rfc9546.original   rfc9546.txt 
DetNet Working Group G. Mirsky Internet Engineering Task Force (IETF) G. Mirsky
Internet-Draft Ericsson Request for Comments: 9546 Ericsson
Intended status: Standards Track M. Chen Category: Standards Track M. Chen
Expires: 15 July 2024 Huawei ISSN: 2070-1721 Huawei
B. Varga B. Varga
Ericsson Ericsson
12 January 2024 February 2024
Operations, Administration and Maintenance (OAM) for Deterministic Operations, Administration, and Maintenance (OAM) for Deterministic
Networks (DetNet) with MPLS Data Plane Networking (DetNet) with the MPLS Data Plane
draft-ietf-detnet-mpls-oam-15
Abstract Abstract
This document defines format and usage principles of the This document defines format and usage principles of the
Deterministic Network (DetNet) service Associated Channel over a Deterministic Networking (DetNet) service Associated Channel over a
DetNet network with the MPLS data plane. The DetNet service DetNet network with the MPLS data plane. The DetNet service
Associated Channel can be used to carry test packets of active Associated Channel can be used to carry test packets of active
Operations, Administration, and Maintenance protocols that are used Operations, Administration, and Maintenance (OAM) protocols that are
to detect DetNet failures and measure performance metrics. used to detect DetNet failures and measure performance metrics.
Status of This Memo Status of This Memo
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction
2. Conventions used in this document . . . . . . . . . . . . . . 3 2. Conventions Used in This Document
2.1. Terminology and Acronyms . . . . . . . . . . . . . . . . 3 2.1. Terminology and Acronyms
2.2. Keywords . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Key Words
3. Active OAM for DetNet Networks with MPLS Data Plane . . . . . 4 3. Active OAM for DetNet Networks with the MPLS Data Plane
3.1. DetNet Active OAM Encapsulation . . . . . . . . . . . . . 4 3.1. DetNet Active OAM Encapsulation
3.2. DetNet Packet Replication, Elimination, and Ordering 3.2. DetNet PREOF Interaction with Active OAM
Functions Interaction with Active OAM . . . . . . . . . . 7 4. OAM Interworking Models
4. OAM Interworking Models . . . . . . . . . . . . . . . . . . . 8 4.1. OAM of DetNet MPLS Interworking with OAM of TSN
4.1. OAM of DetNet MPLS Interworking with OAM of TSN . . . . . 8 4.2. OAM of DetNet MPLS Interworking with OAM of DetNet IP
4.2. OAM of DetNet MPLS Interworking with OAM of DetNet IP . . 9 5. IANA Considerations
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 5.1. DetNet Associated Channel Header (d-ACH) Flags Registry
5.1. DetNet Associated Channel Header Flags Registry . . . . . 10 6. Security Considerations
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 7. References
7. Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . 10 7.1. Normative References
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 7.2. Informative References
8.1. Normative References . . . . . . . . . . . . . . . . . . 10 Acknowledgments
8.2. Informational References . . . . . . . . . . . . . . . . 11 Authors' Addresses
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction 1. Introduction
[RFC8655] introduces and explains Deterministic Networks (DetNet) [RFC8655] introduces and explains Deterministic Networking (DetNet)
architecture and how the Packet Replication, Elimination, and architecture and how the Packet Replication, Elimination, and
Ordering functions (PREOF) can be used to ensure a low packet drop Ordering Functions (PREOF) can be used to ensure a low packet drop
ratio in a DetNet domain. ratio in a DetNet domain.
Operations, Administration, and Maintenance (OAM) protocols are used Operations, Administration, and Maintenance (OAM) protocols are used
to detect and localize network defects, and to monitor network to detect and localize network defects and to monitor network
performance. Some OAM functions (e.g., failure detection) are performance. Some OAM functions (e.g., failure detection) are
usually performed proactively in the network, while others (e.g., usually performed proactively in the network, while others (e.g.,
defect localization) are typically performed on demand. These tasks defect localization) are typically performed on demand. These tasks
can be achieved through a combination of active and hybrid OAM can be achieved through a combination of active and hybrid OAM
methods, as classified in [RFC7799]. This document presents a format methods, as classified in [RFC7799]. This document presents a format
for active OAM in DetNet networks with MPLS data plane. for active OAM in DetNet networks with the MPLS data plane.
Also, this document defines format and usage principles of the DetNet Also, this document defines format and usage principles of the DetNet
service Associated Channel over a DetNet network with the MPLS data service Associated Channel over a DetNet network with the MPLS data
plane [RFC8964]. plane [RFC8964].
2. Conventions used in this document 2. Conventions Used in This Document
2.1. Terminology and Acronyms 2.1. Terminology and Acronyms
The term "DetNet OAM" is used in this document interchangeably with The term "DetNet OAM" in this document is used interchangeably with a
longer version "set of OAM protocols, methods and tools for "set of OAM protocols, methods, and tools for Deterministic
Deterministic Networks". Networking".
DetNet Deterministic Network BFD: Bidirectional Forwarding Detection
d-ACH DetNet Associated Channel Header CFM: Connectivity Fault Management
OAM Operations, Administration, and Maintenance d-ACH: DetNet Associated Channel Header
PREOF Packet Replication, Elimination, and Ordering Functions DetNet: Deterministic Networking
PW Pseudowire DetNet Node: A node that is an actor in the DetNet domain. Examples
of DetNet nodes include DetNet domain edge nodes and DetNet nodes
that perform PREOF within the DetNet domain.
E2E End-to-end E2E: End to end
BFD Bidirectional Forwarding Detection F-Label: A DetNet "forwarding" label. The F-Label identifies the
Label Switched Path (LSP) used to forward a DetNet flow across an
MPLS Packet Switched Network (PSN), e.g., a hop-by-hop label used
between label switching routers.
TSN IEEE 802.1 Time-Sensitive Networking OAM: Operations, Administration, and Maintenance
CFM Connectivity Fault Management PREOF: Packet Replication, Elimination, and Ordering Functions
F-Label - a DetNet "forwarding" label. The F-Label identifies the PW: Pseudowire
LSP used to forward a DetNet flow across an MPLS PSN, e.g., a hop-by-
hop label used between label switching routers.
S-Label - a DetNet "service" label. An S-Label is used between S-Label: A DetNet "service" label. An S-Label is used between
DetNet nodes that implement the DetNet service sub-layer functions. DetNet nodes that implement the DetNet service sub-layer
An S-Label is also used to identify a DetNet flow at DetNet service functions. An S-Label is also used to identify a DetNet flow at
sub-layer. the DetNet service sub-layer.
Underlay Network or Underlay Layer - the network that provides TSN: Time-Sensitive Networking
connectivity between the DetNet nodes. One example of an underlay
layer is an MPLS network that provides Label Switched Path (LSP)
connectivity between DetNet nodes.
DetNet Node - a node that is an actor in the DetNet domain. Examples Underlay Network or Underlay Layer: The network that provides
of DetNet nodes include DetNet domain Edge nodes, and DetNet nodes connectivity between the DetNet nodes. One example of an underlay
that perform PREOF within the DetNet domain. layer is an MPLS network that provides LSP connectivity between
DetNet nodes.
2.2. Keywords 2.2. Key Words
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in
14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
3. Active OAM for DetNet Networks with MPLS Data Plane 3. Active OAM for DetNet Networks with the MPLS Data Plane
OAM protocols and mechanisms act within the data plane of the OAM protocols and mechanisms act within the data plane of the
particular networking layer, thus it is critical that the data plane particular networking layer; thus, it is critical that the data plane
encapsulation supports OAM mechanisms that comply with the OAM encapsulation supports OAM mechanisms that comply with the OAM
requirements listed in [I-D.ietf-detnet-oam-framework]. requirements listed in [OAM-FRAMEWORK].
Operation of a DetNet data plane with an MPLS underlay network is Operation of a DetNet data plane with an MPLS underlay network is
specified in [RFC8964]. Within the MPLS underlay network, DetNet specified in [RFC8964]. Within the MPLS underlay network, DetNet
flows are to be encapsulated analogous to pseudowires as specified in flows are to be encapsulated analogous to pseudowires (PWs) as
[RFC3985], [RFC4385]. For reference, the Generic Pseudowire (PW) specified in [RFC3985] and [RFC4385]. For reference, the Generic PW
MPLS Control Word (as defined in [RFC4385] and used with DetNet) is MPLS Control Word (as defined in [RFC4385] and used with DetNet) is
reproduced in Figure 1. reproduced in Figure 1.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0| Sequence Number | |0 0 0 0| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: DetNet Control Word Format Figure 1: Generic PW MPLS Control Word Format
PREOF in the DetNet domain is composed of a combination of nodes that PREOF in the DetNet domain is composed of a combination of nodes that
perform replication and elimination functions. The Elimination sub- perform replication and elimination functions. The Elimination sub-
function always uses the S-Label in conjunction with the packet function always uses the S-Label in conjunction with the packet
sequencing information (i.e., the Sequence Number encoded in the sequencing information (i.e., the Sequence Number encoded in the
DetNet Control Word). The Replication sub-function uses the S-Label DetNet Control Word). The Replication sub-function uses the S-Label
information only. information only.
3.1. DetNet Active OAM Encapsulation 3.1. DetNet Active OAM Encapsulation
DetNet OAM, like PW OAM, uses the PW Associated Channel Header DetNet OAM, like PW OAM, uses the PW Associated Channel Header
defined in [RFC4385]. At the same time, a DetNet PW can be viewed as defined in [RFC4385]. At the same time, a DetNet PW can be viewed as
a Multi-Segment PW, where DetNet service sub-layer functions are at a Multi-Segment PW, where DetNet service sub-layer functions are at
the segment endpoints. However, DetNet service sub-layer functions the segment endpoints. However, DetNet service sub-layer functions
operate per packet level (not per segment). These per-packet level operate per packet level (not per segment). These per-packet level
characteristics of PREOF require additional fields for proper OAM characteristics of PREOF require additional fields for proper OAM
packet processing. Encapsulation of a DetNet MPLS [RFC8964] active packet processing. MPLS encapsulation [RFC8964] of a DetNet active
OAM packet is shown in Figure 2. OAM packet is shown in Figure 2.
+---------------------------------+ +---------------------------------+
| | | |
| DetNet OAM Packet | | DetNet OAM Packet |
| | | |
+---------------------------------+ <--\ +---------------------------------+ <--\
| DetNet Associated Channel Header| | | DetNet Associated Channel Header| |
+---------------------------------+ +--> DetNet active OAM +---------------------------------+ +--> DetNet active OAM
| S-Label | | MPLS encapsulation | S-Label | | MPLS encapsulation
+---------------------------------+ | +---------------------------------+ |
| [ F-Label(s) ] | | | [ F-Label(s) ] | |
+---------------------------------+ <--/ +---------------------------------+ <--/
| Data-Link | | Data-Link |
+---------------------------------+ +---------------------------------+
| Physical | | Physical |
+---------------------------------+ +---------------------------------+
Figure 2: DetNet Active OAM Packet Encapsulation in MPLS Data Plane Figure 2: DetNet Active OAM Packet Encapsulation in the MPLS Data
Plane
Figure 3 displays encapsulation of a test packet of an active DetNet Figure 3 displays encapsulation of a test packet for a DetNet active
OAM protocol in case of MPLS-over-UDP/IP [RFC9025]. OAM protocol in case of MPLS over UDP/IP [RFC9025].
+---------------------------------+ +---------------------------------+
| | | |
| DetNet OAM Packet | | DetNet OAM Packet |
| | | |
+---------------------------------+ <--\ +---------------------------------+ <--\
| DetNet Associated Channel Header| | | DetNet Associated Channel Header| |
+---------------------------------+ +--> DetNet active OAM +---------------------------------+ +--> DetNet active OAM
| S-Label | | MPLS encapsulation | S-Label | | MPLS encapsulation
+---------------------------------+ | +---------------------------------+ |
skipping to change at page 5, line 47 skipping to change at line 227
+---------------------------------+ <--+ +---------------------------------+ <--+
| UDP Header | | | UDP Header | |
+---------------------------------+ +--> DetNet data plane +---------------------------------+ +--> DetNet data plane
| IP Header | | IP encapsulation | IP Header | | IP encapsulation
+---------------------------------+ <--/ +---------------------------------+ <--/
| Data-Link | | Data-Link |
+---------------------------------+ +---------------------------------+
| Physical | | Physical |
+---------------------------------+ +---------------------------------+
Figure 3: DetNet Active OAM Packet Encapsulation in MPLS-over-UDP/IP Figure 3: DetNet Active OAM Packet Encapsulation in MPLS over UDP/IP
Figure 4 displays the format of the DetNet Associated Channel Header Figure 4 displays the format of the DetNet Associated Channel Header
(d-ACH). (d-ACH).
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|Version|Sequence Number| Channel Type | |0 0 0 1|Version|Sequence Number| Channel Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Node ID |Level| Flags |Session| | Node ID |Level| Flags |Session|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: d-ACH Format Figure 4: d-ACH Format
The d-ACH encodes the following fields: The d-ACH encodes the following fields:
Bits 0..3: These MUST be 0b0001. This allows the packet to be
distinguished from an IP packet [RFC4928] and from a DetNet
data packet [RFC8964].
Bits 0..3 MUST be 0b0001. This allows the packet to be Version: A 4-bit field. This document specifies version 0.
distinguished from an IP packet [RFC4928] and from a DetNet data
packet [RFC8964].
Version - a 4-bit field. This document specifies version 0.
Sequence Number - is an unsigned circular 8-bit field. Because a Sequence Number: An unsigned circular 8-bit field. Because a
test packet of DetNet active OAM includes d-ACH, Section 4.2.1 of DetNet active OAM test packet includes d-ACH, Section 4.2.1 of
[RFC8964] does not apply to handling the Sequence Number field in [RFC8964] does not apply to handling the Sequence Number field
DetNet OAM over the MPLS data plane. The sequence number space is in DetNet OAM over the MPLS data plane. The sequence number
circular with no restriction on the initial value. The originator space is circular with no restriction on the initial value.
DetNet node MUST set the value of the Sequence Number field before The originator DetNet node MUST set the value of the Sequence
the transmission of a packet. the initial value SHOULD be random Number field before the transmission of a packet. The initial
(unpredictable). The originator node SHOULD increase the value of value SHOULD be random (unpredictable). The originator node
the Sequence Number field by 1 for each active OAM packet. The SHOULD increase the value of the Sequence Number field by 1 for
originator MAY use other strategies, e.g., for negative testing of each active OAM packet. The originator MAY use other
Packet Ordering Functions. strategies, e.g., for negative testing of Packet Ordering
Functions.
Channel Type - is a 16-bit field, and the value of DetNet Channel Type: A 16-bit field and the value of the DetNet
Associated Channel Type. It MUST be one of the values listed in Associated Channel Type. It MUST be one of the values listed
the IANA MPLS Generalized Associated Channel Types (including in the IANA "MPLS Generalized Associated Channel (G-ACh) Types
Pseudowire Associated Channel Types) registry [IANA-G-ACh-Types]. (including Pseudowire Associated Channel Types)" registry
[IANA-G-ACh-Types].
Node ID - is an unsigned 20-bit field. The value of the Node ID Node ID: An unsigned 20-bit field. The value of the Node ID
field identifies the DetNet node that originated the packet. A field identifies the DetNet node that originated the packet. A
DetNet node MUST be provisioned with a Node ID that is unique in DetNet node MUST be provisioned with a Node ID that is unique
the DetNet domain. Methods of distributing Node ID are outside in the DetNet domain. Methods for distributing Node ID are
the scope of this specification. outside the scope of this specification.
Level - is a 3-bit field. Semantically, the Level field is Level: A 3-bit field. Semantically, the Level field is analogous
anlogous to the Maintenance Domain Level in [IEEE.802.1Q]. The to the Maintenance Domain Level in [IEEE.802.1Q]. The Level
Level field is used to cope with the "all active path forwarding" field is used to cope with the "all active path forwarding"
(defined by the TSN Task Group of the IEEE 802.1 WG (defined by the TSN Task Group of the IEEE 802.1 WG
[IEEE802.1TSNTG]) characteristics of the PREOF concept. A [IEEE802.1TSNTG]) characteristics of the PREOF concept. A
hierarchical relationship between OAM domains can be created using hierarchical relationship between OAM domains can be created
the Level field value, illustrated by Figure 18.7 in using the Level field value, as illustrated by Figure 18.7 in
[IEEE.802.1Q]. [IEEE.802.1Q].
Flags - is a 5-bit field. The Flags field contains five 1-bit Flags: A 5-bit field. The Flags field contains five 1-bit flags.
flags. Section 5.1 creates the IANA d-ACH Flags registry for new Section 5.1 creates the IANA "DetNet Associated Channel Header
flags to be defined. The flags defined in this specification are (d-ACH) Flags" registry for new flags to be defined. The flags
presented in Figure 5. defined in this specification are presented in Figure 5.
0 1 2 3 4 Session ID: A 4-bit field. The Session field distinguishes OAM
+-+-+-+-+-+ sessions originating from the same node (a given Maintenance
|U|U|U|U|U| End Point may have multiple simultaneously active OAM sessions)
+-+-+-+-+-+ at the given Level.
Figure 5: DetNet Associated Channel Header Flags Field Format 0 1 2 3 4
+-+-+-+-+-+
|U|U|U|U|U|
+-+-+-+-+-+
U: Unused and for future use. MUST be 0 on transmission and ignored Figure 5: DetNet Associated Channel Header Flags Field Format
on receipt.
Session ID is a 4-bit field. The Session field distinguishes OAM U: Unused and for future use. MUST be 0 on transmission and ignored
sessions originating from the same node (a given Maintenance End on receipt.
Point may have multiple simultaneously active OAM sessions) at the
given Level.
A DetNet flow, according to [RFC8964], is identified by the S-Label According to [RFC8964], a DetNet flow is identified by the S-Label
that MUST be at the bottom of the stack. An Active OAM packet MUST that MUST be at the bottom of the stack. An active OAM packet MUST
include d-ACH immediately following the S-Label. include d-ACH immediately following the S-Label.
3.2. DetNet Packet Replication, Elimination, and Ordering Functions 3.2. DetNet PREOF Interaction with Active OAM
Interaction with Active OAM
At the DetNet service sub-layer, special functions (notably PREOF) At the DetNet service sub-layer, special functions (notably PREOF)
MAY be applied to the particular DetNet flow to potentially reduce MAY be applied to the particular DetNet flow to potentially reduce
packet loss, improve the probability of on-time packet delivery, and packet loss, improve the probability of on-time packet delivery, and
ensure in-order packet delivery. PREOF relies on sequencing ensure in-order packet delivery. PREOF relies on sequencing
information in the DetNet service sub-layer. For a DetNet active OAM information in the DetNet service sub-layer. For a DetNet active OAM
packet, PREOF MUST use the Sequence Number field value as the source packet, PREOF MUST use the Sequence Number field value as the source
of this sequencing information. App-flow and OAM use different of this sequencing information. App-flow and OAM use different
sequence number spaces. PREOF algorithms are executed with respect sequence number spaces. PREOF algorithms are executed with respect
to the sequence number space identified by the flow's characteristic to the sequence number space identified by the flow's characteristic
information. Although the Sequence Number field in d-ACH has a range information. Although the Sequence Number field in d-ACH has a range
from 0 through 255, it provides sufficient space because the rate of from 0 through 255, it provides sufficient space because the rate of
DetNet active OAM packet is significantly lower compared to the rate DetNet active OAM packets is significantly lower compared to the rate
of DetNet packets in an App-flow; therefore, wrapping around is not of DetNet packets in an App-flow; therefore, wrapping around is not
an issue. an issue.
4. OAM Interworking Models 4. OAM Interworking Models
Interworking of two OAM domains that utilize different networking Interworking of two OAM domains that utilize different networking
technology can be realized either by a peering or a tunneling model. technology can be realized by either a peering model or a tunneling
In a peering model, OAM domains are within the corresponding network model. In a peering model, OAM domains are within the corresponding
domain. When using the peering model, state changes that are network domain. When using the peering model, state changes that are
detected by a Fault Management OAM protocol can be mapped from one detected by a Fault Management OAM protocol can be mapped from one
OAM domain into another or a notification, e.g., an alarm, can be OAM domain into another or a notification, e.g., an alarm can be sent
sent to a central controller. In the tunneling model of OAM to a central controller. In the tunneling model of OAM interworking,
interworking, usually, only one active OAM protocol is used. Its usually only one active OAM protocol is used. Its test packets are
test packets are tunneled through another domain along with the data tunneled through another domain along with the data flow, thus
flow, thus ensuring the fate sharing among test and data packets. ensuring fate sharing among test and data packets.
4.1. OAM of DetNet MPLS Interworking with OAM of TSN 4.1. OAM of DetNet MPLS Interworking with OAM of TSN
Active DetNet OAM can provide the end-to-end (E2E) fault management DetNet active OAM can provide end-to-end (E2E) fault management and
and performance monitoring for a DetNet flow. In the case of DetNet performance monitoring for a DetNet flow. In the case of DetNet with
with an MPLS data plane and an IEEE 802.1 Time-Sensitive Networking an MPLS data plane and an IEEE 802.1 Time-Sensitive Networking (TSN)
(TSN) sub-network, this implies the interworking of DetNet active OAM sub-network, it implies the interworking of DetNet active OAM with
with TSN OAM, which data plane aspects are specified in [RFC9037]. TSN OAM, of which the data plane aspects are specified in [RFC9037].
When the peering model (Section 4) is used in Connectivity Fault When the peering model (Section 4) is used in the Connectivity Fault
Management (CFM) OAM protocol [IEEE.802.1Q], then the node that Management (CFM) OAM protocol [IEEE.802.1Q], the node that borders
borders both TSN and DetNet MPLS domains MUST support [RFC7023]. both TSN and DetNet MPLS domains MUST support [RFC7023]. [RFC7023]
[RFC7023] specifies the mapping of defect states between Ethernet specifies the mapping of defect states between Ethernet Attachment
Attachment Circuits and associated Ethernet PWs that are part of an Circuits and associated Ethernet PWs that are part of an E2E emulated
E2E emulated Ethernet service, and are also applicable to E2E OAM Ethernet service and are also applicable to E2E OAM across DetNet
across DetNet MPLS and TSN domains. The CFM [IEEE.802.1Q] or in MPLS and TSN domains. The CFM [IEEE.802.1Q] [ITU.Y1731] can provide
[ITU.Y1731] can provide fast detection of a failure in the TSN fast detection of a failure in the TSN segment of the DetNet service.
segment of the DetNet service. In the DetNet MPLS domain BFD In the DetNet MPLS domain, Bidirectional Forwarding Detection (BFD),
(Bidirectional Forwarding Detection), specified in [RFC5880] and as specified in [RFC5880] and [RFC5885], can be used. To provide E2E
[RFC5885], can be used. To provide E2E failure detection, the TSN failure detection, the TSN and DetNet MPLS segments could be treated
and DetNet MPLS segments could be treated as concatenated such that as concatenated such that the diagnostic codes (see Section 6.8.17 of
the diagnostic codes (see Section 6.8.17 of [RFC5880]) MAY be used to [RFC5880]) MAY be used to inform the upstream DetNet MPLS node of a
inform the upstream DetNet MPLS node of a failure of the TSN segment. TSN segment failure. Performance monitoring can be supported by
Performance monitoring can be supported by [RFC6374] in the DetNet [RFC6374] in the DetNet MPLS and by [ITU.Y1731] in TSN domains,
MPLS and [ITU.Y1731] in the TSN domains, respectively. Performance respectively. Performance objectives for each domain should refer to
objectives for each domain should refer to metrics that is composable metrics that are composable [RFC6049] or are defined for each domain
[RFC6049] or be defined for each domain separately. separately.
The following considerations apply when using the tunneling model of The following considerations apply when using the tunneling model of
OAM interworking between DetNet MPLS and TSN domains based on general OAM interworking between DetNet MPLS and TSN domains based on general
principles described in Section 4 of [RFC9037]: principles described in Section 4 of [RFC9037]:
* Active OAM test packets MUST be mapped to the same TSN Stream ID * Active OAM test packets MUST be mapped to the same TSN Stream ID
as the monitored DetNet flow. as the monitored DetNet flow.
* Active OAM test packets MUST be treated in the TSN domain based on * Active OAM test packets MUST be processed in the TSN domain based
its S-Label and Class of Service marking (the Traffic Class field on their S-Label and Class of Service marking (the Traffic Class
value). field value).
Mapping between a DetNet flow and TSN Stream in the TSN sub-network Mapping between a DetNet flow and TSN Stream in the TSN sub-network
is described in Section 4.1 of [RFC9037]. The mapping has to be done is described in Section 4.1 of [RFC9037]. The mapping has to be done
only on the edge node of the TSN sub-network, and intermediate TSN only on the edge node of the TSN sub-network, and intermediate TSN
nodes do not need to recognize the S-Label. An edge node has two nodes do not need to recognize the S-Label. An edge node has two
components: components:
1. A passive Stream identification function. 1. A passive Stream identification function.
2. An active Stream identification function. 2. An active Stream identification function.
The first component identifies the DetNet flow (using Clause 6.8 of The first component identifies the DetNet flow (using Clause 6.8 of
[IEEE.802.1CBdb]), and the second component creates the TSN Stream by [IEEE.802.1CBdb]), and the second component creates the TSN Stream by
manipulating the Ethernet header. That manipulation simplifies the manipulating the Ethernet header. That manipulation simplifies the
identification of the TSN Stream in the intermediate TSN nodes by identification of the TSN Stream in the intermediate TSN nodes by
avoiding the need for them to look outside of the Ethernet header. avoiding the need for them to look outside of the Ethernet header.
DetNet MPLS OAM packets use the same S-Label as the DetNet flow data DetNet MPLS OAM packets use the same S-Label as the DetNet flow data
packets. The above-described mapping function treats these OAM packets. The above-described mapping function treats these OAM
packets as data packets of the DetNet flow. As a result, DetNet MPLS packets as data packets of the DetNet flow. As a result, DetNet MPLS
OAM packets are fate-sharing within the TSN sub-network. As an OAM packets are fate sharing within the TSN sub-network. As an
example of the mapping between DetNet MPLS and TSN, see Annex C.1 of example of the mapping between DetNet MPLS and TSN, see Annex C.1 of
[IEEE.802.1CBdb] that, in support of [RFC9037], describes how to [IEEE.802.1CBdb] that, in support of [RFC9037], describes how to
match MPLS DetNet flows and TSN Streams can be achieved. match MPLS DetNet flows and achieve TSN Streams.
Note that the tunneling model of the OAM interworking requires that Note that the tunneling model of the OAM interworking requires that
the remote peer of the E2E OAM domain supports the active OAM the remote peer of the E2E OAM domain supports the active OAM
protocol selected on the ingress endpoint. For example, if BFD is protocol selected on the ingress endpoint. For example, if BFD is
used for proactive path continuity monitoring in the DetNet MPLS used for proactive path continuity monitoring in the DetNet MPLS
domain, BFD support (as defined in [RFC5885]) is necessary at any TSN domain, BFD support (as defined in [RFC5885]) is necessary at any TSN
endpoint of the DetNet service. endpoint of the DetNet service.
4.2. OAM of DetNet MPLS Interworking with OAM of DetNet IP 4.2. OAM of DetNet MPLS Interworking with OAM of DetNet IP
Interworking between active OAM segments in DetNet MPLS and DetNet IP Interworking between active OAM segments in DetNet MPLS and DetNet IP
domains can also be realized using either the peering or the domains can also be realized using either the peering model or the
tunneling model, as discussed in Section 4.1. Using the same tunneling model, as discussed in Section 4.1. Using the same
protocol, e.g., BFD, over both segments, simplifies the mapping of protocol, e.g., BFD over both segments, simplifies the mapping of
errors in the peering model. For example, respective BFD sessions in errors in the peering model. For example, respective BFD sessions in
DetNet MPLS and DetNet IP domains can be in a concatenated DetNet MPLS and DetNet IP domains can be in a concatenated
relationship as described in Section 6.8.17 of [RFC5880]. To provide relationship as described in Section 6.8.17 of [RFC5880]. To provide
performance monitoring over a DetNet IP domain, STAMP [RFC8762] and performance monitoring over a DetNet IP domain, the Simple Two-way
its extensions [RFC8972] can be used to measure packet loss and Active Measurement Protocol (STAMP) [RFC8762] and its extensions
packet delay metrics. Such performance metrics can be used to [RFC8972] can be used to measure packet loss and packet delay
calculate composable metrics [RFC6049] within DetNet MPLS and DetNet metrics. Such performance metrics can be used to calculate
IP domains to reflect the end-to-end DetNet service performance. composable metrics [RFC6049] within DetNet MPLS and DetNet IP domains
to reflect the end-to-end DetNet service performance.
5. IANA Considerations 5. IANA Considerations
5.1. DetNet Associated Channel Header Flags Registry 5.1. DetNet Associated Channel Header (d-ACH) Flags Registry
This document describes a new IANA-managed registry to identify d-ACH IANA has created the "DetNet Associated Channel Header (d-ACH) Flags"
Flags bits. The registration procedure is "IETF Review" [RFC8126]. registry within the "DetNet Associated Channel Header (d-ACH) Flags"
The registry name is "DetNet Associated Channel Header (d-ACH) registry group. The registration procedure is "IETF Review"
Flags". IANA should treat "DetNet Associated Channel Header (d-ACH) [RFC8126]. There are five flags in the 5-bit Flags field, as defined
Flags" as the name of the registry group. There are five flags in in Table 1.
the five-bit Flags field, defined as in Table 1.
+=====+=============+===============+ +=====+=============+
| Bit | Description | Reference | | Bit | Description |
+=====+=============+===============+ +=====+=============+
| 0-4 | Unassigned | This document | | 0-4 | Unassigned |
+-----+-------------+---------------+ +-----+-------------+
Table 1: DetNet Associated Table 1: DetNet
Channel Header (d-ACH) Flags Associated Channel
Header (d-ACH) Flags
Registry
6. Security Considerations 6. Security Considerations
Security considerations discussed in DetNet specifications [RFC8655], Security considerations discussed in DetNet specifications [RFC8655],
[RFC9055], [RFC8964], and [I-D.ietf-detnet-oam-framework] are [RFC8964], [RFC9055], and [OAM-FRAMEWORK] are applicable to this
applicable to this document. Security concerns and issues related to document. Security concerns and issues related to MPLS OAM tools
MPLS OAM tools like LSP Ping [RFC8029], and BFD over PW [RFC5885] like LSP Ping [RFC8029] and BFD over PW [RFC5885] also apply to this
also apply to this specification. specification.
7. Acknowledgment
Authors extend their appreciation to Pascal Thubert for his
insightful comments and productive discussion that helped to improve
the document. The authors are enormously grateful to Janos Farkas
for his detailed comments and the inspiring discussion that made this
document clearer and stronger. The authors recognize helpful reviews
and suggestions from Andrew Malis, David Black, Tianran Zhou, and
Kiran Makhijani. And special thanks are addressed to Ethan Grossman
for his fantastic help in improving the document.
8. References 7. References
8.1. Normative References 7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC7023] Mohan, D., Ed., Bitar, N., Ed., Sajassi, A., Ed., DeLord, [RFC7023] Mohan, D., Ed., Bitar, N., Ed., Sajassi, A., Ed., DeLord,
S., Niger, P., and R. Qiu, "MPLS and Ethernet Operations, S., Niger, P., and R. Qiu, "MPLS and Ethernet Operations,
Administration, and Maintenance (OAM) Interworking", Administration, and Maintenance (OAM) Interworking",
RFC 7023, DOI 10.17487/RFC7023, October 2013, RFC 7023, DOI 10.17487/RFC7023, October 2013,
skipping to change at page 11, line 35 skipping to change at line 484
[RFC8964] Varga, B., Ed., Farkas, J., Berger, L., Malis, A., Bryant, [RFC8964] Varga, B., Ed., Farkas, J., Berger, L., Malis, A., Bryant,
S., and J. Korhonen, "Deterministic Networking (DetNet) S., and J. Korhonen, "Deterministic Networking (DetNet)
Data Plane: MPLS", RFC 8964, DOI 10.17487/RFC8964, January Data Plane: MPLS", RFC 8964, DOI 10.17487/RFC8964, January
2021, <https://www.rfc-editor.org/info/rfc8964>. 2021, <https://www.rfc-editor.org/info/rfc8964>.
[RFC9025] Varga, B., Ed., Farkas, J., Berger, L., Malis, A., and S. [RFC9025] Varga, B., Ed., Farkas, J., Berger, L., Malis, A., and S.
Bryant, "Deterministic Networking (DetNet) Data Plane: Bryant, "Deterministic Networking (DetNet) Data Plane:
MPLS over UDP/IP", RFC 9025, DOI 10.17487/RFC9025, April MPLS over UDP/IP", RFC 9025, DOI 10.17487/RFC9025, April
2021, <https://www.rfc-editor.org/info/rfc9025>. 2021, <https://www.rfc-editor.org/info/rfc9025>.
8.2. Informational References 7.2. Informative References
[I-D.ietf-detnet-oam-framework]
Mirsky, G., Theoleyre, F., Papadopoulos, G. Z., Bernardos,
C. J., Varga, B., and J. Farkas, "Framework of Operations,
Administration and Maintenance (OAM) for Deterministic
Networking (DetNet)", Work in Progress, Internet-Draft,
draft-ietf-detnet-oam-framework-11, 8 January 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-detnet-
oam-framework-11>.
[IANA-G-ACh-Types] [IANA-G-ACh-Types]
IANA, "MPLS Generalized Associated Channel (G-ACh) Types IANA, "MPLS Generalized Associated Channel (G-ACh) Types
(including Pseudowire Associated Channel Types)", (including Pseudowire Associated Channel Types)",
<https://www.iana.org/assignments/g-ach-parameters/g-ach- <https://www.iana.org/assignments/g-ach-parameters/>.
parameters.xhtml#mpls-g-ach-types>.
[IEEE.802.1CBdb] [IEEE.802.1CBdb]
IEEE, "IEEE Standard for Local and metropolitan area IEEE, "IEEE Standard for Local and metropolitan area
networks--Frame Replication and Elimination for networks--Frame Replication and Elimination for
Reliability Amendment 2: Extended Stream Identification Reliability--Amendment 2: Extended Stream Identification
Functions", IEEE 802.1CBdb, 2021. Functions", IEEE Std 802.1CBdb-2021, December 2021.
[IEEE.802.1Q] [IEEE.802.1Q]
IEEE, "Bridges and Bridged Networks", IEEE 802.1Q, 2014. IEEE, "IEEE Standard for Local and Metropolitan Area
Network--Bridges and Bridged Networks", IEEE Std 802.1Q-
2018, DOI 10.1109/IEEESTD.2018.8403927, July 2018,
<https://doi.org/10.1109/IEEESTD.2018.8403927>.
[IEEE802.1TSNTG] [IEEE802.1TSNTG]
IEEE, "Time-Sensitive Networking (TSN) Task Group", IEEE 802.1, "Time-Sensitive Networking (TSN) Task Group",
IEEE 802.1Q, <https://1.ieee802.org/tsn/>. TSN Standards, <https://1.ieee802.org/tsn/>.
[ITU.Y1731] [ITU.Y1731]
ITU-T, "OAM functions and mechanisms for Ethernet based ITU-T, "Operation, administration and maintenance (OAM)
Networks", ITU-T Recommendation G.8013/Y.1731, November functions and mechanisms for Ethernet-based networks",
2013. ITU-T Recommendation G.8013/Y.1731, June 2023.
[OAM-FRAMEWORK]
Mirsky, G., Theoleyre, F., Papadopoulos, G. Z., Bernardos,
CJ., Varga, B., and J. Farkas, "Framework of Operations,
Administration and Maintenance (OAM) for Deterministic
Networking (DetNet)", Work in Progress, Internet-Draft,
draft-ietf-detnet-oam-framework-11, 8 January 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-detnet-
oam-framework-11>.
[RFC3985] Bryant, S., Ed. and P. Pate, Ed., "Pseudo Wire Emulation [RFC3985] Bryant, S., Ed. and P. Pate, Ed., "Pseudo Wire Emulation
Edge-to-Edge (PWE3) Architecture", RFC 3985, Edge-to-Edge (PWE3) Architecture", RFC 3985,
DOI 10.17487/RFC3985, March 2005, DOI 10.17487/RFC3985, March 2005,
<https://www.rfc-editor.org/info/rfc3985>. <https://www.rfc-editor.org/info/rfc3985>.
[RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson, [RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson,
"Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for "Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for
Use over an MPLS PSN", RFC 4385, DOI 10.17487/RFC4385, Use over an MPLS PSN", RFC 4385, DOI 10.17487/RFC4385,
February 2006, <https://www.rfc-editor.org/info/rfc4385>. February 2006, <https://www.rfc-editor.org/info/rfc4385>.
skipping to change at page 13, line 47 skipping to change at line 592
"Deterministic Networking (DetNet) Data Plane: MPLS over "Deterministic Networking (DetNet) Data Plane: MPLS over
IEEE 802.1 Time-Sensitive Networking (TSN)", RFC 9037, IEEE 802.1 Time-Sensitive Networking (TSN)", RFC 9037,
DOI 10.17487/RFC9037, June 2021, DOI 10.17487/RFC9037, June 2021,
<https://www.rfc-editor.org/info/rfc9037>. <https://www.rfc-editor.org/info/rfc9037>.
[RFC9055] Grossman, E., Ed., Mizrahi, T., and A. Hacker, [RFC9055] Grossman, E., Ed., Mizrahi, T., and A. Hacker,
"Deterministic Networking (DetNet) Security "Deterministic Networking (DetNet) Security
Considerations", RFC 9055, DOI 10.17487/RFC9055, June Considerations", RFC 9055, DOI 10.17487/RFC9055, June
2021, <https://www.rfc-editor.org/info/rfc9055>. 2021, <https://www.rfc-editor.org/info/rfc9055>.
Acknowledgments
The authors extend their appreciation to Pascal Thubert for his
insightful comments and productive discussion that helped to improve
the document. The authors are enormously grateful to János Farkas
for his detailed comments and the inspiring discussion that made this
document clearer and stronger. The authors recognize helpful reviews
and suggestions from Andrew Malis, David Black, Tianran Zhou, and
Kiran Makhijani. And special thanks to Ethan Grossman for his
fantastic help in improving the document.
Authors' Addresses Authors' Addresses
Greg Mirsky Greg Mirsky
Ericsson Ericsson
Email: gregimirsky@gmail.com Email: gregimirsky@gmail.com
Mach(Guoyi) Chen Mach(Guoyi) Chen
Huawei Huawei
Email: mach.chen@huawei.com Email: mach.chen@huawei.com
Balazs Varga Balazs Varga
Ericsson Ericsson
Budapest Budapest
Magyar Tudosok krt. 11. Magyar Tudosok krt. 11.
1117 1117
Hungary Hungary
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