Hi Mallory,
thank you for the review and your thoughtful comments that helped improve the draft. Please find my notes below tagged GIM>>. Attached, is the updated working version that includes changes addressing your comments.
Regards,
Greg
On Mon, Dec 18, 2023 at 12:58 PM Mallory Knodel via Datatracker <noreply@xxxxxxxx> wrote:
Reviewer: Mallory Knodel
Review result: Ready with Nits
I am the assigned Gen-ART reviewer for this draft. The General Area
Review Team (Gen-ART) reviews all IETF documents being processed
by the IESG for the IETF Chair. Please treat these comments just
like any other last call comments.
For more information, please see the FAQ at
<https://wiki.ietf.org/en/group/gen/GenArtFAQ>.
Document: draft-ietf-detnet-oam-framework-??
Reviewer: Mallory Knodel
Review Date: 2023-12-18
IETF LC End Date: 2023-12-19
IESG Telechat date: Not scheduled for a telechat
Summary: The document summarizes the OAM requirements of DetNet networks. The
document provides a good background of the necessary OAM components and
presents the requirements of the OAM solutions.
Major issues:
* Figure should be svg because on a device that rewraps the text this will get
(is already) totally messed up on smaller screens.
GIM>> I'll gladly convert from ASCII-art to a friendlier format. Could you help me to find a reference to the process?
* Suggest a privacy
considerations section that at least references the text in rfc9055, or
perhaps elaborates on it given the OAM provides a lot of signals.
GIM>> Thank you for the suggestion. Please consider the following:
NEW TEXT:
9. Privacy Considerations
Privacy considerations of DetNet discussed in Section 13 of [RFC9055]
are also applicable to DetNet OAM. If any privacy mechanism is used
for the monitored DetNet flow, then the same privacy method MUST be
applied to the active DetNet OAM used to monitor the flow.
Minor issues:
* It seems to me that there is no meaningful difference between definitions
and terminology so perhaps just collapse these two sections, or provide some
other compelling reason to present them separately to the reader.
GIM>> Thank you for pointing this out to me. I think that the "Terminology" is not reflective of the content. Perhaps s/Terminology/Abbreviations/ is more suitable?
* This is a
general review and I am not an expert so take this for what it's worth, but I
am unclear on why there would be so many MUSTs for monitoring requirements and
perhaps they should be should?
GIM>> Thank you for a great question! In my opinion, a normative recommendation might be the source of interoperability concerns for cases when an implementation doesn't support the recommended behavior. Also, more options usually result in a more complex implementation. DetNet WG discussed the requirements for DetNet OAM and has agreed with the normative language used.
Nits/editorial comments:
* 5. Are the paragraph indents intended to be bulleted or numbered?
GIM>> Thank you for catching it. For the sake of consistency, I switched to the default bullet, i.e., '*'.
* 6.1 and 6.2 subtitles can remove "Requirements on OAM for DetNet" as they
are redundant
GIM>> Agreed. Please check the attached working version.
DetNet G. Mirsky
Internet-Draft Ericsson
Intended status: Informational F. Theoleyre
Expires: 21 June 2024 CNRS
G.Z. Papadopoulos
IMT Atlantique
CJ. Bernardos
UC3M
B. Varga
J. Farkas
Ericsson
19 December 2023
Framework of Operations, Administration and Maintenance (OAM) for
Deterministic Networking (DetNet)
draft-ietf-detnet-oam-framework-10
Abstract
Deterministic Networking (DetNet), as defined in RFC 8655, aims to
provide bounded end-to-end latency on top of the network
infrastructure, comprising both Layer 2 bridged and Layer 3 routed
segments. This document's primary purpose is to detail the specific
requirements of the Operation, Administration, and Maintenance (OAM)
recommended to maintain a deterministic network. The document will
be used in future work that defines the applicability of and
extension of OAM protocols for a deterministic network. With the
implementation of the OAM framework in DetNet, an operator will have
a real-time view of the network infrastructure regarding the
network's ability to respect the Service Level Objective, such as
packet delay, delay variation, and packet loss ratio, assigned to
each DetNet flow.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). 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."
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This Internet-Draft will expire on 21 June 2024.
Copyright Notice
Copyright (c) 2023 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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4
1.3. Requirements Language . . . . . . . . . . . . . . . . . . 5
2. Role of OAM in DetNet . . . . . . . . . . . . . . . . . . . . 5
3. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. Information Collection . . . . . . . . . . . . . . . . . 7
3.2. Continuity Check . . . . . . . . . . . . . . . . . . . . 7
3.3. Connectivity Verification . . . . . . . . . . . . . . . . 7
3.4. Route Tracing . . . . . . . . . . . . . . . . . . . . . . 8
3.5. Fault Verification/Detection . . . . . . . . . . . . . . 8
3.6. Fault Localization and Characterization . . . . . . . . . 8
3.7. Use of Hybrid OAM in DetNet . . . . . . . . . . . . . . . 9
4. Administration . . . . . . . . . . . . . . . . . . . . . . . 9
4.1. Collection of metrics . . . . . . . . . . . . . . . . . . 10
4.2. Worst-case metrics . . . . . . . . . . . . . . . . . . . 10
5. Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1. Replication / Elimination . . . . . . . . . . . . . . . . 11
5.2. Resource Reservation . . . . . . . . . . . . . . . . . . 11
6. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. For the DetNet Forwarding Sub-layer . . . . . . . . . . . 12
6.2. For the DetNet Service Sub-layer . . . . . . . . . . . . 12
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8. Security Considerations . . . . . . . . . . . . . . . . . . . 13
9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 13
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
11.1. Normative References . . . . . . . . . . . . . . . . . . 14
11.2. Informative References . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
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1. Introduction
Deterministic Networking (DetNet) [RFC8655] has proposed to provide a
bounded end-to-end latency on top of the network infrastructure,
comprising both Layer 2 bridged and Layer 3 routed segments. That
work encompasses the data plane, OAM, time synchronization,
management, control, and security aspects.
Operations, Administration, and Maintenance (OAM) Tools are of
primary importance for IP networks [RFC7276]. DetNet OAM should
provide a toolset for fault detection, localization, and performance
measurement.
This document's primary purpose is to detail the specific
requirements of the OAM features recommended to maintain a
deterministic/reliable network. Specifically, it investigates the
requirements for a deterministic network, supporting critical flows.
In this document, the term OAM will be used according to its
definition specified in [RFC6291]. DetNet expects to implement an
OAM framework to maintain a real-time view of the network
infrastructure, and its ability to respect the Service Level
Objectives (SLOs), such as in-order packet delivery, packet delay,
delay variation, and packet loss ratio, assigned to each DetNet flow.
This document lists the functional requirements toward OAM for a
DetNet domain. The list can further be used for gap analysis of
available OAM tools to identify possible enhancements of existing or
whether new OAM tools are required to support proactive and on-demand
path monitoring and service validation.
1.1. Definitions
This document uses definitions, particularly of a DetNet flow,
provided in Section 2.1 of [RFC8655]. The following terms are used
throughout this document as defined below:
* DetNet OAM domain: a DetNet network used by the monitored DetNet
flow. A DetNet OAM domain (also referred to in this document as
"OAM domain") may have MEPs on its edge and MIPs within.
* DetNet OAM instance: a function that monitors a DetNet flow for
defects and/or measures its performance metrics. Within this
document, a shorter version, OAM instance, is used
interchangeably.
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* Maintenance End Point (MEP): an OAM instance that is capable of
generating OAM test packets in the particular sub-layer of the
DetNet OAM domain.
* Maintenance Intermediate Point (MIP): an OAM instance along the
DetNet flow in the particular sub-layer of the DetNet OAM domain.
An active MIP MUST respond to an OAM message generated by the MEP
at its sub-layer of the same DetNet OAM domain.
* Control and management plane: the control and management planes
are used to configure and control the network. Relative to a
DetNet flow, the control and/or management plane can be out-of-
band.
* Active measurement methods (as defined in [RFC7799]) modify a
DetNet flow by injecting specially constructed test packets
[RFC2544]).
* Passive measurement methods [RFC7799] infer information by
observing unmodified existing flows.
* Hybrid measurement methods [RFC7799] is the combination of
elements of both active and passive measurement methods.
* In-band OAM is an active OAM that is in-band within the monitored
DetNet OAM domain when it traverses the same set of links and
interfaces receiving the same QoS and Packet Replication,
Elimination, and Ordering Functions (PREOF) treatment as the
monitored DetNet flow.
* Out-of-band OAM is an active OAM whose path through the DetNet
domain is not topologically identical to the path of the monitored
DetNet flow, or its test packets receive different QoS and/or
PREOF treatment, or both.
* On-path telemetry can be realized as a hybrid OAM method. The
origination of the telemetry information is inherently in-band as
packets in a DetNet flow are used as triggers. Collection of the
on-path telemetry information can be performed using in-band or
out-of-band OAM methods.
1.2. Abbreviations
OAM: Operations, Administration, and Maintenance
DetNet: Deterministic Networking
PREOF: Packet Replication, Elimination and Ordering Functions
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SLO: Service Level Objective
1.3. Requirements Language
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 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. The requirements language is used in
Section 1.1, Section 6, and applies to the implementations of DetNet
OAM.
2. Role of OAM in DetNet
DetNet networks expect to provide communications with predictable low
packet delay, packet loss, and packet misordering. Most critical
applications will define a set of SLOs to be required for the DetNet
flows it generates.
To respect strict guarantees, DetNet can use an orchestrator able to
monitor and maintain the network. Typically, a Software-Defined
Network controller places DetNet flows in the deployed network based
on their SLOs. Thus, resources have to be provisioned a priori for
the regular operation of the network.
Many legacy OAM tools can be used in DetNet networks, but they are
not able to cover all the aspects of deterministic networking.
Fulfilling strict guarantees is essential for DetNet flows, resulting
in new DetNet-specific functionalities that must be covered with OAM.
Filling these gaps is inevitable and needs accurate consideration of
DetNet specifics. Similar to DetNet flows themselves, their OAM
needs careful end-to-end engineering as well.
For example, appropriate placing of MEPs along the path of a DetNet
flow is not always a trivial task and may require proper design,
together with the design of the service component of a given DetNet
flow.
There are several DetNet-specific challenges for OAM. Bounded
network characteristics (e.g., delay, loss) are inseparable service
parameters; therefore, Performance Monitoring OAM is a key topic for
DetNet. OAM tools are needed to monitor each SLO without impacting
the DetNet flow characteristics. A further challenge is strict
resource allocation. Resources used by OAM must be considered and
allocated to avoid disturbing DetNet flows.
The DetNet Working Group has defined two sub-layers:
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DetNet service sub-layer, at which a DetNet service (e.g., service
protection) is provided.
DetNet forwarding sub-layer, which optionally provides resource
allocation for DetNet flows over paths provided by the underlying
network.
OAM mechanisms exist for the DetNet forwarding sub-layer, but the
service sub-layer requires new OAM procedures. These new OAM
functions must allow, for example, to recognize/discover DetNet relay
nodes, to get information about their configuration, and to check
their operation or status.
DetNet service sub-layer functions use a sequence number for PREOF.
That creates a challenge for inserting OAM packets in the DetNet
flow.
Fault tolerance also assumes that multiple paths could be provisioned
to maintain an end-to-end circuit by adapting to the existing
conditions. The DetNet Controller Plane, e.g., central controller/
orchestrator, controls the PREOF on a node. OAM is expected to
support monitoring and troubleshooting PREOF on a particular node and
within the domain.
Note that a distributed architecture of the DetNet Control Plane can
also control PREOF in those scenarios where DetNet solutions involve
more than one single central controller.
The DetNet forwarding sub-layer is based on preexisting technologies
and has much better coverage regarding OAM. However, the forwarding
sub-layer is terminated at DetNet relay nodes, so the end-to-end OAM
state of forwarding may be created only based on the status of
multiple forwarding sub-layer segments serving a given DetNet flow
(e.g., in case of DetNet MPLS, there may be no end-to-end LSP below
the DetNet Pseudowire).
3. Operation
OAM features will enable DetNet with robust operation both for
forwarding and routing purposes.
It is worth noting that the test and data packets are expected to
follow the same path, i.e., connectivity verification has to be
conducted in-band without impacting data traffic. It is expected
that test packets share fate with the monitored data traffic without
introducing congestion in normal network conditions.
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3.1. Information Collection
Information about the state of the network can be collected using
several mechanisms. Some protocols, e.g., Simple Network Management
Protocol, send queries. Others, e.g., YANG-based data models,
generate notifications based on the publish-subscribe method. In
either way, information is collected and sent using the DetNet
Controller Plane.
Also, we can characterize methods of transporting OAM information
relative to the path of data. For instance, OAM information may be
transported in-band or out-of-band relative to the DetNet flow. In
case of the former, the telemetry information uses resources
allocated for the monitored DetNet flow. If an in-band method of
transporting telemetry is used, the amount of generated information
needs to be carefully analyzed, and additional resources must be
reserved. [RFC9197] defines the in-band transport mechanism where
telemetry information is collected in the data packet on which
information is generated. Two tracing methods are described - end-
to-end, i.e., from the ingress and egress nodes, and hop-by-hop,
i.e., like end-to-end with additional information from transit nodes.
[RFC9326] and [I-D.mirsky-ippm-hybrid-two-step] are examples of out-
of-band telemetry transport. In the former case, information is
transported by each node traversed by the data packet of the
monitored DetNet flow in a specially constructed packet. In the
latter, information is collected in a sequence of follow-up packets
that traverse the same path as the data packet of the monitored
DetNet flow. In both methods, transport of the telemetry can avoid
using resources allocated for the DetNet domain.
3.2. Continuity Check
Continuity check is used to monitor the continuity of a path, i.e.,
that there exists a way to deliver packets between MEP A and MEP B.
The continuity check detects a network failure in one direction, from
the MEP transmitting test packets to the remote egress MEP.
Continuity check in a DetNet OAM domain monitors the DetNet
forwarding sub-layer and thus is not affected by a PREOF that
operates at the DetNet service sub-layer ([RFC8655].
3.3. Connectivity Verification
In addition to the Continuity Check, DetNet solutions have to verify
connectivity. This verification considers an additional constraint,
i.e, the absence of misconnection. The misconnection error state is
entered after several consecutive test packets from other DetNet
flows are received. The definition of the conditions for entry and
exit of a misconnection error state is outside the scope of this
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document. Connectivity verification in a DetNet OAM domain monitors
the DetNet forwarding sub-layer and thus is not affected by PREOF
that operates at the DetNet service sub-layer ([RFC8655].
3.4. Route Tracing
Ping and traceroute are two ubiquitous tools that help localize and
characterize a failure in the network using an echo request/reply
mechanism. They help to identify a subset of the routers in the
path. However, to be predictable, resources are reserved per flow in
DetNet. Thus, DetNet needs to define route tracing tools able to
trace the route for a specific flow. Also, tracing can be used for
the discovery of the Path Maximum Transmission Unit or location of
elements of PREOF for the particular route in the DetNet domain.
DetNet is not expected to use Equal-Cost Multipath (ECMP) [RFC8939].
As the result, DetNet OAM in an ECMP environment is outside the scope
of this document.
3.5. Fault Verification/Detection
DetNet expects to operate fault-tolerant networks. Thus, mechanisms
able to detect faults before they impact network performance are
needed.
The network has to detect when a fault has occurred, i.e., the
network has deviated from its expected behavior. Fault detection can
be based on proactive OAM protocols like continuity check or on-
demand methods like ping. While the network must report an alarm,
the cause may not be identified precisely. Examples of such alarms
are significant degradation of the end-to-end reliability, or a
buffer overflow occurs.
3.6. Fault Localization and Characterization
An ability to localize a network defect and provide its
characterization are necessary elements of network operation.
Fault localization, a process of deducing the location of a
network failure from a set of observed failure indications, might
be achieved, for example, by tracing the route of the DetNet flow
in which the network failure was detected. Another method of
fault localization can correlate reports of failures from a set of
interleaved sessions monitoring path continuity.
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Fault characterization is a process of identifying the root cause
of the problem. For instance, misconfiguration or malfunction of
PREOF elements can be the cause of erroneous packet replication or
extra packets being flooded in the DetNet domain.
3.7. Use of Hybrid OAM in DetNet
Hybrid OAM methods are used in performance monitoring and defined in
[RFC7799] as:
Hybrid Methods are Methods of Measurement that use a combination
of Active Methods and Passive Methods.
A hybrid measurement method can produce metrics as close to measured
using a passive measurement method. The passive methods measure
metrics closest to the network's actual conditions. A hybrid method,
even if it alters something in a data packet, even if that is as
little as the value of a designated field in the packet
encapsulation, is considered an approximation of a passive
measurement method. One example of such a hybrid measurement method
is the Alternate Marking method (AMM) described in [RFC9341]. As
with all on-path telemetry methods, AMM in a DetNet domain with the
IP data plane is natively in-band with respect to the monitored
DetNet flow. Because the marking is applied to a data flow, measured
metrics are directly applicable to the DetNet flow. AMM minimizes
the additional load on the DetNet domain by using nodal collection
and computation of performance metrics in combination with optionally
using out-of-band telemetry collection for further network analysis.
4. Administration
The ability to expose a collection of metrics to support an
operator's decision-making is essential. The following performance
metrics are useful:
* Queuing Delay: the time elapsed between enqueuing a packet and its
transmission to the next hop.
* Buffer occupancy: the number of packets present in the buffer, for
each of the existing flows.
* Per DetNet flow, a metric reflecting end-to-end performance for a
given flow. Each of the paths has to be isolated in a multipath
routing environment.
* Per path, detection of misbehaving path(s) when multiple paths are
used for the service protection.
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* Per device, detection of a misbehaving device.
4.1. Collection of metrics
It is important to optimize the volume and frequency of statistics/
measurement collection, whether the mechanisms are distributed,
centralized, or both. Periodic and event-triggered collection
information characterizing the state of a network is an example of
mechanisms to achieve the optimization.
4.2. Worst-case metrics
DetNet aims to enable real-time communications on top of a
heterogeneous multi-hop architecture. To make correct decisions, the
DetNet Controller Plane [RFC8655] needs timely information about
packet losses/delays for each flow, and each hop of the paths. In
other words, just the average end-to-end statistics are not enough.
The collected information must be sufficient to allow a system to
predict the worst-case scenario.
5. Maintenance
Service protection (provided by the DetNet Service sub-layer) is
designed to mitigate simple network failures more rapidly than the
expected response time of the DetNet Controller Plane. In the face
of events that impact network operation (e.g., link up/down, device
crash/reboot, flows starting and ending), the DetNet Controller Plane
needs to perform repair and re-optimization actions in order to
permanently ensure SLOs of all active flows with minimal waste of
resources. The Controller Plane is expected to be able to
continuously retrieve the state of the network, to evaluate
conditions and trends about the relevance of a reconfiguration,
quantifying:
* the cost of the sub-optimality: resources may not be used
optimally (i.e., a better path exists).
* the reconfiguration cost: the DetNet Controller Plane needs an
ability to trigger some reconfigurations. For this transient
period, resources may be twice reserved, and control packets have
to be transmitted.
Thus, reconfiguration may only be triggered if the gain is
significant.
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5.1. Replication / Elimination
When multiple paths are reserved between two MEPs, packet replication
may be used to introduce redundancy and alleviate transmission errors
and collisions. For instance, in Figure 1, the source device S is
transmitting a packet to devices A and B.
===> (A) => (C) => (E) ===
// \\// \\// \\
source (S) //\\ //\\ (R) (root)
\\ // \\ // \\ //
===> (B) => (D) => (F) ===
Figure 1: Packet Replication: S transmits twice the same data
packet, to nodes A and B.
5.2. Resource Reservation
Because the quality of service criteria associated with a path may
degrade, the network has to provision additional resources along the
path.
6. Requirements
According to [RFC8655], DetNet functionality is divided into
forwarding and service sub-layers. The DetNet forwarding sub-layer
includes DetNet transit nodes and may allocate resources for a DetNet
flow over paths provided by the underlay network. The DetNet service
sub-layer includes DetNet relay nodes and provides a DetNet service
(e.g., service protection). This section lists general requirements
for DetNet OAM as well as requirements in each of the DetNet sub-
layers of a DetNet domain.
1. It MUST be possible to initiate a DetNet OAM session from a MEP
located at a DetNet node towards MEP(s) downstream from that
DetNet node within the given domain at a particular DetNet sub-
layer.
2. It MUST be possible to initiate a DetNet OAM session from using
any of DetNet Controller Plane solution, e.g., centralized
controller.
3. DetNet OAM MUST support proactive OAM monitoring and measurement
methods.
4. DetNet OAM MUST support on-demand OAM monitoring and measurement
methods.
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5. DetNet OAM MUST support unidirectional OAM methods, continuity
check, connectivity verification, and performance measurement.
6. OAM methods MAY combine in-band monitoring or measurement in the
forward direction and out-of-bound notification in the reverse
direction, i.e., towards the ingress MEP.
7. DetNet OAM MUST support bi-directional DetNet flows.
8. DetNet OAM MAY support bi-directional OAM methods for bi-
directional DetNet flows. OAM test packets used for monitoring
and measurements MUST be in-band in both directions.
9. DetNet OAM MUST support proactive monitoring of a DetNet device
reachability for a given DetNet flow.
10. DetNet OAM MUST support hybrid performance measurement methods.
11. Calculated performance metrics MUST include but are not limited
to throughput, packet loss, out of order, delay, and delay
variation metrics. [RFC6374] provides detailed information on
performance measurement and performance metrics.
6.1. For the DetNet Forwarding Sub-layer
1. DetNet OAM MUST support Path Maximum Transmission Unit discovery.
2. DetNet OAM MUST support Remote Defect Indication notification to
the DetNet OAM instance performing continuity checking.
3. DetNet OAM MUST support monitoring levels of resources allocated
for a particular DetNet flow. Such resources include but are not
limited to buffer utilization and scheduler transmission
calendar.
4. DetNet OAM MUST support monitoring any subset of paths traversed
through the DetNet domain by a DetNet flow.
6.2. For the DetNet Service Sub-layer
The OAM functions for the DetNet service sub-layer allow, for
example, to recognize/discover DetNet relay nodes, to get information
about their configuration, and to check their operation or status.
The requirements on OAM for a DetNet relay node are:
1. DetNet OAM MUST provide OAM functions for the DetNet service sub-
layer.
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2. DetNet OAM MUST support the discovery of DetNet relay nodes in a
DetNet network.
3. DetNet OAM MUST support the discovery of PREOF locations in the
domain.
4. DetNet OAM MUST support the collection of the DetNet service sub-
layer specific (configuration/operation/status) information from
DetNet relay nodes.
5. DetNet OAM MUST support excercising functionality of PREOF in the
domain.
6. DetNet OAM MUST work for DetNet data planes - MPLS and IP.
7. DetNet OAM MUST support a defect notification mechanism, like
Alarm Indication Signal. Any DetNet relay node providing service
for a given DetNet flow MAY originate a defect notification
addressed to any subset of DetNet relay nodes along that flow.
8. DetNet OAM MUST be able to measure metrics (e.g. delay) inside a
collection of OAM sessions, specially for complex DetNet flows,
with PREOF features.
7. IANA Considerations
This document has no actionable requirements for IANA. This section
can be removed before publication.
8. Security Considerations
This document lists the OAM requirements for a DetNet domain and does
not raise any security concerns or issues in addition to ones common
to networking and those specific to DetNet discussed in Section 9 of
[RFC9055].
9. Privacy Considerations
Privacy considerations of DetNet discussed in Section 13 of [RFC9055]
are also applicable to DetNet OAM. If any privacy mechanism is used
for the monitored DetNet flow, then the same privacy method MUST be
applied to the active DetNet OAM used to monitor the flow.
10. Acknowledgments
The authors express their appreciation and gratitude to Pascal
Thubert for the review, insightful questions, and helpful comments.
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11. References
11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas,
"Deterministic Networking Architecture", RFC 8655,
DOI 10.17487/RFC8655, October 2019,
<https://www.rfc-editor.org/info/rfc8655>.
11.2. Informative References
[I-D.mirsky-ippm-hybrid-two-step]
Mirsky, G., Lingqiang, W., Zhui, G., Song, H., and P.
Thubert, "Hybrid Two-Step Performance Measurement Method",
Work in Progress, Internet-Draft, draft-mirsky-ippm-
hybrid-two-step-15, 15 June 2023,
<https://datatracker.ietf.org/doc/html/draft-mirsky-ippm-
hybrid-two-step-15>.
[RFC2544] Bradner, S. and J. McQuaid, "Benchmarking Methodology for
Network Interconnect Devices", RFC 2544,
DOI 10.17487/RFC2544, March 1999,
<https://www.rfc-editor.org/info/rfc2544>.
[RFC6291] Andersson, L., van Helvoort, H., Bonica, R., Romascanu,
D., and S. Mansfield, "Guidelines for the Use of the "OAM"
Acronym in the IETF", BCP 161, RFC 6291,
DOI 10.17487/RFC6291, June 2011,
<https://www.rfc-editor.org/info/rfc6291>.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374,
DOI 10.17487/RFC6374, September 2011,
<https://www.rfc-editor.org/info/rfc6374>.
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[RFC7276] Mizrahi, T., Sprecher, N., Bellagamba, E., and Y.
Weingarten, "An Overview of Operations, Administration,
and Maintenance (OAM) Tools", RFC 7276,
DOI 10.17487/RFC7276, June 2014,
<https://www.rfc-editor.org/info/rfc7276>.
[RFC7799] Morton, A., "Active and Passive Metrics and Methods (with
Hybrid Types In-Between)", RFC 7799, DOI 10.17487/RFC7799,
May 2016, <https://www.rfc-editor.org/info/rfc7799>.
[RFC8939] Varga, B., Ed., Farkas, J., Berger, L., Fedyk, D., and S.
Bryant, "Deterministic Networking (DetNet) Data Plane:
IP", RFC 8939, DOI 10.17487/RFC8939, November 2020,
<https://www.rfc-editor.org/info/rfc8939>.
[RFC9055] Grossman, E., Ed., Mizrahi, T., and A. Hacker,
"Deterministic Networking (DetNet) Security
Considerations", RFC 9055, DOI 10.17487/RFC9055, June
2021, <https://www.rfc-editor.org/info/rfc9055>.
[RFC9197] Brockners, F., Ed., Bhandari, S., Ed., and T. Mizrahi,
Ed., "Data Fields for In Situ Operations, Administration,
and Maintenance (IOAM)", RFC 9197, DOI 10.17487/RFC9197,
May 2022, <https://www.rfc-editor.org/info/rfc9197>.
[RFC9326] Song, H., Gafni, B., Brockners, F., Bhandari, S., and T.
Mizrahi, "In Situ Operations, Administration, and
Maintenance (IOAM) Direct Exporting", RFC 9326,
DOI 10.17487/RFC9326, November 2022,
<https://www.rfc-editor.org/info/rfc9326>.
[RFC9341] Fioccola, G., Ed., Cociglio, M., Mirsky, G., Mizrahi, T.,
and T. Zhou, "Alternate-Marking Method", RFC 9341,
DOI 10.17487/RFC9341, December 2022,
<https://www.rfc-editor.org/info/rfc9341>.
Authors' Addresses
Greg Mirsky
Ericsson
Email: gregimirsky@xxxxxxxxx
Fabrice Theoleyre
CNRS
300 boulevard Sebastien Brant - CS 10413
67400 Illkirch - Strasbourg
France
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Phone: +33 368 85 45 33
Email: fabrice.theoleyre@xxxxxxx
URI: https://fabrice.theoleyre.cnrs.fr/
Georgios Z. Papadopoulos
IMT Atlantique
Office B00 - 102A
2 Rue de la Châtaigneraie
35510 Cesson-Sévigné - Rennes
France
Phone: +33 299 12 70 04
Email: georgios.papadopoulos@xxxxxxxxxxxxxxxxx
Carlos J. Bernardos
Universidad Carlos III de Madrid
Av. Universidad, 30
28911 Leganes, Madrid
Spain
Phone: +34 91624 6236
Email: cjbc@xxxxxxxxxx
URI: http://www.it.uc3m.es/cjbc/
Balazs Varga
Ericsson
Budapest
Magyar Tudosok krt. 11.
1117
Hungary
Email: balazs.a.varga@xxxxxxxxxxxx
Janos Farkas
Ericsson
Budapest
Magyar Tudosok krt. 11.
1117
Hungary
Email: janos.farkas@xxxxxxxxxxxx
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