Internet DRAFT - draft-mb-mpls-ioam-dex
draft-mb-mpls-ioam-dex
MPLS Working Group G. Mirsky
Internet-Draft Ericsson
Intended status: Standards Track M. Boucadair
Expires: 30 March 2024 Orange
T. Li
Juniper Networks
27 September 2023
Supporting In-Situ OAM Direct Export Using MPLS Network Actions
draft-mb-mpls-ioam-dex-05
Abstract
In-Situ Operations, Administration, and Maintenance (IOAM), defined
in RFC 9197, is an on-path telemetry method to collect and transport
the operational state and telemetry information that can be used to
calculate various performance metrics. IOAM Direct Export (IOAM-DEX)
is one of the IOAM Option types, in which the operational state and
telemetry information are collected according to the specified
profile and exported in a manner and format defined by a local
policy. MPLS Network Actions (MNA) techniques are meant to indicate
actions to be performed on any combination of Label Switched Paths
(LSPs), MPLS packets, and the node itself, and also to transfer data
needed for these actions. This document explores the on-path
operational state, and telemetry information can be collected using
IOAM-DEX Option in combination with MNA.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 30 March 2024.
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Copyright Notice
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document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in this Document . . . . . . . . . . . . . . 3
2.1. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3
3. Applicability of IOAM Option Types in an MPLS Network . . . . 3
4. Realization of IOAM-DEX as an MPLS Network Action . . . . . . 4
4.1. IOAM-DEX Format for an MPLS Network . . . . . . . . . . . 4
4.2. IOAM-DEX-MNA Encoding as In-Stack Data MPLS Network
Action . . . . . . . . . . . . . . . . . . . . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
5.1. IOAM-DEX-MNA as an MPLS Network Action Opcode . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . 7
8.2. Informational References . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
In-Situ OAM (IOAM) [RFC9197] is an on-path telemetry method to
collect and transport the operational state and telemetry information
that can be used to calculate various performance metrics. Several
IOAM Option types (e.g., Pre-allocated and Incremental) use the user
packet to collect the operational state and telemetry information.
Such a mechanism transports the collected information to an IOAM
decapsulating node (typically located at the edge of the IOAM domain
within the data packet). IOAM Direct Export (IOAM-DEX) [RFC9326] is
an IOAM Option type. In IOAM-DEX, the operational state and
telemetry information are collected according to the specified
profile and exported in a manner and format defined by a local
policy. MPLS Network Actions (MNA) techniques
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[I-D.ietf-mpls-mna-fwk] indicate actions to be performed on any
combination of Label Switched Paths (LSPs), MPLS packets, the node
itself, and also allow for the transfer of data needed for these
actions.
This document describes how MNA can be used for collecting on-path
operational state and telemetry information using IOAM-DEX Option.
Specifying the mechanism of exporting collected information is
outside the scope of this document.
2. Conventions Used in this Document
2.1. Acronyms
IOAM: In-Situ OAM
IOAM-DEX: IOAM Direct Export
IOAM-DEX-MNA: IOAM Direct Export in MPLS Network Action
ISD: In-Stack Data
LSP: Label Switched Path
LSE: Label Stack Element
MPLS: Multiprotocol Label Switching
MNA: MPLS Network Action
NAI: Network Action Indicator
2.2. 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 BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Applicability of IOAM Option Types in an MPLS Network
Pre-allocated, Incremental, and Edge-to-Edge IOAM Option types
[RFC9197] use user packets to collect and transport the operational
state and telemetry information. In some environments, for example,
data center networks, this technique is useful as the available
bandwidth and the use of jumbo frames can accommodate the increase of
the packet payload. But for other use cases in which network
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resources are closely controlled, the use of in-band channels for
collecting and transporting the telemetry information may noticeably
decrease the cost-efficiency of network operations. Although the
operational state and telemetry information are essential for network
automation (Section 4 of [RFC8969]), its delivery is not as critical
as user packets. As such, collecting and transporting the
operational state and telemetry information out-of-band using the
management plane is a viable option for some environments. IOAM-DEX
[RFC9326] is used to collect IOAM data defined in [RFC9197]. The
processing and transport of the collected information are controlled
by a local policy which is outside the scope of this specification.
The performance considerations discussed in Section 5 of [RFC9326]
are applicable here.
4. Realization of IOAM-DEX as an MPLS Network Action
4.1. IOAM-DEX Format for an MPLS Network
[I-D.ietf-mpls-mna-usecases] recognizes the importance of IOAM in
MPLS networks and lists it as one of the use cases that might be
supported using MNA techniques. [I-D.ietf-mpls-mna-fwk] defines the
architectural elements that compose MNA. This document uses all the
elements of the IOAM-DEX Option-Type format defined in [RFC9326] to
support IOAM-DEX in an MPLS network using MPLS Network Action (MNA)
framework [I-D.ietf-mpls-mna-fwk] and architecture as in-stack data
(ISD) MNA [I-D.ietf-mpls-mna-hdr]. The format of IOAM-DEX in MNA is
shown in Figure 1.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1| Namespace-ID | Resv |S| Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1| IOAM-Trace-Type-MNA |S|O|R| Ext-Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~1| Extended IOAM-Trace-Type-MNA (Optional) |S| Resv ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1| Flow ID MNA (Optional) |S| Resv |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1| Sequence Number MNA (Optional) |S| Resv |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: IOAM Direct Export Option Type Format in an MPLS
Network Action Framework
Where fields are defined as follows:
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* Namespace-ID is a 16-bit identifier of the IOAM Namespace, as
defined in [RFC9197].
* S is a one-bit the Bottom of Stack [RFC3032].
* Flags is an eight-bit field comprised of eight one-bit subfields.
The subfields in the Flags field are allocated by IANA, as defined
in Section 4.2 of [RFC9326].
* IOAM-Trace-Type-MNA is a 22-bit field. The interpretation of bit
positions in the IOAM-Trace-Type-MNA is as specified in IANA's
IOAM Trace-Type registry [IANA-IOAM-Trace-Type] from Bit 0 through
Bit 21.
* O is the one-bit flag that is identical to the interpretation of
Bit 22 variable-length Opaque State Snapshot in IANA's IOAM Trace-
Type registry [IANA-IOAM-Trace-Type].
* R (Reserved) is a one-bit flag. It MUST be zeroed on the
transmission and ignored on receipt. Similarly to [RFC9197], it
is reserved to allow for future extensions of the IOAM-Trace-Type-
MNA bit field.
* Ext-Flags is a six-bit field comprised of six one-bit subfields.
The allocation of the subfields in the Ext-Flags field is
according to Section 4.3 of [RFC9326]. The allocated flags
indicate the presence of the optional Flow ID and/or Sequence
Number fields in the IOAM-DEX-MNA header. Figure 2 displays the
detailed format of the Ext-Flags field.
* Extended IOAM-Trace-Type-MNA is a 22-bit field. The
interpretation of bit positions is according to IANA's IOAM Trace-
Type registry. An IOAM-DEX-MNA encoding MAY include none, one, or
more LSEs with the Extended IOAM-Trace-Type-MNA field.
* Flow ID MNA is an optional 22-bit field. The semantics of the
Flow ID MNA field is as of the Flow ID field defined in
Section 3.2 of [RFC9326].
* Sequence Number - is an optional 22-bit field. The semantics of
the Sequence Number MNA field is as of the Sequence Number field
defined in Section 3.2 of [RFC9326].
* Resv fields MUST be zeroed on transmit and ignored on receipt.
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0 1 2 3 4 5
+-+-+-+-+-+-+
|F|S|U|U|U|U|
+-+-+-+-+-+-+
Figure 2: Ext-Flags Field Format
Where fields are defined as follows:
* F - one-bit flag. When the flag is set to 1, it indicates the
presence of the Flow ID field in the IOAM-DEX-MNA header.
* S - one-bit flag. When the flag is set to 1, it indicates the
presence of the Sequence Number field in the IOAM-DEX-MNA header.
* U - unassigned one-bit flag. It MUST be zeroed on transmission
and the value MUST be ignored upon receipt.
4.2. IOAM-DEX-MNA Encoding as In-Stack Data MPLS Network Action
To support the direct export of the operational state and telemetry
information, the IOAM-DEX-MNA blob (binary large object), as shown in
Figure 1 can be placed as part of the ISD block in an MPLS label
stack according to the MNA encoding principles defined in
[I-D.ietf-mpls-mna-hdr]. Using the IHS field, the IOAM-DEX-MNA can
be performed in Hop-by-Hop, Ingress-to-Egress, or Select modes
[I-D.ietf-mpls-mna-fwk] of collecting the operational state and
telemetry information, as MNA Opcode (Figure 3). Policies
controlling the processing of the collected operational state and
telemetry information, and its transport are outside the scope of
this document.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MNA bSPL | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Opcode = TBA1 | Data |P|IHS|S| Res |U| NASL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ IOAM-DEX-MNA ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: An Example of IOAM-DEX Encapsulation as an MNA Opcode
Where the enclosed elements are defined as follows:
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* MNA bSPL is a base Special Purpose Label assigned by IANA per the
request in [I-D.ietf-mpls-mna-hdr].
* S - the Bottom of Stack field [RFC3032].
* P, IHS, Res, U, and NASL fields are as specified in Section 4.2 of
[I-D.ietf-mpls-mna-hdr].
* NASL - number of LSEs that compose the IOAM-DEX-MNA blob.
* Opcode is MNA-IOAM-DEX opcode (TBA1) assigned by IANA Section 5.1.
* IOAM-DEX-MNA - IOAM Direct Export in MPLS Network Action encoding
5. IANA Considerations
5.1. IOAM-DEX-MNA as an MPLS Network Action Opcode
IANA is requested to assign an IOAM-DEX-MNA codepoint (TBA1) from its
Network Action Opcodes registry (creation requested in
[I-D.ietf-mpls-mna-hdr]) as specified in Table 1.
+========+==========================+===============+
| Opcode | Description | Reference |
+========+==========================+===============+
| TBA1 | IOAM-DEX as MPLS Network | This document |
| | Action Indicator | |
+--------+--------------------------+---------------+
Table 1: IOAM-DEX as MPLS Network Action Opcode
6. Security Considerations
Security considerations discussed in [RFC9197], [RFC9326], and
[I-D.ietf-mpls-mna-fwk] apply to this document.
7. Acknowledgments
TBD
8. References
8.1. Normative References
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[I-D.ietf-mpls-mna-fwk]
Andersson, L., Bryant, S., Bocci, M., and T. Li, "MPLS
Network Actions Framework", Work in Progress, Internet-
Draft, draft-ietf-mpls-mna-fwk-04, 5 September 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-mpls-
mna-fwk-04>.
[I-D.ietf-mpls-mna-hdr]
Rajamanickam, J., Gandhi, R., Zigler, R., Song, H., and K.
Kompella, "MPLS Network Action (MNA) Sub-Stack Solution",
Work in Progress, Internet-Draft, draft-ietf-mpls-mna-hdr-
03, 6 September 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-mpls-
mna-hdr-03>.
[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>.
[RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y.,
Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack
Encoding", RFC 3032, DOI 10.17487/RFC3032, January 2001,
<https://www.rfc-editor.org/info/rfc3032>.
[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>.
[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>.
8.2. Informational References
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[I-D.ietf-mpls-mna-usecases]
Saad, T., Makhijani, K., Song, H., and G. Mirsky, "Use
Cases for MPLS Network Action Indicators and MPLS
Ancillary Data", Work in Progress, Internet-Draft, draft-
ietf-mpls-mna-usecases-03, 15 September 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-mpls-
mna-usecases-03>.
[IANA-IOAM-Trace-Type]
IANA, "IOAM Trace-Type",
<https://www.iana.org/assignments/ioam/ioam.xhtml#trace-
type>.
[RFC8969] Wu, Q., Ed., Boucadair, M., Ed., Lopez, D., Xie, C., and
L. Geng, "A Framework for Automating Service and Network
Management with YANG", RFC 8969, DOI 10.17487/RFC8969,
January 2021, <https://www.rfc-editor.org/info/rfc8969>.
Authors' Addresses
Greg Mirsky
Ericsson
Email: gregimirsky@gmail.com
Mohamed Boucadair
Orange
35000 Rennes
France
Email: mohamed.boucadair@orange.com
Tony Li
Juniper Networks
Email: tony.li@tony.li
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