 3 in Short MA Format field [8021Q]) and Short MA name set to 65532 (0xFFFC). 8. Security Considerations TBD 9. IANA Considerations This document registers the following namespace URI in the IETF XML registry. URI:TBD 10. References 10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC792] Postel, J., "Internet Control Message Protocol", STD 5,RFC 792, September 1981. [8021Q] IEEE, "Media Access Control (MAC) Bridges and Virtual Bridged Local Area Networks", IEEE Std 802.1Q-2011, August, 2011. 10.2. Informative References [Y1731] ITU, "OAM functions and mechanisms for Ethernet based networks", ITU-T G.8013/Y.1731, July, 2011. Senevirathne Expires April 25, 2015 [Page 33] Internet-Draft YANG Data Model for Generic OAM October 2014 [RFC7174] Salam, S., et.al., "TRILL OAM Framework", RFC7174, May 2014. [RFC6291] Andersson, L., et.al., "Guidelines for the use of the "OAM" Acronym in the IETF" RFC 6291, June 2011. [RFC6325] Perlman, R., et.al., "Routing Bridges (RBridges): Base Protocol Specification", RFC 6325, July 2011. [OAMOVW] Mizrahi, T., et.al., "An Overview of Operations, Administration, and Maintenance (OAM) Tools", draft-ietf- opsawg-oam-overview-16, Work in Progress, March 2014. [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", RFC 4443, March 2006. [RFC4379] Kompella, K. and G. Swallow, "Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures", RFC 4379, February 2006. [RFC6371] Busi, I., et.al., "Operations, Administration, and Maintenance Framework for MPLS-Based Transport Networks, RFC 6317, September 2011. [TRILLOAMFM] Senevirathne, T., et.al., "TRILL OAM Fault Management", draft-ietf-trill-oam-fm, Work in Progress, May 2014. 11. Acknowledgments 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 and others participated and contributed to this document. This document was prepared using 2-Word-v2.0.template.dot. Senevirathne Expires April 25, 2015 [Page 34] Internet-Draft YANG Data Model for Generic OAM October 2014 12. Contributors Tissa Senevirathne, Norman Finn, Samer Salam, Deepak Kumar, Qin Wu, David Ball. Authors' Addresses Tissa Senevirathne CISCO Systems 375 East Tasman Drive. San Jose, CA 95134 USA. Phone: 408-853-2291 Email: tsenevir@cisco.com Norman Finn CISCO Systems 510 McCarthy Blvd Milpitas, CA 95035. Email: nfinn@cisco.com Deepak Kumar CISCO Systems 510 McCarthy Blvd Milpitas, CA 95035. Email: dekumar@cisco.com Samer Salam CISCO Systems 595 Burrard St. Suite 2123 Vancouver, BC V7X 1J1, Canada Email: ssalam@cisco.com Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 Email: bill.wu@huawei.com Senevirathne Expires April 25, 2015 [Page 35] Internet-Draft YANG Data Model for Generic OAM October 2014 Senevirathne Expires April 25, 2015 [Page 36]