| Network Working Group | D. Kumar |
| Internet-Draft | Cisco |
| Intended status: Standards Track | Q. Wu |
| Expires: June 21, 2018 | M. Wang |
| Huawei | |
| December 18, 2017 |
Generic YANG Data Model for Connection Oriented Operations, Administration, and Maintenance(OAM) protocols
draft-ietf-lime-yang-connection-oriented-oam-model-02
This document presents a base YANG Data model for connection oriented 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)
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). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.
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."
This Internet-Draft will expire on June 21, 2018.
Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
Operations, Administration, and Maintenance (OAM) are important networking functions that allow operators to:
An overview of OAM tools is presented in [RFC7276]. Over the years, many technologies have developed similar tools for fault and performance management.
[IEEE802.1ag] Connectivity Fault Management is a well-established OAM standard that is widely adopted for Ethernet networks. ITU-T [G.8013], MEF Service OAM, MPLS-TP [RFC6371], TRILL [RFC7455] all define OAM mechanisms based on the manageability frame work of CFM [IEEE802.1ag].
Given the wide adoption of the underlying OAM concepts defined in CFM [IEEE802.1ag], 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 [IEEE802.1ag] 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).
All implementations that follow the YANG framework presented in this document MUST implement the generic connection oriented YANG model presented here.
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 Loopback from device A 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 [IEEE802.1ag]. Upon detecting the Loopback failures, a user 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 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 [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 [RFC2119] significance.
The following notations are used within the data tree and carry the meaning as below.
<status> <flags> <name> <opts> <type>
<status> is one of:
+ for current
<flags> is one of:
rw for configuration data
ro for non-configuration data
-x for rpcs
-n for notifications
-w for writable
<name> is the name of the node
Each node is printed as:
<opts> is one of:
? for an optional leaf or choice
! for a presence container
* for a leaf-list or list
[<keys>] for a list's keys
(choice)/:(case) Parentheses enclose choice and case nodes,
and case nodes are also marked with a colon (":")
<type> is the name of the type for leafs and leaf-lists
If the node is augmented into the tree from another module, its name is printed as <prefix>:<name>.
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 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 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.
Figure 1 depicts relationship of different YANG modules.
+----------+
|Connection|
| Oriented |
| gen |
|OAM YANG |
+-+-+-+-+-++
|
|
|
+------------------------------------------+
| | |
+-+-+-+-+-+ +-+-+-+-+-+ +-+-+-+-+-+
| TRILL | | MPLS-TP | . . .| foo |
|OAM YANG | |OAM YANG | |OAM YANG |
+-+-+-+-+-+ +-+-+-+-+-+ +-+-+-+-+-+
| | |
| | +-+-+-+-+-+
| | . . .| foo |
| | |sub tech |
| | +-+-+-+-+-+
| | |
| | |
+-------------------------------------------------------+
| Uniform API |
+-------------------------------------------------------+
Relationship of OAM YANG model to generic (base) YANG model
In this document we adopt the concepts of the CFM [IEEE802.1ag] 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 Association (MA). In TRILL this can be per Fine-Grained Label or for VPLS this can be per VPLS instance [RFC6136].
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 vertical 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 OAM toolset specified in section 5.1 of [RFC7276]. 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 [RFC7455]. 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", 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 [IEEE802.1ag] 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.
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
Snippet of data hierarchy related to OAM domains
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
Snippet of data hierarchy related to Maintenance Associations (MA)
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: ietf-connection-oriented-oam
+--rw domains
+--rw domain* [technology md-name-string]
+--rw technology identityref
.
.
+--rw mas
+--rw ma* [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 (mep-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
. .
. .
. .
Snippet of data hierarchy related to Maintenance Endpoint (MEP)
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 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
| | | | +--:(ipv4-address)
| | | | | +---w ipv4-address? inet:ipv4-address
| | | | +--:(ipv6-address)
| | | | +---w ipv6-address? inet:ipv6-address
| | | +---w (mep-id)?
| | | | +--:(mep-id-int)
| | | | +---w mep-id-int? int32
| | | +---w mep-id-format? identityref
| | +---w count? uint32
| | +---w cc-transmit-interval? 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
| | | | +--:(ipv4-address)
| | | | | +---w ipv4-address? inet:ipv4-address
| | | | +--:(ipv6-address)
| | | | +---w ipv6-address? inet:ipv6-address
| | | +---w (mep-id)?
| | | | +--:(mep-id-int)
| | | | +---w mep-id-int? int32
| | | +---w mep-id-format? identityref
| | +---w count? uint32
| | +---w interval? 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
| | | +--:(ipv4-address)
| | | | +---w ipv4-address? inet:ipv4-address
| | | +--:(ipv6-address)
| | | +---w ipv6-address? inet:ipv6-address
| | +---w (mep-id)?
| | | +--:(mep-id-int)
| | | +---w mep-id-int? int32
| | +---w mep-id-format? identityref
| +---w count? uint32
| +---w interval? 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
| | +--:(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 mip {mip}?
| +--ro interface? if:interface-ref
| +--ro (mip-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 (monitor-stats)?
+--:(monitor-null)
+--ro monitor-null? empty
Snippet of data hierarchy related to RPC call continuity-check
Notification is sent on defect condition and defect clears 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 Yang modules which Augment Yang 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
| | +--:(ipv4-address)
| | | +--rw ipv4-address? inet:ipv4-address
| | +--:(ipv6-address)
| | +--rw ipv6-address? inet:ipv6-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
| | +--:(ipv4-address)
| | | +--rw ipv4-address? inet:ipv4-address
| | +--:(ipv6-address)
| | +--rw ipv6-address? inet:ipv6-address
| +--rw cos-id? uint8
+--rw mip* [interface] {mip}?
+--rw interface if:interface-ref
+--rw (mip-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
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
| | | | +--:(ipv4-address)
| | | | | +---w ipv4-address? inet:ipv4-address
| | | | +--:(ipv6-address)
| | | | +---w ipv6-address? inet:ipv6-address
| | | +---w (mep-id)?
| | | | +--:(mep-id-int)
| | | | +---w mep-id-int? int32
| | | +---w mep-id-format? identityref
| | +---w count? uint32
| | +---w cc-transmit-interval? 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
| | | | +--:(ipv4-address)
| | | | | +---w ipv4-address? inet:ipv4-address
| | | | +--:(ipv6-address)
| | | | +---w ipv6-address? inet:ipv6-address
| | | +---w (mep-id)?
| | | | +--:(mep-id-int)
| | | | +---w mep-id-int? int32
| | | +---w mep-id-format? identityref
| | +---w count? uint32
| | +---w interval? 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
| | | +--:(ipv4-address)
| | | | +---w ipv4-address? inet:ipv4-address
| | | +--:(ipv6-address)
| | | +---w ipv6-address? inet:ipv6-address
| | +---w (mep-id)?
| | | +--:(mep-id-int)
| | | +---w mep-id-int? int32
| | +---w mep-id-format? identityref
| +---w count? uint32
| +---w interval? 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
| | +--:(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 mip {mip}?
| +--ro interface? if:interface-ref
| +--ro (mip-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 (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
data hierarchy of OAM
<CODE BEGINS> file "ietf-connection-oriented-oam@2017-12-19.yang"
module ietf-connection-oriented-oam {
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
WG Chair: Carlos Pignataro cpignata@cisco.com
WG Chair: Ron Bonica rbonica@juniper.net
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 indpendent manner.
Functional level abstraction is indendent
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";
revision 2017-12-19 {
description
"Initial revision. - 10 version";
reference "draft-ietf-lime-yang-oam-model";
}
/* features */
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";
}
/* Identities */
identity technology-types {
description
"This is the base identy of technology types which are
TRILL,MPLS-TP,vpls etc";
}
identity command-sub-type {
description
"Defines different rpc command subtypes,
e.g rfc6905 trill OAM, this is optional for most cases";
}
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.";
}
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.";
}
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
"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
"If 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) are received within the interval.";
}
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). [RFC6371] highlights,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.";
}
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.";
}
/* typedefs */
typedef mep-name {
type string;
description
"Generic administrative name for a Maintenance End Point
(MEP).";
}
typedef interval{
type decimal64{
fraction-digits 2;
}
units "milliseconds";
description
"Interval between packets in milliseconds.
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 an
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).";
}
/* groupings */
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 {
case mac-address {
leaf mac-address {
type yang:mac-address;
description
"MAC Address";
}
description
"MAC Address based Maintenance End Point (MEP) Addressing.";
}
case ipv4-address {
leaf ipv4-address {
type inet:ipv4-address;
description
"IPv4 Address";
}
description
"IP Address based Maintenance End Point(MEP) Addressing.";
}
case ipv6-address {
leaf ipv6-address {
type inet:ipv6-address;
description
"IPv6 Address";
}
description
"IPv6 Address based Maintenance End Point(MEP) Addressing.";
}
description
"Maintenance End Point (MEP) Addressing.";
}
description
"Maintenance End Point(MEP) Address";
}
grouping mip-address {
choice mip-address {
case mac-address {
leaf mac-address {
type yang:mac-address;
description
"MAC Address";
}
description
"MAC Address based Maintenance Intermediate
Point (MIP) Addressing.";
}
case ipv4-address {
leaf ipv4-address {
type inet:ipv4-address;
description
"IPv4 Address.";
}
description
"IP Address based Maintenance Intermediate
Point (MIP) Addressing.";
}
case ipv6-address {
leaf ipv6-address {
type inet:ipv6-address;
description
"IPv6 Address.";
}
description
"IPv6 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
"Name format.";
}
choice md-name {
case md-name-null {
leaf md-name-null {
when "../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 "../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, a VRF for VPLS,
or 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
"Priority used in transmitted packets; for example, in the
EXP field in MPLS-TP.";
leaf cos-id {
type uint8;
description
"Class of service.";
}
}
grouping mip-grouping {
uses mip-address;
description
"Grouping for Maintenance Intermediate Point(MIP)
configuration.";
}
container domains {
description
"Contains configuration related data. Within the container
is list of fault domains. Within each domian has List of
Maintenance Association (MA).";
list domain {
key "technology md-name-string";
description
"Define the list of fault 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";
ordered-by user;
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 "interface";
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 interval;
description
"Interval between echo requests.";
}
leaf packet-size {
type uint32 {
range "0..10000";
}
default "64";
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 interval;
description
"Interval between echo requests.";
}
leaf packet-size {
type uint32 {
range "64..10000";
}
default "64";
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 interval;
description
"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 we propose to use MEP-ID zero (0) 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 [IEEE802.1ag] 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) [IEEE802.1ag] 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 [IEEE802.1ag]) and 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 YANG module is augmenting connection oriented OAM module for both configuration and RPC commands.
The TRILL YANG module 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.
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 connection oriented OAM Module with some technology-specific details. And the [mpls-tp-oam-yang] 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 LIME base model as default values. For example domain name can be set to area-ID or the provider's Autonomous System Number(ASN) [RFC6370] 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 Connection Oriented 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 defined in this memo is designed to be accessed via the NETCONF protocol [RFC6241] [RFC6241]. The lowest NETCONF layer is the secure transport layer and the mandatory-to-implement secure transport is SSH [RFC6242] [RFC6242]. The NETCONF access control model [RFC6536] [RFC6536] provides the means to restrict access for particular NETCONF users to a pre-configured subset of all available NETCONF 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 or vulnerable in some network environments. Write operations (e.g., <edit-config>) to these data nodes without proper protection can have a negative effect on network operations.
/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/
The vulnerable "config true" subtrees and data nodes are the following:
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 [RFC3688] [RFC3688]. 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 [RFC6020].
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.
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [RFC3688] | Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004. |
| [RFC6020] | Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010. |
| [RFC6241] | Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011. |
| [RFC6242] | Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011. |
| [RFC6370] | Bocci, M., Swallow, G. and E. Gray, "MPLS Transport Profile (MPLS-TP) Identifiers", RFC 6370, DOI 10.17487/RFC6370, September 2011. |
| [RFC6536] | Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012. |
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