Internet DRAFT - draft-contreras-opsawg-scheduling-oam-tests
draft-contreras-opsawg-scheduling-oam-tests
OPSAWG Working Group L. M. Contreras
Internet-Draft Telefonica
Intended status: Standards Track 13 March 2023
Expires: 14 September 2023
A YANG Data Model for Network Diagnosis by scheduling sequences of OAM
tests
draft-contreras-opsawg-scheduling-oam-tests-00
Abstract
This document defines a YANG data model for network diagnosis on-
demand using Operations, Administration, and Maintenance (OAM) tests.
This document defines both 'oam-unitary-test' and 'oam-test-sequence'
data models to enable on-demand activation of network diagnosis
procedures.
The YANG data model defined in this document conforms to the Network
Management Datastore Architecture (NMDA).
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
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on 14 September 2023.
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/
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Please review these documents carefully, as they describe your rights
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extracted from this document must include Revised BSD License text as
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology and Notations . . . . . . . . . . . . . . . . 3
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
1.3. Prefix in Data Node Names . . . . . . . . . . . . . . . . 4
2. Network wide OAM use cases . . . . . . . . . . . . . . . . . 4
2.1. Troubleshooting . . . . . . . . . . . . . . . . . . . . . 5
2.2. Birth certificate . . . . . . . . . . . . . . . . . . . . 5
2.3. Proactive supervision . . . . . . . . . . . . . . . . . . 6
2.4. Performance-based Path Routing . . . . . . . . . . . . . 6
3. YANG Data Model for scheduling OAM Tests . . . . . . . . . . 6
3.1. YANG Model Overview . . . . . . . . . . . . . . . . . . . 6
3.2. Tree Diagram for scheduling OAM Tests . . . . . . . . . . 6
3.3. YANG Model for scheduling OAM Tests . . . . . . . . . . . 6
4. Security Considerations . . . . . . . . . . . . . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6. Implementation Status . . . . . . . . . . . . . . . . . . . . 7
7. Normative References . . . . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
Operations, Administration, and Maintenance (OAM) tasks are
fundamental functionalities of the network management. Given the
emerging of data models and their utilization in Service Provider's
management, the management of OAM tests represent also an area of
interest for operators, which requires to be defined as a data model.
OAM functionalities provide the means to identify and isolate faults,
measure and report of performance. [RFC5860] defines the three main
areas involved in OAM:
* Fault management, which allows network operators to quickly
identify and isolate faults in the network. The OAM framework
defines mechanisms for fault detection and isolation, such as
continuity check, link trace, and loopback.
* Performance management enables monitoring network performance and
diagnosing performance issues (i.e., degradation). Some of the
measurements such as frame delay measurement, frame delay
variation measurement, and frame loss measurement.
* Security management defines mechanisms to protect OAM
communications from unauthorized access and tampering.
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[RFC6428] defines several use cases for OAM tools, including:
* Continuity Check: This function verifies that a path exists
between two points in a network and that the path is operational.
* Loopback: This function allows a device to loop back a received
packet back to the sender for diagnostic purposes.
* Link Trace: This function allows a network operator to trace a
path through a network from one device to another.
* Performance Monitoring: This function allows a network operator to
monitor the performance of a network and to identify and diagnose
performance issues.
* Security Management: This function allows a network operator to
protect OAM communications from unauthorized access and tampering.
* Configuration Management: This function allows a network operator
to manage the configuration of network devices.
On one hand [RFC8531], [RFC8532] and, [RFC8533] defined YANG models
for OAM technologies. On the other hand, [RFC8531] defines a YANG
data model for connection-oriented OAM protocols. The main aim of
this document is to define a generic YANG data model that can be used
to configure, control and monitor connection-oriented OAM protocols
such as MPLS-TP OAM, PBB-TE OAM, and G.7713.1 OAM. [RFC8532]
provides a generic YANG data model that can be used to configure,
control and monitor connectionless OAM protocols such as BFD
(Bidirectional Forwarding Detection), LBM (Loopback Messaging) and
VCCV (Virtual Circuit Connectivity Verification). [RFC8533] provides
a YANG data model that can be used to retrieve information related to
OAM protocols such as Bidirectional Forwarding Detection (BFD),
Loopback Messaging (LBM) and Virtual Circuit Connectivity
Verification (VCCV).
Previous RFCs defined the parameters required for each of the
different tests that are used in network elements today. This
document covers how to use OAM for network-wide use cases.
Following, some illustrative examples are presented.
The YANG data model resulting from this document will conform to the
Network Management Datastore Architecture (NMDA) [RFC8342].
1.1. Terminology and Notations
This document assumes that the reader is familiar with the contents
of [RFC7950], [RFC8345], [RFC8346] and [RFC8795].
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Following terms are used for the representation of this data model.
* OAM unitary test: it is a set of parameters that define a type of
OAM test to be invoked. As an example, it includes the type test,
configuration parameters, and target results.
* OAM test sequence: it is a set of OAM unitary tests that are run
based on a set of time constraints, number of repetitions, order,
and reporting outputs.
1.2. 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
[RFC2119], [RFC8174] when, and only when, they appear in all
capitals, as shown here.
1.3. Prefix in Data Node Names
In this document, names of data nodes and other data model objects
will be prefixed using the standard prefix associated with the
corresponding YANG imported modules, as shown in the following table.
+========+========================+===========+
| Prefix | Yang Module | Reference |
+========+========================+===========+
| oamut | ietf-oam-unitary-tests | RFCXXX |
+--------+------------------------+-----------+
| oamts | ietf-oam-test-sequence | RFCXXX |
+--------+------------------------+-----------+
| yang | ietf-yang-types | [RFC6991] |
+--------+------------------------+-----------+
Table 1: Prefixes and corresponding YANG
modules
RFC Editor Note: Please replace XXXX with the RFC number assigned to
this document if the document becomes a RFC. Please remove this note
in that case.
2. Network wide OAM use cases
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2.1. Troubleshooting
After the detection of a problem in the network, OAM tests are
performed to find the root cause for the detected issue. However, a
problem detected can be caused by a variety of factors, such as a
misconfiguration, hardware failure, or a software bug. OAM tests can
help to find the root cause by testing specific components of the
network and looking for anomalies or issues.
There are a variety of different OAM tests that can be executed
depending on the nature of the scenario. For example, if the issue
is related to a L2 capability, tests can be run to check the status
of the path via Ethernet Linktrace and later run an Ethernet Loopback
to a concrete network element. If these tests are correct, the
operator may want to check the availability of the service or its
performance.
Even though the troubleshooting process may be different depending on
the problem detected, there are certain common procedures or logic
that can be executed in order to narrow down the cause of the
problem.
2.2. Birth certificate
The aim of a birth certificate process is to validate that all
relevant parameters are correct for a specific network service. The
birth certificate process is done once the configuration of the
network elements is completed and they are ready for service.
If the birth certificate is successful, it means that the network
service is functioning correctly and meets the requirements defined
by the operator. The process requires running a set of OAM tests to
verify that the service is performing as expected.
The set of OAM tests done as part of a birth certificate process
depends on the network service that is tested. For example, if the
service is a virtual private network (VPN) Two-Way Active Measurement
Protocol (TWAMP) Light will be used, while if the service is an
E-LINE, Ethernet CFM tests will be executed.
Once the birth certificate process has been completed and the OAM
tests have been run, the test results are stored as part of the
documentation process performed by the operator.
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2.3. Proactive supervision
There are communication services that require to fulfill Service
Level Agreements (SLAs). SLAs define performance parameters that the
service must fulfill in order to meet the requirements of the
customer or end user.
Proactive testing ensures the SLAs are met. Proactive supervision
requires running tests on service components to identify and resolve
issues before they impact the customer or end user, or to minimize
the impact of the end user.
Proactive testing can be done via OAM tests. These tests can be run
periodically at regular intervals depending on the specific SLA
requirements and the network operator procedures. These procedures
may require documenting the test results for future auditing
processes with the customers.
2.4. Performance-based Path Routing
Path Computation Elements (PCEs) allow computing end-to-end paths in
a network. PCEs are used to facilitate traffic engineering and can
be used to optimize network performance, reduce congestion, and
improve the overall user experience.
There are different algorithms to calculate a path in the network for
some of them the PCE requires traffic engineering information. TE
information includes data such as link metrics, bandwidth
availability, and routing constraints. By using this information,
the PCE can compute the optimal path for a particular service, taking
into account its constraints and requirements. OAM techniques allow
obtaining link metrics like delay and loss which can be used in the
PCE algorithms.
3. YANG Data Model for scheduling OAM Tests
3.1. YANG Model Overview
TBC
3.2. Tree Diagram for scheduling OAM Tests
TBC
3.3. YANG Model for scheduling OAM Tests
TBC
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4. Security Considerations
The YANG module targeted 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.
5. IANA Considerations
TBC
6. Implementation Status
This section will be used to track the status of the implementations
of the model. It is aimed at being removed if the document becomes
RFC.
7. 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/rfc/rfc2119>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<https://www.rfc-editor.org/rfc/rfc5246>.
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[RFC5860] Vigoureux, M., Ed., Ward, D., Ed., and M. Betts, Ed.,
"Requirements for Operations, Administration, and
Maintenance (OAM) in MPLS Transport Networks", RFC 5860,
DOI 10.17487/RFC5860, May 2010,
<https://www.rfc-editor.org/rfc/rfc5860>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/rfc/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/rfc/rfc6242>.
[RFC6428] Allan, D., Ed., Swallow, G., Ed., and J. Drake, Ed.,
"Proactive Connectivity Verification, Continuity Check,
and Remote Defect Indication for the MPLS Transport
Profile", RFC 6428, DOI 10.17487/RFC6428, November 2011,
<https://www.rfc-editor.org/rfc/rfc6428>.
[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536,
DOI 10.17487/RFC6536, March 2012,
<https://www.rfc-editor.org/rfc/rfc6536>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/rfc/rfc6991>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/rfc/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/rfc/rfc8040>.
[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/rfc/rfc8174>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/rfc/rfc8342>.
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[RFC8345] Clemm, A., Medved, J., Varga, R., Bahadur, N.,
Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
2018, <https://www.rfc-editor.org/rfc/rfc8345>.
[RFC8346] Clemm, A., Medved, J., Varga, R., Liu, X.,
Ananthakrishnan, H., and N. Bahadur, "A YANG Data Model
for Layer 3 Topologies", RFC 8346, DOI 10.17487/RFC8346,
March 2018, <https://www.rfc-editor.org/rfc/rfc8346>.
[RFC8531] Kumar, D., Wu, Q., and Z. Wang, "Generic YANG Data Model
for Connection-Oriented Operations, Administration, and
Maintenance (OAM) Protocols", RFC 8531,
DOI 10.17487/RFC8531, April 2019,
<https://www.rfc-editor.org/rfc/rfc8531>.
[RFC8532] Kumar, D., Wang, Z., Wu, Q., Ed., Rahman, R., and S.
Raghavan, "Generic YANG Data Model for the Management of
Operations, Administration, and Maintenance (OAM)
Protocols That Use Connectionless Communications",
RFC 8532, DOI 10.17487/RFC8532, April 2019,
<https://www.rfc-editor.org/rfc/rfc8532>.
[RFC8533] Kumar, D., Wang, M., Wu, Q., Ed., Rahman, R., and S.
Raghavan, "A YANG Data Model for Retrieval Methods for the
Management of Operations, Administration, and Maintenance
(OAM) Protocols That Use Connectionless Communications",
RFC 8533, DOI 10.17487/RFC8533, April 2019,
<https://www.rfc-editor.org/rfc/rfc8533>.
[RFC8795] Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
O. Gonzalez de Dios, "YANG Data Model for Traffic
Engineering (TE) Topologies", RFC 8795,
DOI 10.17487/RFC8795, August 2020,
<https://www.rfc-editor.org/rfc/rfc8795>.
Author's Address
Luis M. Contreras
Telefonica
Ronda de la Comunicacion, s/n
28050 Madrid
Spain
Email: luismiguel.contrerasmurillo@telefonica.com
URI: http://lmcontreras.com
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