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) 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.In-situ Operations, Administration, and Maintenance (IOAM) 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 . 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. 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.The "ioam-info" is a container for all the read only assistant
information, so that monitoring systems can interpret the IOAM
data.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 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.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
"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:enabled: indicates whether the preallocated tracing profile is
enabled.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: indicate 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.Loopback mode is used to send a copy of a packet back towards
the source.Active mode indicates that a packet is used for active
measurement.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.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.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 , 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:enabled: indicates whether the edge to edge profile is
enabled.node-action is the same semantic as in Section 2.2.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.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/ioam-profiles/admin-configThe 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/ioam-profiles/ioam-profileThe 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. 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 and Mickey
Spiegel.This appendix is non-normative.tbd