A YANG Data Model for In-Situ
OAMHuawei156 Beiqing Rd.Beijing100095Chinazhoutianran@huawei.comFutureweiUnited States of Americajames.n.guichard@futurewei.comCisco SystemsHansaallee 249, 3rd FloorDuesseldorfNordrhein-Westfalen40549Germanyfbrockne@cisco.comCisco SystemsTril Infopark Sez, Ramanujan IT CityNeville Block, 2nd floor, Old Mahabalipuram RoadChennaiTamil Nadu600113Indiasrihari@cisco.comIPPMIn-situ Operations, Administration, and Maintenance (IOAM) is an
example of an on-path hybrid measurement method. IOAM defines a method
to produce operational and telemetry information that may be exported
using the in-band or out-of-band method. RFC9197 and RFC9326 discuss the
data fields and associated data types for IOAM. This document defines a
YANG module for the configuration of IOAM functions.In-situ Operations, Administration, and Maintenance (IOAM) is an
example of an on-path hybrid measurement method. IOAM defines a method
to produce operational and telemetry information that may be exported
using the in-band or out-of-band method. The data types and data formats
for IOAM data records have been defined in and
. 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 the configuration of IOAM
capabilities using the YANG data modeling
language. This YANG model supports five IOAM options, which
are:Incremental Tracing Option Pre-allocated Tracing OptionDirect Export OptionProof of Transit (PoT) OptionEdge-to-Edge OptionThe keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP14,
, when, and only when,
they appear in all capitals, as shown here.The following terms are defined in and are
used in this specification: augmentdata modeldata nodeThe terminology for describing YANG data models is found in
.Tree diagrams used in this document follow the notation defined in
.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. /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}?
...]]>The "info" is a container for all the read-only information that
assists monitoring systems in the interpretation of the IOAM data.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 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 and 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 format.In this document, IOAM data includes five encapsulation types,
i.e., incremental tracing data, preallocated tracing data, direct
export data, proof of transit data and end to end data. In practice,
multiple IOAM data types can be encapsulated into the same IOAM
header. The "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" and
"edge-to-edge".This document uses the Access Control List
YANG module, the Interfaces YANG
module and the LIME Time Types YANG
module.The YANG data model in this document conform to the Network
Management Datastore Architecture (NMDA) defined in .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:node-action: indicates the operation (e.g., encapsulate IOAM
header, transit the IOAM data, or decapsulate IOAM header) applied
to the dedicated flow.use-namespace: indicates the namespace used for the trace
types.trace-type: indicates the per-hop data to be captured by the
IOAM enabled nodes and included in the node data list.max-length: specifies the maximum length of the node data list
in octets. The max-length is only defined at the encapsulation
node.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.The direct export option is used as a trigger for IOAM data to be
directly exported or locally aggregated without being pushed into
in-flight data packets. 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
two more optional variables:flow-id: is used to correlate the exported data of the same
flow from multiple nodes and from multiple packets.enable-sequence-number: indicates whether the sequence number
is used in the direct export option.The IOAM Proof of Transit data is to support the path or service
function chain verification use cases. The "pot-profile" is intended
to contain the detailed information for the proof of transit data.
"use-namespace" indicates the namespace used for the POT types.
"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 ,
this document only defines IOAM POT type 0. User need to augment this
module for the configuration of a specifc 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:node-action is the same semantic as in Section 3.2.use-namespace: indicate the namespace used for the edge-to-edge
types.e2e-type: indicates data to be carried from the ingress IOAM
node to the egress IOAM node. file "ietf-ioam@2024-03-01.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 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:
WG List:
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).
The key words '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 BCP 14 (RFC 2119) (RFC 8174) when, and only when,
they appear in all capitals, as shown here.
Copyright (c) 2024 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 Revised BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself
for full legal notices.";
revision 2024-03-01 {
description "Initial revision.";
reference "RFC XXXX: A YANG Data Model for In-Situ OAM";
}
/*
* FEATURES
*/
feature incremental-trace
{
description
"This feature indicated that the incremental tracing option is
supported.";
reference "RFC 9197: Data Fields for In-situ OAM";
}
feature preallocated-trace
{
description
"This feature indicated that the preallocated tracing option is
supported.";
reference "RFC 9197: Data Fields for In-situ OAM";
}
feature direct-export
{
description
"This feature indicated that the direct export option is
supported.";
reference "RFC 9326: In-situ OAM Direct Exporting";
}
feature proof-of-transit
{
description
"This feature indicated that the proof of transit option is
supported";
reference "RFC 9197: Data Fields for In-situ OAM";
}
feature edge-to-edge
{
description
"This feature indicated that the edge-to-edge option is
supported.";
reference "RFC 9197: Data Fields for In-situ OAM";
}
/*
* IDENTITIES
*/
identity 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 filter;
description
"Apply ACL rules to specify the flow.";
}
identity 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 {
base protocol;
description
"The described IOAM data is embedded in IPv6 protocol.";
reference
"RFC 9486: In-situ OAM IPv6 Options";
}
identity nsh {
base protocol;
description
"The described IOAM data is embedded in NSH.";
reference
"RFC 9452: Network Service Header (NSH)
Encapsulation for In-situ OAM (IOAM) Data";
}
identity 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 node-action;
description
"It indicates the node is to encapsulate the IOAM packet";
}
identity action-decapsulate {
base node-action;
description
"It indicates the node is to decapsulate the IOAM packet";
}
identity action-transit {
base node-action;
description
"It indicates the node is to transit the IOAM packet";
}
identity trace-type {
description
"Base identity to represent trace types.";
}
identity trace-hop-lim-node-id {
base trace-type;
description
"It indicates the presence of Hop_Lim and node_id in the
node data.";
}
identity trace-if-id {
base trace-type;
description
"It indicates presence of ingress_if_id and egress_if_id
(short format) in the node data.";
}
identity trace-timestamp-seconds {
base trace-type;
description
"It indicates presence of timestamp seconds in the node data.";
}
identity trace-timestamp-fraction {
base trace-type;
description
"It indicates presence of timestamp fraction in the node
data.";
}
identity trace-transit-delay {
base trace-type;
description
"It indicates presence of transit delay in the node data.";
}
identity trace-namespace-data {
base trace-type;
description
"It indicates presence of name space specific data (short
format) in the node data.";
}
identity trace-queue-depth {
base trace-type;
description
"It indicates presence of queue depth in the node data.";
}
identity trace-checksum-complement {
base trace-type;
description
"It indicates presence of the Checksum Complement node data.";
}
identity trace-hop-lim-node-id-wide {
base trace-type;
description
"It indicates presence of Hop_Lim and node_id in wide format
in the node data.";
}
identity trace-if-id-wide {
base trace-type;
description
"It indicates presence of ingress_if_id and egress_if_id in
wide format in the node data.";
}
identity trace-namespace-data-wide {
base trace-type;
description
"It indicates presence of IOAM-Namespace specific data in wide
format in the node data.";
}
identity trace-buffer-occupancy {
base trace-type;
description
"It indicates presence of buffer occupancy in the node data.";
}
identity trace-opaque-state-snapshot {
base trace-type;
description
"It indicates presence of variable length Opaque State Snapshot
field.";
}
identity pot-type {
description
"Base identity to represent Proof of Transit (PoT) types.";
}
identity pot-type-0 {
base pot-type;
description
"The IOAM POT Type field value is 0, and POT data is a 16
Octet field to carry data associated to POT procedures.";
}
identity e2e-type {
description
"Base identity to represent edge-to-edge types.";
}
identity e2e-seq-num-64 {
base e2e-type;
description
"It indicates presence of a 64-bit sequence number.";
}
identity e2e-seq-num-32 {
base e2e-type;
description
"It indicates the presence of a 32-bit sequence number.";
}
identity e2e-timestamp-seconds {
base e2e-type;
description
"It indicates the presence of timestamp seconds representing
the time at which the packet entered the IOAM-domain.";
}
identity e2e-timestamp-fraction {
base e2e-type;
description
"It indicates the presence of timestamp fraction representing
the time at which the packet entered the IOAM-domain.";
}
identity namespace {
description
"Base identity to represent the Namespace-ID.";
}
identity default-namespace {
base namespace;
description
"The Namespace-ID value of 0x0000 is defined as the
Default-Namespace-ID and MUST be known to all the nodes
implementing IOAM.";
}
/*
* TYPE DEFINITIONS
*/
typedef ioam-filter-type {
type identityref {
base filter;
}
description
"It specifies a known type of filter.";
}
typedef ioam-protocol-type {
type identityref {
base protocol;
}
description
"It specifies a known type of carrier protocol for the IOAM
data.";
}
typedef ioam-node-action {
type identityref {
base node-action;
}
description
"It specifies a known type of node action.";
}
typedef ioam-trace-type {
type identityref {
base trace-type;
}
description
"It specifies a known trace type.";
}
typedef ioam-pot-type {
type identityref {
base pot-type;
}
description
"It specifies a known pot type.";
}
typedef ioam-e2e-type {
type identityref {
base e2e-type;
}
description
"It specifies a known edge-to-edge type.";
}
typedef ioam-namespace {
type identityref {
base namespace;
}
description
"It 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 "derived-from-or-self(../filter-type, 'ioam:acl-filter')";
type leafref {
path "/acl:acls/acl:acl/acl:aces/acl:ace/acl:name";
}
description "The Access Control Entry name is used to
refer to an ACL specification.";
}
}
grouping encap-tracing {
description
"A grouping for the generic configuration for
tracing profile.";
container trace-types {
description
"It indicates the list of trace types for encapsulation.";
leaf use-namespace {
type ioam-namespace;
default default-namespace;
description
"It indicates the name space used for encapsulation.";
}
leaf-list trace-type {
type ioam-trace-type;
description
"The trace type is only defined at the encapsulation
node.";
}
}
leaf max-length {
when "derived-from-or-self(../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.";
}
}
grouping ioam-incremental-tracing-profile {
description
"A grouping for incremental tracing profile.";
leaf node-action {
type ioam-node-action;
default action-transit;
description
"This object indicates the action the node need to
take, e.g. encapsulation.";
}
uses encap-tracing {
when "derived-from-or-self(node-action,
'ioam:action-encapsulate')";
}
}
grouping ioam-preallocated-tracing-profile {
description
"A grouping for pre-allocated tracing profile.";
leaf node-action {
type ioam-node-action;
default action-transit;
description
"This object indicates the action the node need to
take, e.g. encapsulation.";
}
uses encap-tracing {
when "derived-from-or-self(node-action,
'ioam:action-encapsulate')";
}
}
grouping ioam-direct-export-profile {
description
"A grouping for direct export profile.";
leaf node-action {
type ioam-node-action;
default action-transit;
description
"This object indicates the action the node need to
take, e.g. encapsulation.";
}
uses encap-tracing {
when "derived-from-or-self(node-action,
'ioam:action-encapsulate')";
}
leaf flow-id {
when "derived-from-or-self(../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.";
}
leaf enable-sequence-number {
when "derived-from-or-self(../node-action,
'ioam:action-encapsulate')";
type boolean;
default false;
description
"This boolean value indicates whether the sequence number is
used in the direct export option 32-bit flow identifier. If
this value is true, the sequence number is used. By default,
it's turned off.";
}
}
grouping ioam-e2e-profile {
description
"A grouping for edge-to-edge profile.";
leaf node-action {
type ioam-node-action;
default action-transit;
description
"This object indicates the action the node need to
take, e.g. encapsulation.";
}
container e2e-types {
when "derived-from-or-self(../node-action,
'ioam:action-encapsulate')";
description
"It indicates the list of edge-to-edge types for
encapsulation.";
leaf use-namespace {
type ioam-namespace;
default default-namespace;
description
"It indicates the name space used for encapsulation.";
}
leaf-list e2e-type {
type ioam-e2e-type;
description
"The edge-to-edge 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
"This object is to control the availability of configuration.
It MUST be true before anything in the
/ioam/profiles/profile subtree can be edited.
If false, any configuration in place is not used.";
}
}
/*
* DATA NODES
*/
container ioam {
description "IOAM top level container";
container info {
config false;
description
"Describes information such as units or timestamp format that
assists monitoring systems in the interpretation of 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";
description
"A list of available interfaces that support IOAM.";
leaf if-name {
type if:interface-ref;
description "This is a reference to the Interface name.";
}
}
}
container admin-config {
description
"Contains all the administrative configurations related to
the IOAM functionalities and all the IOAM profiles.";
uses ioam-admin-config;
}
container profiles {
description
"Contains a list of IOAM profiles.";
list profile {
key "profile-name";
description
"A list of IOAM profiles that configured on the node.
There is no mandatory type of profile (e.g.,
incremental-trace, preallocated-trace.) in the list.
But at least one profile should be added.";
leaf profile-name {
type string{
length "1..300";
}
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;
presence "Enables incremental tracing option.";
description
"It describes the profile for incremental tracing
option.";
uses ioam-incremental-tracing-profile;
}
container preallocated-tracing-profile {
if-feature preallocated-trace;
presence "Enables preallocated tracing option.";
description
"It describes the profile for preallocated tracing
option.";
uses ioam-preallocated-tracing-profile;
}
container direct-export-profile {
if-feature direct-export;
presence "Enables direct-export option.";
description
"It describes the profile for direct-export option";
uses ioam-direct-export-profile;
}
container pot-profile {
if-feature proof-of-transit;
presence "Enables Proof of Transit option.";
description
"It describes the profile for PoT option.";
leaf use-namespace {
type ioam-namespace;
default default-namespace;
description
"It indicates the namespace used for the POT types.";
}
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;
presence "Enables edge-to-edge option.";
description
"It describes the profile for edge-to-edge option.";
uses ioam-e2e-profile;
}
}
}
}
}
]]>The YANG module specified in this document defines a schema for data
that is designed to be accessed via network management protocols such as
NETCONF or RESTCONF. The lowest NETCONF layer is the secure
transport layer, and the mandatory-to-implement secure transport is
Secure Shell (SSH). The lowest RESTCONF
layer is HTTPS, and the mandatory-to-implement secure transport is TLS.The Network Configuration Access Control Model
(NACM) 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:/ioam/admin-config: 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./ioam/profiles/profile: The entries in the list above include the
whole IOAM profile configurations. Unexpected changes to these
entries could lead to the mistake of the IOAM behavior for the
corresponding flows. Consequently, it will impact the performance
monitoring, data analytics, and the associated reaction to network
services.Some readable data nodes in these YANG modules may be considered
sensitive or vulnerable in some network environments. It is thus
important to control read access (e.g., via get, get-config, or
notification) to these data nodes. These are the subtrees and data nodes
and their sensitivity/vulnerability:/ioam/profiles/profile: The information contained in this subtree
might give information about the services deployed for the
customers.For instance, a customer might be given access to monitor
their services status. In that example, the customer access should
be restricted to nodes representing their services so as not to
divulge information about the underlying network structure or
services.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. The following URI is
suggested:This document also requests a new YANG module name in the YANG Module Names registry with the following
suggestion:For their valuable comments, discussions, and feedback, we wish to
acknowledge Greg Mirsky, Reshad Rahman, Tom Petch, Mickey Spiegel,
Thomas Graf, Alex Huang Feng and Justin Iurman.An example of incremental tracing profile is depicted in the
following figure. This configuration is received by an IOAM ingress
node. This node encapsulates the IOAM data in IPv6 Hop-by-Hop option
header. The trace type indicates that each on path node need to capture
the transit delay, and add to the IOAM node data list. The incremental
tracing data space is variable, however, the node data list must not
exceed 512 bytes.trueietf-test-profileipv6action-encapsulatedefault-namespacetrace-transit-delay512
]]>An example of pre-allocated tracing profile is depicted in the
following figure. This configuration is received by an IOAM ingress
node. This node firstly identifies the target flow by using ACL
"test-acl", and then encapsulates the IOAM data in the NSH header. The
trace type indicates that each on path node need to capture the name
space specific data in the short format, and add to the IOAM node data
list. This node preallocates the node data list in the packect with 512
bytes.trueietf-test-profileacl-filtertest-aclnshaction-encapsulatedefault-namespacetrace-namespace-data512
]]>An example of direct export profile is depicted in the following
figure. This configuration is received by an IOAM egress node. This node
detects the IOAM direct export option in the IPv6 extension header, and
removes the option to clean all the IOAM data.trueietf-test-profileipv6action-decapsulate
]]>The following figure is a simple example of POT option. This
configuration indicates the node to apply POT type 0 with IPv6
encapsulation.trueietf-test-profileipv6pot-type-0
]]>The following figure shows an example of edge-to-edge option. This
configuration is received by an IOAM egress node. This node detects the
IOAM edge-to-edge option in the IPv6 extension header, and removes the
option to clean all the IOAM data. As the IOAM egress node, it may
collect the edge-to-edge data and deliver to the data exporting
process.trueietf-test-profileipv6action-decapsulate
]]>