| Internet-Draft | YANG Model for IOAM | January 2022 |
| Zhou, Ed., et al. | Expires 18 July 2022 | [Page] |
In-situ Operations, Administration, and Maintenance (IOAM) records operational and telemetry information in user packets while the packets traverse a path between two points in the network. This document defines a YANG module for the IOAM function.¶
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 18 July 2022.¶
Copyright (c) 2022 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶
In-situ Operations, Administration, and Maintenance (IOAM) [I-D.ietf-ippm-ioam-data] records OAM information within user packets while the packets traverse a network. The data types and data formats for IOAM data records have been defined in [I-D.ietf-ippm-ioam-data]. The IOAM data can be embedded in many protocol encapsulations such as Network Services Header (NSH) and IPv6.¶
This document defines a data model for IOAM capabilities using the YANG data modeling language [RFC7950]. This YANG model supports five IOAM options, which are Incremental Tracing Option, Pre-allocated Tracing Option, Direct Export Option[I-D.ietf-ippm-ioam-direct-export], Proof of Transit (PoT) Option, and Edge-to-Edge Option.¶
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP14, [RFC2119], [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
The following terms are defined in [RFC7950] and are used in this specification:¶
The terminology for describing YANG data models is found in [RFC7950].¶
Tree diagrams used in this document follow the notation defined in [RFC8340].¶
The IOAM model is organized as list of profiles as shown in the following figure. Each profile associates with one flow and the corresponding IOAM information.¶
The "ioam-info" is a container for all the read only assistant information, so that monitoring systems can interpret the IOAM data.¶
module: ietf-ioam
+--rw ioam
+--ro ioam-info
| +--ro timestamp-type? identityref
| +--ro available-interface* [if-name]
| +--ro if-name -> if:interfaces/interface/name
+--rw ioam-profiles
+--rw admin-config
| +--rw enabled? boolean
+--rw ioam-profile* [profile-name]
+--rw profile-name string
+--rw filter
| +--rw filter-type? ioam-filter-type
| +--rw ace-name? -> /acl:acls/acl/aces/ace/name
+--rw protocol-type? ioam-protocol-type
+--rw incremental-tracing-profile {incremental-trace}?
| ...
+--rw preallocated-tracing-profile {preallocated-trace}?
| ...
+--rw direct-export-profile {direct-export}?
| ...
+--rw pot-profile {proof-of-transit}?
| ...
+--rw e2e-profile {edge-to-edge}?
...¶
In the "ioam-profiles", the "enabled" is an administrative configuration. When it is set to true, IOAM configuration is enabled for the system. Meanwhile, the IOAM data-plane functionality is enabled.¶
The "filter" is used to identify a flow, where the IOAM profile can apply. There may be multiple filter types. ACL [RFC8519] is a common way to specify a flow. Each IOAM profile can associate with an ACE(Access Control Entry). IOAM actions MUST be driven by the accepted packets, when the matched ACE "forwarding" action is "accept".¶
The IOAM data can be encapsulated into multiple protocols, e.g., IPv6 [I-D.ietf-ippm-ioam-ipv6-options] and NSH [I-D.ietf-sfc-ioam-nsh]. The "protocol-type" is used to indicate where the IOAM is applied. For example, if the "protocol-type" is IPv6, the IOAM ingress node will encapsulate the associated flow with the IPv6-IOAM [I-D.ietf-ippm-ioam-ipv6-options] format.¶
IOAM data includes five encapsulation types, i.e., incremental tracing data, preallocated tracing data, direct export data, prove of transit data and end to end data. In practice, multiple IOAM data types can be encapsulated into the same IOAM header. The "ioam-profile" contains a set of sub-profiles, each of which relates to one encapsulation type. The configured object may not support all the sub-profiles. The supported sub-profiles are indicated by 5 defined features, i.e., "incremental-trace", "preallocated-trace", "direct export", "proof-of-transit", "edge-to-edge".¶
The IOAM tracing data is expected to be collected at every node that a packet traverses to ensure visibility into the entire path a packet takes within an IOAM domain. The preallocated tracing option will create pre-allocated space for each node to populate its information . The "preallocated-tracing-profile" contains the detailed information for the preallocated tracing data. The information includes:¶
+--rw preallocated-tracing-profile {preallocated-trace}?
+--rw enabled? boolean
+--rw node-action? ioam-node-action
+--rw trace-types
| +--rw use-namespace? ioam-namespace
| +--rw trace-type* ioam-trace-type
+--rw enable-loopback-mode? boolean
+--rw enable-active-mode? boolean¶
The incremental tracing option contains a variable node data fields where each node allocates and pushes its node data immediately following the option header. The "incremental-tracing-profile" contains the detailed information for the incremental tracing data. The detailed information is the same as the Preallocated Tracing Profile, but with one more variable, "max-length", which restricts the length of the IOAM header.¶
+--rw incremental-tracing-profile {incremental-trace}?
+--rw enabled? boolean
+--rw node-action? ioam-node-action
+--rw trace-types
| +--rw use-namespace? ioam-namespace
| +--rw trace-type* ioam-trace-type
+--rw enable-loopback-mode? boolean
+--rw enable-active-mode? boolean
+--rw max-length? uint32¶
The direct export option is used as a trigger for IOAM nodes to export IOAM data to a receiving entity (or entities). The "direct-export-profile" contains the detailed information for the direct export data. The detailed information is the same as the Preallocated Tracing Profile, but with one more optional variable, "flow-id", which is used to correlate the exported data of the same flow from multiple nodes and from multiple packets.¶
+--rw direct-export-profile {direct-export}?
+--rw enabled? boolean
+--rw node-action? ioam-node-action
+--rw trace-types
| +--rw use-namespace? ioam-namespace
| +--rw trace-type* ioam-trace-type
+--rw enable-loopback-mode? boolean
+--rw enable-active-mode? boolean
+--rw flow-id? uint32¶
The IOAM Proof of Transit data is to support the path or service function chain verification use cases. The "pot-profile" contains the detailed information for the proof of transit data. "pot-type" indicates a particular POT variant that specifies the POT data that is included. There may be several POT types, which have different configuration data. To align with [I-D.ietf-ippm-ioam-data], this document only defines IOAM POT type 0. User need to augment this module for the configuration of a specifc POT type.¶
+--rw pot-profile {proof-of-transit}?
+--rw enabled? boolean
+--rw pot-type? ioam-pot-type¶
The IOAM edge to edge option is to carry data that is added by the IOAM encapsulating node and interpreted by IOAM decapsulating node. The "e2e-profile" contains the detailed information for the edge to edge data. The detailed information includes:¶
+--rw e2e-profile {edge-to-edge}?
+--rw enabled? boolean
+--rw node-action? ioam-node-action
+--rw e2e-types
+--rw use-namespace? ioam-namespace
+--rw e2e-type* ioam-e2e-type¶
<CODE BEGINS> file "ietf-ioam@2021-01-12.yang"
module ietf-ioam {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-ioam";
prefix "ioam";
import ietf-access-control-list {
prefix "acl";
reference
"RFC 8519: YANG Data Model for Network Access Control
Lists (ACLs)";
}
import ietf-interfaces {
prefix "if";
reference
"RFC 8343: A YANG Data Model for Interface Management";
}
import ietf-lime-time-types {
prefix "lime";
reference
"RFC RFC 8532: Generic YANG Data Model for the Management of
Operations, Administration, and Maintenance (OAM) Protocols
That Use Connectionless Communications";
}
organization
"IETF IPPM (IP Performance Metrics) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/ippm>
WG List: <ippm@ietf.org>
Editor: zhoutianran@huawei.com
Editor: james.n.guichard@futurewei.com
Editor: fbrockne@cisco.com
Editor: srihari@cisco.com";
description
"This YANG module specifies a vendor-independent data
model for the In Situ OAM (IOAM).
Copyright (c) 2021 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see the
RFC itself for full legal notices.";
revision 2022-01-12 {
description "Firstd revision.";
reference "draft-ietf-ippm-ioam-yang";
}
/*
* FEATURES
*/
feature incremental-trace
{
description
"This feature indicated that the incremental tracing option is
supported";
reference "draft-ietf-ippm-ioam-data";
}
feature preallocated-trace
{
description
"This feature indicated that the preallocated tracing option is
supported";
reference "draft-ietf-ippm-ioam-data";
}
feature direct-export
{
description
"This feature indicated that the direct export option is
supported";
reference "ietf-ippm-ioam-direct-export";
}
feature proof-of-transit
{
description
"This feature indicated that the proof of transit option is
supported";
reference "draft-ietf-ippm-ioam-data";
}
feature edge-to-edge
{
description
"This feature indicated that the edge to edge option is
supported";
reference "draft-ietf-ippm-ioam-data";
}
/*
* IDENTITIES
*/
identity base-filter {
description
"Base identity to represent a filter. A filter is used to
specify the flow to apply the IOAM profile. ";
}
identity acl-filter {
base base-filter;
description
"Apply ACL rules to specify the flow.";
}
identity base-protocol {
description
"Base identity to represent the carrier protocol. It's used to
indicate what layer and protocol the IOAM data is embedded.";
}
identity ipv6-protocol {
base base-protocol;
description
"The described IOAM data is embedded in IPv6 protocol.";
reference "ietf-ippm-ioam-ipv6-options";
}
identity nsh-protocol {
base base-protocol;
description
"The described IOAM data is embedded in NSH.";
reference "ietf-sfc-ioam-nsh";
}
identity base-node-action {
description
"Base identity to represent the node actions. It's used to
indicate what action the node will take.";
}
identity action-encapsulate {
base base-node-action;
description
"indicate the node is to encapsulate the IOAM packet";
}
identity action-decapsulate {
base base-node-action;
description
"indicate the node is to decapsulate the IOAM packet";
}
identity base-trace-type {
description
"Base identity to represent trace types";
}
identity trace-hop-lim-node-id {
base base-trace-type;
description
"indicates presence of Hop_Lim and node_id in the
node data.";
}
identity trace-if-id {
base base-trace-type;
description
"indicates presence of ingress_if_id and egress_if_id in the
node data.";
}
identity trace-timestamp-seconds {
base base-trace-type;
description
"indicates presence of time stamp seconds in the node data.";
}
identity trace-timestamp-nanoseconds {
base base-trace-type;
description
"indicates presence of time stamp nanoseconds in the node data.";
}
identity trace-transit-delay {
base base-trace-type;
description
"indicates presence of transit delay in the node data.";
}
identity trace-namespace-data {
base base-trace-type;
description
"indicates presence of namespace specific data (short format)
in the node data.";
}
identity trace-queue-depth {
base base-trace-type;
description
"indicates presence of queue depth in the node data.";
}
identity trace-opaque-state-snapshot {
base base-trace-type;
description
"indicates presence of variable length Opaque State Snapshot
field.";
}
identity trace-hop-lim-node-id-wide {
base base-trace-type;
description
"indicates presence of Hop_Lim and node_id wide in the
node data.";
}
identity trace-if-id-wide {
base base-trace-type;
description
"indicates presence of ingress_if_id and egress_if_id wide in
the node data.";
}
identity trace-namespace-data-wide {
base base-trace-type;
description
"indicates presence of namespace specific data in wide format
in the node data.";
}
identity trace-buffer-occupancy {
base base-trace-type;
description
"indicates presence of buffer occupancy in the node data.";
}
identity trace-checksum-complement {
base base-trace-type;
description
"indicates presence of the Checksum Complement node data.";
}
identity base-pot-type {
description
"Base identity to represent Proof of Transit(PoT) types";
}
identity pot-type-0 {
base base-pot-type;
description
"POT data is a 16 Octet field to carry data associated to
POT procedures.";
}
identity base-e2e-type {
description
"Base identity to represent e2e types";
}
identity e2e-seq-num-64 {
base base-e2e-type;
description
"indicates presence of a 64-bit sequence number";
}
identity e2e-seq-num-32 {
base base-e2e-type;
description
"indicates presence of a 32-bit sequence number";
}
identity e2e-timestamp-seconds {
base base-e2e-type;
description
"indicates presence of timestamp seconds for the
transmission of the frame";
}
identity e2e-timestamp-subseconds {
base base-e2e-type;
description
"indicates presence of timestamp subseconds for the
transmission of the frame";
}
identity base-namespace {
description
"Base identity to represent the namespace";
}
identity namespace-ietf {
base base-namespace;
description
"namespace that specified in IETF.";
}
/*
* TYPE DEFINITIONS
*/
typedef ioam-filter-type {
type identityref {
base base-filter;
}
description
"Specifies a known type of filter.";
}
typedef ioam-protocol-type {
type identityref {
base base-protocol;
}
description
"Specifies a known type of carrier protocol for the IOAM data.";
}
typedef ioam-node-action {
type identityref {
base base-node-action;
}
description
"Specifies a known type of node action.";
}
typedef ioam-trace-type {
type identityref {
base base-trace-type;
}
description
"Specifies a known trace type.";
}
typedef ioam-pot-type {
type identityref {
base base-pot-type;
}
description
"Specifies a known pot type.";
}
typedef ioam-e2e-type {
type identityref {
base base-e2e-type;
}
description
"Specifies a known e2e type.";
}
typedef ioam-namespace {
type identityref {
base base-namespace;
}
description
"Specifies the supported namespace.";
}
/*
* GROUP DEFINITIONS
*/
grouping ioam-filter {
description "A grouping for IOAM filter definition";
leaf filter-type {
type ioam-filter-type;
description "filter type";
}
leaf ace-name {
when "../filter-type = 'ioam:acl-filter'";
type leafref {
path "/acl:acls/acl:acl/acl:aces/acl:ace/acl:name";
}
description "Access Control Entry name.";
}
}
grouping encap-tracing {
description
"A grouping for the generic configuration for
tracing profile.";
container trace-types {
description
"the list of trace types for encapsulate";
leaf use-namespace {
type ioam-namespace;
description
"the namespace used for the encapsulation";
}
leaf-list trace-type {
type ioam-trace-type;
description
"The trace type is only defined at the encapsulation node.";
}
}
leaf enable-loopback-mode {
type boolean;
default false;
description
"Loopback mode is used to send a copy of a packet back towards
the source. The loopback mode is only defined at the
encapsulation node.";
}
leaf enable-active-mode {
type boolean;
default false;
description
"Active mode indicates that a packet is used for active
measurement. An IOAM decapsulating node that receives a
packet with the Active flag set in one of its Trace options
must terminate the packet.";
}
}
grouping ioam-incremental-tracing-profile {
description
"A grouping for incremental tracing profile.";
leaf node-action {
type ioam-node-action;
description "node action";
}
uses encap-tracing {
when "node-action = 'ioam:action-encapsulate'";
}
leaf max-length {
when "../node-action = 'ioam:action-encapsulate'";
type uint32;
units bytes;
description
"This field specifies the maximum length of the node data list
in octets. The max-length is only defined at the
encapsulation node. And it's only used for the incremental
tracing mode.";
}
}
grouping ioam-preallocated-tracing-profile {
description
"A grouping for incremental tracing profile.";
leaf node-action {
type ioam-node-action;
description "node action";
}
uses encap-tracing {
when "node-action = 'ioam:action-encapsulate'";
}
}
grouping ioam-direct-export-profile {
description
"A grouping for direct export profile.";
leaf node-action {
type ioam-node-action;
description "node action";
}
uses encap-tracing {
when "node-action = 'ioam:action-encapsulate'";
}
leaf flow-id {
when "../node-action = 'ioam:action-encapsulate'";
type uint32;
description
"A 32-bit flow identifier. The field is set at the
encapsulating node. The Flow ID can be uniformly assigned
by a central controller or algorithmically generated by the
encapsulating node. The latter approach cannot guarantee
the uniqueness of Flow ID, yet the conflict probability is
small due to the large Flow ID space.flow-id is used to
correlate the exported data of the same flow from multiple
nodes and from multiple packets.";
}
}
grouping ioam-e2e-profile {
description
"A grouping for end to end profile.";
leaf node-action {
type ioam-node-action;
description
"indicate how the node act for this profile";
}
container e2e-types {
when "../node-action = 'ioam:action-encapsulate'";
description
"the list of e2e types for encapsulate";
leaf use-namespace {
type ioam-namespace;
description
"the namespace used for the encapsulation";
}
leaf-list e2e-type {
type ioam-e2e-type;
description
"The e2e type is only defined at the encapsulation node.";
}
}
}
grouping ioam-admin-config {
description
"IOAM top-level administrative configuration.";
leaf enabled {
type boolean;
default false;
description
"When true, IOAM configuration is enabled for the system.
Meanwhile, the IOAM data-plane functionality is enabled.";
}
}
/*
* DATA NODES
*/
container ioam {
description "IOAM top level container";
container ioam-info {
config false;
description
"Describes assistant information such as units or timestamp
format. So that monitoring systems can interpret the IOAM
data.";
leaf timestamp-type {
type identityref {
base lime:timestamp-type;
}
description
"Type of timestamp, such as Truncated PTP or NTP.";
}
list available-interface {
key "if-name";
ordered-by user;
description
"A list of available interfaces that support IOAM.";
leaf if-name {
type leafref {
path "/if:interfaces/if:interface/if:name";
}
description "Interface name.";
}
}
}
container ioam-profiles {
description
"Contains a list of IOAM profiles.";
container admin-config {
description
"Contains all the administrative configurations related to
the IOAM functionalities and all the IOAM profiles.";
uses ioam-admin-config;
}
list ioam-profile {
key "profile-name";
ordered-by user;
description
"A list of IOAM profiles that configured on the node.";
leaf profile-name {
type string;
mandatory true;
description
"Unique identifier for each IOAM profile";
}
container filter {
uses ioam-filter;
description
"The filter which is used to indicate the flow to apply
IOAM.";
}
leaf protocol-type {
type ioam-protocol-type;
description
"This item is used to indicate the carrier protocol where
the IOAM is applied.";
}
container incremental-tracing-profile {
if-feature incremental-trace;
description
"describe the profile for incremental tracing option";
leaf enabled {
type boolean;
default false;
description
"When true, apply incremental tracing option to the
specified flow identified by the filter.";
}
uses ioam-incremental-tracing-profile;
}
container preallocated-tracing-profile {
if-feature preallocated-trace;
description
"describe the profile for preallocated tracing option";
leaf enabled {
type boolean;
default false;
description
"When true, apply preallocated tracing option to the
specified flow identified by the following filter.";
}
uses ioam-preallocated-tracing-profile;
}
container direct-export-profile {
if-feature direct-export;
description
"describe the profile for direct-export option";
leaf enabled {
type boolean;
default false;
description
"When true, apply direct-export option to the
specified flow identified by the following filter.";
}
uses ioam-direct-export-profile;
}
container pot-profile {
if-feature proof-of-transit;
description
"describe the profile for PoT option";
leaf enabled {
type boolean;
default false;
description
"When true, apply Proof of Transit option to the
specified flow identified by the following filter.";
}
leaf pot-type {
type ioam-pot-type;
description
"The type of a particular POT variant that specifies
the POT data that is included..";
}
}
container e2e-profile {
if-feature edge-to-edge;
description
"describe the profile for e2e option";
leaf enabled {
type boolean;
default false;
description
"When true, apply End to end option to the
specified flow identified by the following filter.";
}
uses ioam-e2e-profile;
}
}
}
}
}
<CODE ENDS>¶
The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC5246].¶
The NETCONF access control model [RFC6536] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content.¶
There are a number of data nodes defined in this YANG module that 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. These are the subtrees and data nodes and their sensitivity/vulnerability:¶
The items in the container above include the top level administrative configurations related to the IOAM functionalities and all the IOAM profiles. Unexpected changes to these items could lead to the IOAM function disruption and/ or misbehavior of all the IOAM profiles.¶
The entries in the list above include the whole IOAM profile configurations which indirectly create or modify the device configurations. Unexpected changes to these entries could lead to the mistake of the IOAM behavior for the corresponding flows.¶
RFC Ed.: In this section, replace all occurrences of 'XXXX' with the actual RFC number (and remove this note).¶
IANA is requested to assign a new URI from the IETF XML Registry [RFC3688]. The following URI is suggested:¶
URI: urn:ietf:params:xml:ns:yang:ietf-ioam
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.¶
This document also requests a new YANG module name in the YANG Module Names registry [RFC7950] with the following suggestion:¶
name: ietf-ioam
namespace: urn:ietf:params:xml:ns:yang:ietf-ioam
prefix: ioam
reference: RFC XXXX¶
For their valuable comments, discussions, and feedback, we wish to acknowledge Greg Mirsky, Reshad Rahman, Tom Petch and Mickey Spiegel.¶
This appendix is non-normative.¶
tbd¶