DetNet B. Varga, Ed.
Internet-Draft J. Farkas
Intended status: Standards Track Ericsson
Expires: April 14, 2021 L. Berger
LabN Consulting, L.L.C.
A. Malis
Malis Consulting
S. Bryant
Futurewei Technologies
J. Korhonen
October 11, 2020
DetNet Data Plane: MPLS
draft-ietf-detnet-mpls-13
Abstract
This document specifies the Deterministic Networking data plane when
operating over an MPLS Packet Switched Network. It leverages
existing pseudowire (PW) encapsulations and MPLS Traffic Engineering
encapsulations and mechanisms. This document builds on the DetNet
Architecture and Data Plane Framework.
Status of This Memo
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provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on April 14, 2021.
Copyright Notice
Copyright (c) 2020 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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Terms Used in This Document . . . . . . . . . . . . . . . 4
2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4
2.3. Requirements Language . . . . . . . . . . . . . . . . . . 5
3. DetNet MPLS Data Plane Overview . . . . . . . . . . . . . . . 5
3.1. Layers of DetNet Data Plane . . . . . . . . . . . . . . . 5
3.2. DetNet MPLS Data Plane Scenarios . . . . . . . . . . . . 6
4. MPLS-Based DetNet Data Plane Solution . . . . . . . . . . . . 8
4.1. DetNet Over MPLS Encapsulation Components . . . . . . . . 8
4.2. MPLS Data Plane Encapsulation . . . . . . . . . . . . . . 9
4.2.1. DetNet Control Word and the DetNet Sequence Number . 10
4.2.2. S-Labels . . . . . . . . . . . . . . . . . . . . . . 12
4.2.3. F-Labels . . . . . . . . . . . . . . . . . . . . . . 15
4.3. OAM Indication . . . . . . . . . . . . . . . . . . . . . 17
4.4. Flow Aggregation . . . . . . . . . . . . . . . . . . . . 18
4.4.1. Aggregation Via LSP Hierarchy . . . . . . . . . . . . 18
4.4.2. Aggregating DetNet Flows as a new DetNet flow . . . . 19
4.5. Service Sub-Layer Considerations . . . . . . . . . . . . 20
4.5.1. Edge Node Processing . . . . . . . . . . . . . . . . 20
4.5.2. Relay Node Processing . . . . . . . . . . . . . . . . 20
4.6. Forwarding Sub-Layer Considerations . . . . . . . . . . . 21
4.6.1. Class of Service . . . . . . . . . . . . . . . . . . 21
4.6.2. Quality of Service . . . . . . . . . . . . . . . . . 21
5. Management and Control Information Summary . . . . . . . . . 22
5.1. Service Sub-Layer Information Summary . . . . . . . . . . 23
5.1.1. Service Aggregation Information Summary . . . . . . . 24
5.2. Forwarding Sub-Layer Information Summary . . . . . . . . 24
6. Security Considerations . . . . . . . . . . . . . . . . . . . 25
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 26
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 26
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
10.1. Normative References . . . . . . . . . . . . . . . . . . 27
10.2. Informative References . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31
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1. Introduction
Deterministic Networking (DetNet) is a service that can be offered by
a network to DetNet flows. DetNet provides a capability for the
delivery of data flows with extremely low packet loss rates and
bounded end-to-end delivery latency. General background and concepts
of DetNet can be found in the DetNet Architecture [RFC8655].
The purpose of this document is to describe the use of the MPLS data
plane to establish and support DetNet flows. The DetNet Architecture
models the DetNet related data plane functions decomposed into two
sub-layers: a service sub-layer and a forwarding sub-layer. The
service sub-layer is used to provide DetNet service functions such as
protection and reordering. At the DetNet data plane a new set of
functions (PREOF) provide the service sub-layer specific tasks. The
forwarding sub-layer is used to provide forwarding assurance (low
loss, assured latency, and limited out-of-order delivery). The use
of the functionalities of the DetNet service sub-layer and the DetNet
forwarding sub-layer require careful design and control by the
controller plane in addition to the DetNet specific use of MPLS
encapsulation as specified by this document.
This document specifies the DetNet data plane operation and the on-
wire encapsulation of DetNet flows over an MPLS-based Packet Switched
Network (PSN) using the service reference model. MPLS encapsulation
already provides a solid foundation of building blocks to enable the
DetNet service and forwarding sub-layer functions. MPLS encapsulated
DetNet can be carried over a variety of different network
technologies that can provide the DetNet required level of service.
However, the specific details of how DetNet MPLS is carried over
different network technologies are out of scope of this document.
MPLS encapsulated DetNet flows can carry different types of traffic.
The details of the types of traffic that are carried in DetNet are
also out of scope of this document. An example of IP using DetNet
MPLS sub-networks can be found in [I-D.ietf-detnet-ip]. DetNet MPLS
may use an associated controller and Operations, Administration, and
Maintenance (OAM) functions that are defined outside of this
document.
Background information common to all data planes for DetNet can be
found in the DetNet Data Plane Framework
[I-D.ietf-detnet-data-plane-framework].
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2. Terminology
2.1. Terms Used in This Document
This document uses the terminology established in the DetNet
architecture [RFC8655] and the DetNet Data Plane Framework
[I-D.ietf-detnet-data-plane-framework]. The reader is assumed to be
familiar with these documents, any terminology defined therein and
basic MPLS related terminologies in [RFC3031].
The following terminology is introduced in this document:
F-Label A Detnet "forwarding" label that identifies the LSP
used to forward a DetNet flow across an MPLS PSN, i.e.,
a hop-by-hop label used between label switching routers
(LSR).
S-Label A DetNet "service" label that is used between DetNet
nodes that implement the DetNet service sub-layer
functions. An S-Label is used to identify a DetNet
flow at DetNet service sub-layer at a receiving DetNet
node.
A-Label A special case of an S-Label, whose aggregation
properties are known only at the aggregation and
deaggregation end-points.
d-CW A DetNet Control Word (d-CW) is used for sequencing
information of a DetNet flow at the DetNet service sub-
layer.
2.2. Abbreviations
The following abbreviations are used in this document:
CoS Class of Service.
CW Control Word.
DetNet Deterministic Networking.
LSR Label Switching Router.
MPLS Multiprotocol Label Switching.
MPLS-TE Multiprotocol Label Switching - Traffic Engineering.
MPLS-TP Multiprotocol Label Switching - Transport Profile.
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OAM Operations, Administration, and Maintenance.
PE Provider Edge.
PEF Packet Elimination Function.
PRF Packet Replication Function.
PREOF Packet Replication, Elimination and Ordering Functions.
POF Packet Ordering Function.
PSN Packet Switched Network.
PW PseudoWire.
QoS Quality of Service.
S-PE Switching Provider Edge.
T-PE Terminating Provider Edge.
TSN Time-Sensitive Network.
2.3. 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.
3. DetNet MPLS Data Plane Overview
3.1. Layers of DetNet Data Plane
MPLS provides a wide range of capabilities that can be utilised by
DetNet. A straight forward approach utilizing MPLS for a DetNet
service sub-layer is based on the existing pseudowire (PW)
encapsulations and by utilizing existing MPLS Traffic Engineering
encapsulations and mechanisms. Background on PWs can be found in
[RFC3985] and [RFC3031]. Background on MPLS Traffic Engineering can
be found in [RFC3272] and [RFC3209].
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DetNet MPLS
.
Bottom of Stack .
(inner label) +------------+
| Service | d-CW, S-Label (A-Label)
+------------+
| Forwarding | F-Label(s)
+------------+
Top of Stack .
(outer label) .
Figure 1: DetNet Adaptation to MPLS Data Plane
The DetNet MPLS data plane representation is illustrated in Figure 1.
The service sub-layer includes a DetNet control word (d-CW) and an
identifying service label (S-Label). The DetNet control word (d-CW)
conforms to the Generic PW MPLS Control Word (PWMCW) defined in
[RFC4385]. An aggregation label (A-Label) is a special case of
S-Label used for aggregation.
A node operating on a received DetNet flow at the Detnet service sub-
layer uses the local context associated with a received S-Label,
i.e., a received F-Label, to determine which local DetNet
operation(s) are applied to that packet. An S-Label may be taken
from the platform label space [RFC3031], making it unique, enabling
DetNet flow identification regardless of which input interface or LSP
the packet arrives on. It is important to note that S-Label values
are driven by the receiver, not the sender.
The DetNet forwarding sub-layer is supported by zero or more
forwarding labels (F-Labels). MPLS Traffic Engineering
encapsulations and mechanisms can be utilized to provide a forwarding
sub-layer that is responsible for providing resource allocation and
explicit routes.
3.2. DetNet MPLS Data Plane Scenarios
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DetNet MPLS Relay Transit Relay DetNet MPLS
End System Node Node Node End System
(T-PE) (S-PE) (LSR) (S-PE) (T-PE)
+----------+ +----------+
| Appl. |<------------ End to End Service ----------->| Appl. |
+----------+ +---------+ +---------+ +----------+
| Service |<--| Service |-- DetNet flow --| Service |-->| Service |
+----------+ +---------+ +----------+ +---------+ +----------+
|Forwarding| |Fwd| |Fwd| |Forwarding| |Fwd| |Fwd| |Forwarding|
+-------.--+ +-.-+ +-.-+ +----.---.-+ +-.-+ +-.-+ +---.------+
: Link : / ,-----. \ : Link : / ,-----. \
+........+ +-[ Sub ]-+ +......+ +-[ Sub ]-+
[Network] [Network]
`-----' `-----'
|<- LSP -->| |<-------- LSP -----------| |<--- LSP -->|
|<----------------- DetNet MPLS --------------------->|
Figure 2: A DetNet MPLS Network
Figure 2 illustrates a hypothetical DetNet MPLS-only network composed
of DetNet aware MPLS enabled end systems, operating over a DetNet
aware MPLS network. In this figure, the relay nodes are PE devices
that define the MPLS LSP boundaries and the transit nodes are LSRs.
DetNet end systems and relay nodes understand the particular needs of
DetNet flows and provide both DetNet service and forwarding sub-layer
functions. In the case of MPLS, DetNet service-aware nodes add,
remove and process d-CWs, S-Labels and F-labels as needed. DetNet
MPLS nodes provide functionality analogous to T-PEs when they sit at
the edge of an MPLS domain, and S-PEs when they are in the middle of
an MPLS domain, see [RFC6073].
In a DetNet MPLS network, transit nodes may be DetNet service aware
or may be DetNet unaware MPLS Label Switching Routers (LSRs). In
this latter case, such LSRs would be unaware of the special
requirements of the DetNet service sub-layer, but would still provide
traffic engineering functions and the QoS capabilities needed to
ensure that the (TE) LSPs meet the service requirements of the
carried DetNet flows.
The application of DetNet using MPLS supports a number of control
plane/management plane types. These types support certain MPLS data
plane deployments. For example RSVP-TE, MPLS-TP, or MPLS Segment
Routing (when extended to support resource allocation) are all valid
MPLS deployment cases.
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Figure 3 illustrates how an end-to-end MPLS-based DetNet service is
provided in a more detail. In this figure, the customer end systems,
CE1 and CE2, are able to send and receive MPLS encapsulated DetNet
flows, and R1, R2 and R3 are relay nodes in the middle of a DetNet
network. The 'X' in the end systems, and relay nodes represents
potential DetNet compound flow packet replication and elimination
points. In this example, service protection is supported utilizing
at least two DetNet member flows and TE LSPs. For a unidirectional
flow, R1 supports PRF and R3 supports PEF and POF. Note that the
relay nodes may change the underlying forwarding sub-layer, for
example tunneling MPLS over IEEE 802.1 TSN
[I-D.ietf-detnet-mpls-over-tsn], or simply over interconnect network
links.
DetNet DetNet
DetNet Service Transit Transit Service DetNet
MPLS | |<-Tnl->| |<-Tnl->| | MPLS
End | V 1 V V 2 V | End
System | +--------+ +--------+ +--------+ | System
+---+ | | R1 |=======| R2 |=======| R3 | | +---+
| X...DFa...|._X_....|..DF1..|.__ ___.|..DF3..|...._X_.|.DFa..|.X |
|CE1|========| \ | | X | | / |======|CE2|
| | | | \_.|..DF2..|._/ \__.|..DF4..|._/ | | | |
+---+ | |=======| |=======| | +---+
^ +--------+ +--------+ +--------+ ^
| Relay Node Relay Node Relay Node |
| (S-PE) (S-PE) (S-PE) |
| |
|<---------------------- DetNet MPLS --------------------->|
| |
|<--------------- End to End DetNet Service -------------->|
-------------------------- Data Flow ------------------------->
X = Optional service protection (none, PRF, PREOF, PEF/POF)
DFx = DetNet member flow x over a TE LSP
Figure 3: MPLS-Based Native DetNet
4. MPLS-Based DetNet Data Plane Solution
4.1. DetNet Over MPLS Encapsulation Components
To carry DetNet over MPLS the following is required:
1. A method of identifying the MPLS payload type.
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2. A method of identifying the DetNet flow(s) to the processing
element.
3. A method of distinguishing DetNet OAM packets from DetNet data
packets.
4. A method of carrying the DetNet sequence number.
5. A suitable LSP to deliver the packet to the egress PE.
6. A method of carrying queuing and forwarding indication.
In this design an MPLS service label (the S-Label), is similar to a
pseudowire (PW) label [RFC3985], and is used to identify both the
DetNet flow identity and the payload MPLS payload type satisfying (1)
and (2) in the list above. OAM traffic discrimination happens
through the use of the Associated Channel method described in
[RFC4385]. The DetNet sequence number is carried in the DetNet
Control word which carries the Data/OAM discriminator. To simplify
implementation and to maximize interoperability two sequence number
sizes are supported: a 16 bit sequence number and a 28 bit sequence
number. The 16 bit sequence number is needed to support some types
of legacy clients. The 28 bit sequence number is used in situations
where it is necessary ensure that in high speed networks the sequence
number space does not wrap whilst packets are in flight.
The LSP used to forward the DetNet packet is not restricted regarding
any method used for establishing that LSP (for example, MPLS-LDP,
MPLS-TE, MPLS-TP [RFC5921], MPLS-SR [RFC8660], etc.). The LSP
(F-Label) label(s) and/or the S-Label may be used to indicate the
required queue processing as well as the forwarding parameters. Note
that the possible use of Penultimate Hop Popping (PHP) means that the
S-Label may be the only label received at the terminating DetNet
service.
4.2. MPLS Data Plane Encapsulation
Figure 4 illustrates a DetNet data plane MPLS encapsulation. The
MPLS-based encapsulation of the DetNet flows is well suited for the
scenarios described in [I-D.ietf-detnet-data-plane-framework].
Furthermore, an end-to-end DetNet service i.e., native DetNet
deployment (see Section 3.2) is also possible if DetNet end systems
are capable of initiating and termination MPLS encapsulated packets.
The MPLS-based DetNet data plane encapsulation consists of:
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o DetNet control word (d-CW) containing sequencing information for
packet replication and duplicate elimination purposes, and the OAM
indicator.
o DetNet service Label (S-Label) that identifies a DetNet flow at
the receiving DetNet service sub-layer processing node.
o Zero or more Detnet MPLS Forwarding label(s) (F-Label) used to
direct the packet along the label switched path (LSP) to the next
DetNet service sub-layer processing node along the path. When
Penultimate Hop Popping is in use there may be no label F-Label in
the protocol stack on the final hop.
o The necessary data-link encapsulation is then applied prior to
transmission over the physical media.
DetNet MPLS-based encapsulation
+---------------------------------+
| |
| DetNet App-Flow |
| Payload Packet |
| |
+---------------------------------+ <--\
| DetNet Control Word | |
+---------------------------------+ +--> DetNet data plane
| S-Label | | MPLS encapsulation
+---------------------------------+ |
| [ F-Label(s) ] | |
+---------------------------------+ <--/
| Data-Link |
+---------------------------------+
| Physical |
+---------------------------------+
Figure 4: Encapsulation of a DetNet App-Flow in an MPLS PSN
4.2.1. DetNet Control Word and the DetNet Sequence Number
A DetNet control word (d-CW) conforms to the Generic PW MPLS Control
Word (PWMCW) defined in [RFC4385]. The d-CW formatted as shown in
Figure 5 MUST be present in all DetNet packets containing app-flow
data. This format of the d-CW was created in order (1) to allow
larger sequence number space to avoid sequence number rollover
frequency in some applications and (2) to allow sequence numbering
systems that include the value zero as a valid sequence number, which
simplifies implementation.
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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 0 0 0| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: DetNet Control Word
(bits 0 to 3)
Per [RFC4385], MUST be set to zero (0).
Sequence Number (bits 4 to 31)
An unsigned value implementing the DetNet sequence number. The
sequence number space is a circular one with no restriction on
initial value.
A separate sequence number space MUST be maintained by the node that
adds the d-CW for each DetNet app-flow, i.e., DetNet service. The
following sequence number field lengths MUST be supported:
0 bits
16 bits
28 bits
The sequence number length MUST be provisioned on a per Detnet
service basis via configuration, i.e., via the controller plane
described in [I-D.ietf-detnet-data-plane-framework].
A 0 bit sequence number field length indicates that there is no
DetNet sequence number used for the flow. When the length is zero,
the sequence number field MUST be set to zero (0) on all packets sent
for the flow.
When the sequence number field length is 16 or 28 bits for a flow,
the sequence number MUST be incremented by one for each new app-flow
packet sent. When the field length is 16 bits, d-CW bits 4 to 15
MUST be set to zero (0). The values carried in this field can wrap
and it is important to note that zero (0) is a valid field value.
For example, where the sequence number size is 16 bits, the sequence
will contain: 65535, 0, 1, where zero (0) is an ordinary sequence
number.
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It is important to note that this document differs from [RFC4448]
where a sequence number of zero (0) is used to indicate that the
sequence number check algorithm is not used.
The sequence number is optionally used during receive processing as
described below in Section 4.2.2.2 and Section 4.2.2.3.
4.2.2. S-Labels
A DetNet flow at the DetNet service sub-layer is identified by an
S-Label. MPLS-aware DetNet end systems and edge nodes, which are by
definition MPLS ingress and egress nodes, MUST add (push) and remove
(pop) a DetNet service-specific d-CW and S-Label. Relay nodes MAY
swap S-Label values when processing a DetNet flow, i.e., incoming and
outgoing S-Labels of a DetNet flow can be different.
S-Label values MUST be provisioned per DetNet service via
configuration, i.e., via the controller plane described in
[I-D.ietf-detnet-data-plane-framework]. Note that S-Labels provide
identification at the downstream DetNet service sub-layer receiver,
not the sender. As such, S-Labels MUST be allocated by the entity
that controls the service sub-layer receiving node's label space, and
MAY be allocated from the platform label space [RFC3031]. Because
S-Labels are local to each node rather than being a global identifier
within a domain, they must be advertised to their upstream DetNet
service-aware peer nodes (i.e., a DetNet MPLS End System or a DetNet
Relay or Edge Node) and interpreted in the context of their received
F-Label(s). In some PREOF topologies, the node performing
replication will be sending to multiple nodes performing PEF or POF,
and may need to send different S-Label values for the different
member flows for the same DetNet service.
An S-Label will normally be at the bottom of the label stack once the
last F-Label is removed, immediately preceding the d-CW. To support
service sub-layer level OAM, an OAM Associated Channel Header (ACH)
[RFC4385] together with a Generic Associated Channel Label (GAL)
[RFC5586] MAY be used in place of a d-CW.
Similarly, an Entropy Label Indicator/Entropy Label (ELI/EL)
[RFC6790] MAY be carried below the S-Label in the label stack in
networks where DetNet flows would otherwise receive ECMP treatment.
When ELs are used, the same EL value SHOULD be used for all of the
packets sent using a specific S-Label to force the flow to follow the
same path. However, as outlined in
[I-D.ietf-detnet-data-plane-framework] the use of ECMP for DetNet
flows is NOT RECOMMENDED. ECMP MAY be used for non-DetNet flows
within a DetNet domain.
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When receiving a DetNet MPLS packet, an implementation MUST identify
the DetNet service associated with the incoming packet based on the
S-Label. When a node is using platform labels for S-Labels, no
additional information is needed as the S-label uniquely identifies
the DetNet service. In the case where platform labels are not used,
zero or more F-Labels proceeding the S-Label MUST be used together
with the S-Label to uniquely identify the DetNet service associated
with a received packet. The incoming interface MAY also be used
together with any present F-Label(s) and the S-Label to uniquely
identify an incoming DetNet service, for example, in the case where
PHP is used. Note that choice to use platform label space for
S-Label or S-Label plus one or more F-Labels to identify DetNet
services is a local implementation choice, with one caveat. When one
or more F-labels, or incoming interface, is needed together with an
S-Label to uniquely identify a service, the controller plane must
ensure that incoming DetNet MPLS packets arrive with the needed
information (F-label(s) and/or incoming interface) and provision the
needed information. The provisioned information MUST then be used to
identify incoming DetNet service based on the combination of S-Label
and F-Label(s) or incoming interface.
The use of platform labels for S-Labels matches other pseudowire
encapsulations for consistency but there is no hard requirement in
this regard.
Implementation details of PREOF functions are out of scope for this
document. [IEEE802.1CB-2017] defines equivalent replication and
elimination specific aspects, which can be applied to PRF and PEF.
4.2.2.1. Packet Replication Function Processing
The Packet Replication Function (PRF) function MAY be supported by an
implementation for outgoing DetNet flows. The use of the PRF for a
particular DetNet service MUST be provisioned via configuration,
i.e., via the controller plane described in
[I-D.ietf-detnet-data-plane-framework]. When replication is
configured, the same app-flow data will be sent over multiple
outgoing DetNet member flows using forwarding sub-layer LSPs. An
S-Label value MUST be configured per outgoing member flow. The same
d-CW field value MUST be used on all outgoing member flows for each
replicated MPLS packet.
4.2.2.2. Packet Elimination Function Processing
Implementations MAY support the Packet Elimination Function (PEF) for
received DetNet MPLS flows. When supported, use of the PEF for a
particular DetNet service MUST be provisioned via configuration,
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i.e., via the controller plane described in
[I-D.ietf-detnet-data-plane-framework].
After a DetNet service is identified for a received DetNet MPLS
packet, as described above, if PEF is configured for that DetNet
service, duplicate (replicated) instances of a particular sequence
number MUST be discarded. The specific mechanisms used for an
implementation to identify which received packets are duplicates and
which are new is an implementation choice. Note that per
Section 4.2.1 the sequence number field length may be 16 or 28 bits,
and the field value can wrap. PEF MUST NOT be used with DetNet flows
configured with a d-CW sequence number field length of 0 bits.
An implementation MAY constrain the maximum number of sequence
numbers that are tracked on either a platform-wide or per flow basis.
Some implementations MAY support the provisioning of the maximum
number of sequence numbers that are tracked on either a platform-wide
or per flow basis.
4.2.2.3. Packet Ordering Function Processing
A function that is related to in-order delivery is the Packet
Ordering Function (POF). Implementations MAY support POF. When
supported, use of the POF for a particular DetNet service MUST be
provisioned via configuration, i.e., via the controller plane
described by [I-D.ietf-detnet-data-plane-framework]. Implementations
MAY require that PEF and POF be used in combination. There is no
requirement related to the order of execution of the Packet
Elimination and Ordering Functions in an implementation.
After a DetNet service is identified for a received DetNet MPLS
packet, as described above, if POF is configured for that DetNet
service, packets MUST be processed in the order indicated in the
received d-CW sequence number field, which may not be in the order
the packets are received. As defined in Section 4.2.1 the sequence
number field length may be 16 or 28 bits, is incremented by one (1)
for each new MPLS packet sent for a particular DetNet service, and
the field value can wrap. The specific mechanisms used for an
implementation to identify the order of received packets is an
implementation choice.
An implementation MAY constrain the maximum number of out of order
packets that can be processed, on either a platform-wide or per flow
basis. The number of out of order packets that can be processed also
impacts the latency of a flow.
The latency impact on the system resources needed to support a
specific DetNet flow will need to be evaluated by the controller
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plane based on that flow's traffic specification. An example traffic
specification that can be used with MPLS with Traffic Engineering
(MPLS-TE) can be found in [RFC2212].
DetNet implementations can use flow-specific requirements (e.g.,
maximum number of out-of-order packets, maximum latency of the flow)
for configuration of POF-related buffers. POF implementation details
are out-of-scope for this document and POF configuration parameters
are implementation specific. The Controller Plane identifies and
sets the POF configuration parameters.
4.2.3. F-Labels
F-Labels support the DetNet forwarding sub-layer. F-Labels are used
to provide LSP-based connectivity between DetNet service sub-layer
processing nodes.
4.2.3.1. Service Sub-Layer Related Processing
DetNet MPLS end systems, edge nodes and relay nodes may operate at
the DetNet service sub-layer with understanding of DetNet services
and their requirements. As mentioned earlier, when operating at this
layer such nodes can push, pop or swap (pop then push) S-Labels. In
all cases, the F-Label(s) used for a DetNet service are always
replaced and the following procedures apply.
When sending a DetNet flow, zero or more F-Labels MAY be pushed on
top of an S-Label by the node pushing an S-Label. The F-Label(s) to
be pushed when sending a particular DetNet service MUST be
provisioned per outgoing S-Label via configuration, i.e., via the
controller plane discussed in [I-D.ietf-detnet-data-plane-framework].
F-Label(s) can also provide context for an S-Label. To allow for the
omission of F-Label(s), an implementation SHOULD also allow an
outgoing interface to be configured per S-Label.
Note, when PRF is supported, the same app-flow data will be sent over
multiple outgoing DetNet member flows using forwarding sub-layer
LSPs. This means that implementation may be sending different sets
of F-Labels per DetNet member flow, each with a different S-Label.
When a single set of F-Labels is provisioned for a particular
outgoing S-Label, that set of F-labels MUST be pushed after the
S-Label is pushed. The outgoing packet is then forwarded as
described below in Section 4.2.3.2. When a single outgoing interface
is provisioned, the outgoing packet is then forwarded as described
below in Section 4.2.3.2.
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When multiple sets of outgoing F-Labels or interfaces are provisioned
for a particular DetNet service (i.e., for PRF), a copy of the
outgoing packet, including the pushed member flow-specific S-Label,
MUST be made per F-label set and outgoing interface. Each set of
provisioned F-Labels are then pushed onto a copy of the packet. Each
copy is then forwarded as described below in Section 4.2.3.2.
As described in the previous section, when receiving a DetNet MPLS
flow, an implementation identifies the DetNet service associated with
the incoming packet based on the S-Label. When a node is using
platform labels for S-Labels, any F-Labels can be popped and the
S-label uniquely identifies the DetNet service. In the case where
platform labels are not used, incoming F-Label(s) and, optionally,
the incoming interface MUST also be provisioned for a DetNet service.
4.2.3.2. Common F-Label Processing
All DetNet aware MPLS nodes process F-Labels as needed to meet the
service requirements of the DetNet flow or flows carried in the LSPs
represented by the F-Labels. This includes normal push, pop and swap
operations. Such processing is essentially the same type of
processing provided for TE LSPs, although the specific service
parameters, or traffic specification, can differ. When the DetNet
service parameters of the DetNet flow or flows carried in an LSP
represented by an F-Label can be met by an existing TE mechanism, the
forwarding sub-layer processing node MAY be a DetNet unaware, i.e.,
standard, MPLS LSR. Such TE LSPs may provide LSP forwarding service
as defined in, but not limited to, [RFC3209], [RFC3270], [RFC3272],
[RFC3473], [RFC4875], [RFC5440], and [RFC8306].
More specifically, as mentioned above, the DetNet forwarding sub-
layer provides explicit routes and allocated resources, and F-Labels
are used to map to each. Explicit routes are supported based on the
topmost (outermost) F-Label that is pushed or swapped and the LSP
that corresponds to this label. This topmost (outgoing) label MUST
be associated with a provisioned outgoing interface and, for non-
point-to-point outgoing interfaces, a next hop LSR. Note that this
information MUST be provisioned via configuration or the controller
plane. In the previously mentioned special case where there are no
added F-labels and the outgoing interface is not a point-to-point
interface, the outgoing interface MUST also be associated with a next
hop LSR.
Resources may be allocated in a hierarchical fashion per LSP that is
represented by each F-Label. Each LSP MAY be provisioned with a
service parameter that dictates the specific traffic treatment to be
received by the traffic carried over that LSP. Implementations of
this document MUST ensure that traffic carried over each LSP
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represented by one or more F-Labels receives the traffic treatment
provisioned for that LSP. Typical mechanisms used to provide
different treatment to different flows includes the allocation of
system resources (such as queues and buffers) and provisioning of
related parameters (such as shaping, and policing) that may be found
in implementations of Resource ReSerVation Protocol (RSVP) [RFC2205]
(RSVP) and RSVP-TE [RFC3209] and [RFC3473]. Support can also be
provided via an underlying network technology such IEEE802.1 TSN
[I-D.ietf-detnet-mpls-over-tsn]. The specific mechanisms selected by
a DetNet node to ensure DetNet service delivery requirements are met
for supported DetNet flows is outside the scope of this document.
Packets that are marked in a way that do not correspond to allocated
resources, e.g., lack a provisioned F-Label, can disrupt the QoS
offered to properly reserved DetNet flows by using resources
allocated to the reserved flows. Therefore, the network nodes of a
DetNet network:
o MUST defend the DetNet QoS by discarding or remarking (to an
allocated DetNet flow or non-competing non-DetNet flow) packets
received that are not associated with a completed resource
allocation.
o MUST NOT use a DetNet allocated resource, e.g. a queue or shaper
reserved for DetNet flows, for any packet that does match the
corresponding DetNet flow.
o MUST ensure a QoS flow does not exceed its allocated resources or
provisioned service level,
o MUST ensure a CoS flow or service class does not impact the
service delivered to other flows. This requirement is similar to
the requirement for MPLS LSRs that CoS LSPs do not impact the
resources allocated to TE LSPs, e.g., via [RFC3473].
Subsequent sections provide additional considerations related to CoS
(Section 4.6.1), QoS (Section 4.6.2) and aggregation (Section 4.4).
4.3. OAM Indication
OAM follows the procedures set out in [RFC5085] with the restriction
that only Virtual Circuit Connectivity Verification (VCCV) type 1 is
supported.
As shown in Figure 3 of [RFC5085] when the first nibble of the d-CW
is 0x0 the payload following the d-CW is normal user data. However,
when the first nibble of the d-CW is 0x1, the payload that follows
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the d-CW is an OAM payload with the OAM type indicated by the value
in the d-CW Channel Type field.
The reader is referred to [RFC5085] for a more detailed description
of the Associated Channel mechanism, and to the DetNet work on OAM
for more information DetNet OAM.
Additional considerations on DetNet-specific OAM are subjects for
further study.
4.4. Flow Aggregation
The ability to aggregate individual flows, and their associated
resource control, into a larger aggregate is an important technique
for improving scaling of control in the data, management and control
planes. The DetNet data plane allows for the aggregation of DetNet
flows, to improved scaling. There are two methods of supporting flow
aggregation covered in this section.
The resource control and management aspects of aggregation (including
the configuration of queuing, shaping, and policing) are the
responsibility of the DetNet controller plane and is out of scope of
this documents. It is also the responsibility of the controller
plane to ensure that consistent aggregation methods are used.
4.4.1. Aggregation Via LSP Hierarchy
DetNet flows forwarded via MPLS can leverage MPLS-TE's existing
support for hierarchical LSPs (H-LSPs), see [RFC4206]. H-LSPs are
typically used to aggregate control and resources, they may also be
used to provide OAM or protection for the aggregated LSPs. Arbitrary
levels of aggregation naturally falls out of the definition for
hierarchy and the MPLS label stack [RFC3032]. DetNet nodes which
support aggregation (LSP hierarchy) map one or more LSPs (labels)
into and from an H-LSP. Both carried LSPs and H-LSPs may or may not
use the TC field, i.e., L-LSPs or E-LSPs [RFC3270]. Such nodes will
need to ensure that individual LSPs and H-LSPs receive the traffic
treatment required to ensure the required DetNet service is
preserved.
Additional details of the traffic control capabilities needed at a
DetNet-aware node may be covered in the new service definitions
mentioned above or in separate future documents. Controller plane
mechanisms will also need to ensure that the service required on the
aggregate flow are provided, which may include the discarding or
remarking mentioned in the previous sections.
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4.4.2. Aggregating DetNet Flows as a new DetNet flow
An aggregate can be built by layering DetNet flows, including both
their S-Label and, when present, F-Labels as shown below:
+---------------------------------+
| |
| DetNet Flow |
| Payload Packet |
| |
+---------------------------------+ <--\
| DetNet Control Word | |
+=================================+ |
| S-Label | |
+---------------------------------+ |
| [ F-Label(s) ] | +----DetNet data plane
+---------------------------------+ |
| DetNet Control Word | |
+=================================+ |
| A-Label | |
+---------------------------------+ |
| F-Label(s) | <--/
+---------------------------------+
| Data-Link |
+---------------------------------+
| Physical |
+---------------------------------+
Figure 6: DetNet Aggregation as a new DetNet Flow
Both the aggregation label, which is referred to as an A-Label, and
the individual flow's S-Label have their MPLS S bit set indicating
bottom of stack, and the d-CW allows the PREOF to work. An A-Label
is a special case of an S-Label, whose properties are known only at
the aggregation and deaggregation end-points.
It is a property of the A-Label that what follows is a d-CW followed
by an MPLS label stack. A relay node processing the A-Label would
not know the underlying payload type, and the A-Label would be
processed as a normal S-Label. This would only be known to a node
that was a peer of the node imposing the S-Label. However there is
no real need for it to know the payload type during aggregation
processing.
As in the previous section, nodes supporting this type of aggregation
will need to ensure that individual and aggregated flows receive the
traffic treatment required to ensure the required DetNet service is
preserved. Also, it is the controller plane's responsibility to
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ensure that the service required on the aggregate flow are properly
provisioned.
4.5. Service Sub-Layer Considerations
The edge and relay node internal procedures related to PREOF are
implementation specific. The order of a packet elimination or
replication is out of scope in this specification.
It is important that the DetNet layer is configured such that a
DetNet node never receives its own replicated packets. If it were to
receive such packets the replication function would make the loop
more destructive of bandwidth than a conventional unicast loop.
Ultimately the TTL in the S-Label will cause the packet to die during
a transient loop, but given the sensitivity of applications to packet
latency the impact on the DetNet application would be severe. To
avoid the problem of a transient forwarding loop, changes to an LSP
supporting DetNet MUST be loop-free.
4.5.1. Edge Node Processing
A DetNet Edge node operates in the DetNet forwarding sub-layer and
service sub-layer. An edge node is responsible for matching incoming
packets to the service they require and encapsulating them
accordingly. An edge node may perform PRF, PEF, and or POF. Details
on encapsulation can be found in Section 4.2; details on PRF can be
found in Section 4.2.2.1; details on PEF can be found in
Section 4.2.2.2; and details on POF can be found in Section 4.2.2.3.
4.5.2. Relay Node Processing
A DetNet Relay node operates in the DetNet forwarding sub-layer and
service sub-layer. For DetNet using MPLS forwarding related
processing is performed on the F-Label. This processing is done
within an extended forwarder function. Whether an incoming DetNet
flow receives DetNet specific processing depends on how the
forwarding is programmed. Some relay nodes may be DetNet service
aware for certain DetNet services, while for other DetNet services
these nodes may perform as unmodified LSRs that only understand how
to switch MPLS-TE LSPs, i.e., as a transit node, see Section 4.4.
Again, this is entirely up to how the forwarding has been programmed.
During the elimination and replication process the sequence number of
an incoming DetNet packet MUST be preserved and carried in the
corresponding outgoing DetNet packet. For example, a relay node that
performs both PEF and PRF first performs PEF on incoming packets to
create a compound flow. It then performs PRF and copies the app-flow
data and the d-CW into packets for each outgoing DetNet member flow.
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The internal design of a relay node is out of scope of this document.
However the reader's attention is drawn to the need to make any PREOF
state available to the packet processor(s) dealing with packets to
which the PREOF functions must be applied, and to maintain that state
is such a way that it is available to the packet processor operation
on the next packet in the DetNet flow (which may be a duplicate, a
late packet, or the next packet in sequence).
4.6. Forwarding Sub-Layer Considerations
4.6.1. Class of Service
Class and quality of service, i.e., CoS and QoS, are terms that are
often used interchangeably and confused with each other. In the
context of DetNet, CoS is used to refer to mechanisms that provide
traffic forwarding treatment based on aggregate group basis and QoS
is used to refer to mechanisms that provide traffic forwarding
treatment based on a specific DetNet flow basis. Examples of
existing network level CoS mechanisms include DiffServ which is
enabled by IP header differentiated services code point (DSCP) field
[RFC2474] and MPLS label traffic class field [RFC5462], and at Layer-
2, by IEEE 802.1p priority code point (PCP).
CoS for DetNet flows carried in PWs and MPLS is provided using the
existing MPLS Differentiated Services (DiffServ) architecture
[RFC3270]. Both E-LSP and L-LSP MPLS DiffServ modes MAY be used to
support DetNet flows. The Traffic Class field (formerly the EXP
field) of an MPLS label follows the definition of [RFC5462] and
[RFC3270]. The Uniform, Pipe, and Short Pipe DiffServ tunneling and
TTL processing models are described in [RFC3270] and [RFC3443] and
MAY be used for MPLS LSPs supporting DetNet flows. MPLS Explicit
Congestion Notification (ECN) MAY also be used as defined in ECN
[RFC5129] and updated by [RFC5462].
4.6.2. Quality of Service
In addition to explicit routes, and packet replication and
elimination, described in Section 4 above, DetNet provides zero
congestion loss and bounded latency and jitter. As described in
[RFC8655], there are different mechanisms that may be used separately
or in combination to deliver a zero congestion loss service. This
includes Quality of Service (QoS) mechanisms at the MPLS layer, that
may be combined with the mechanisms defined by the underlying network
layer such as 802.1TSN.
Quality of Service (QoS) mechanisms for flow specific traffic
treatment typically includes a guarantee/agreement for the service,
and allocation of resources to support the service. Example QoS
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mechanisms include discrete resource allocation, admission control,
flow identification and isolation, and sometimes path control,
traffic protection, shaping, policing and remarking. Example
protocols that support QoS control include Resource ReSerVation
Protocol (RSVP) [RFC2205] (RSVP) and RSVP-TE [RFC3209] and [RFC3473].
The existing MPLS mechanisms defined to support CoS [RFC3270] can
also be used to reserve resources for specific traffic classes.
A baseline set of QoS capabilities for DetNet flows carried in PWs
and MPLS can be provided by MPLS with Traffic Engineering (MPLS-TE)
[RFC3209] and [RFC3473]. TE LSPs can also support explicit routes
(path pinning). Current service definitions for packet TE LSPs can
be found in "Specification of the Controlled Load Quality of
Service", [RFC2211], "Specification of Guaranteed Quality of
Service", [RFC2212], and "Ethernet Traffic Parameters", [RFC6003].
Additional service definitions are expected in future documents to
support the full range of DetNet services. In all cases, the
existing label-based marking mechanisms defined for TE-LSPs and even
E-LSPs are use to support the identification of flows requiring
DetNet QoS.
5. Management and Control Information Summary
The specific information needed for the processing of each DetNet
service depends on the DetNet node type and the functions being
provided on the node. This section summarizes based on the DetNet
sub-layer and if the DetNet traffic is being sent or received. All
DetNet node types are DetNet forwarding sub-layer aware, while all
but transit nodes are service sub-layer aware. This is shown in
Figure 2.
Much like other MPLS labels, there are a number of alternatives
available for DetNet S-Label and F-Label advertisement to an upstream
peer node. These include distributed signaling protocols such as
RSVP-TE, centralized label distribution via a controller that manages
both the sender and the receiver using NETCONF/YANG, BGP, PCEP, etc.,
and hybrid combinations of the two. The details of the controller
plane solution required for the label distribution and the management
of the label number space are out of scope of this document. There
are particular DetNet considerations and requirements that are
discussed in [I-D.ietf-detnet-data-plane-framework]. Conformance
language is not used in the summary since it applies to future
mechanisms such as those that may be provided in signaling and YANG
models, e.g., [I-D.ietf-detnet-yang].
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5.1. Service Sub-Layer Information Summary
The following summarizes the information that is needed on service
sub-layer aware nodes that transmit DetNet MPLS traffic, on a per
service basis:
o App-Flow identification information, e.g., IP information as
defined in [I-D.ietf-detnet-ip-over-mpls]. Note, this information
is not needed on DetNet relay nodes.
o The sequence number length to be used for the service. Valid
values include 0, 16 and 28 bits. 0 bits cannot be used when PEF
or POF is configured for the service.
o If PRF is to be provided for the service.
o The outgoing S-Label for each of the service's outgoing DetNet
(member) flows.
o The forwarding sub-layer information associated with the output of
the service sub-layer. Note that when the PRF function is
provisioned, this information is per DetNet member flow.
Logically the forwarding sub-layer information is a pointer to
further details of transmission of Detnet flows at the forwarding
sub-layer.
The following summarizes the information that is needed on service
sub-layer aware nodes that receive DetNet MPLS traffic, on a per
service basis:
o The forwarding sub-layer information associated with the input of
the service sub-layer. Note that when the PEF function is
provisioned, this information is per DetNet member flow.
Logically the forwarding sub-layer information is a pointer to
further details of the reception of Detnet flows at the forwarding
sub-layer or A-Label.
o The incoming S-Label for the service.
o If PEF or POF is to be provided for the service.
o The sequence number length to be used for the service. Valid
values included 0, 16 and 28 bits. 0 bits cannot be used when PEF
or POF are configured for the service.
o App-Flow identification information, e.g., IP information as
defined in [I-D.ietf-detnet-ip-over-mpls]. Note, this information
is not needed on DetNet relay nodes.
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5.1.1. Service Aggregation Information Summary
Nodes performing aggregation using A-Labels, per
Section Section 4.4.2, require the additional information summarized
in this section.
The following summarizes the additional information that is needed on
a node that sends aggregated flows using A-Labels:
o The S-Labels or F-Labels that are to be carried over each
aggregated service.
o The A-Label associated with each aggregated service.
o The other S-Label information summarized above.
On the receiving node, the A-Label provides the forwarding context of
an incoming interface or an F-Label and is used in subsequent service
or forwarding sub-layer receive processing, as appropriated. The
related additional configuration that may be provided is discussed
elsewhere in this section.
5.2. Forwarding Sub-Layer Information Summary
The following summarizes the information that is needed on forwarding
sub-layer aware nodes that send DetNet MPLS traffic, on a per
forwarding sub-layer flow basis:
o The outgoing F-Label stack to be pushed. The stack may include
H-LSP labels.
o The traffic parameters associated with a specific label in the
stack. Note that there may be multiple sets of traffic parameters
associated with specific labels in the stack, e.g., when H-LSPs
are used.
o Outgoing interface and, for unicast traffic, the next hop
information.
o Sub-network specific parameters on a technology specific basis.
For example, see [I-D.ietf-detnet-mpls-over-tsn].
The following summarizes the information that is needed on forwarding
sub-layer aware nodes that receive DetNet MPLS traffic, on a per
forwarding sub-layer flow basis:
o The incoming interface. For some implementations and deployment
scenarios, this information may not be needed.
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o The incoming F-Label stack to be popped. The stack may include
H-LSP labels.
o How the incoming forwarding sub-layer flow is to be handled, i.e.,
forwarded as a transit node, or provided to the service sub-layer.
It is the responsibility of the DetNet controller plane to properly
provision both flow identification information and the flow-specific
resources needed to provided the traffic treatment needed to meet
each flow's service requirements. This applies for aggregated and
individual flows.
6. Security Considerations
Detailed security considerations for DetNet are cataloged in
[I-D.ietf-detnet-security], and more general security considerations
are described in [RFC8655]. This section considers exclusively
security considerations which are specific to the DetNet MPLS data
plane. The considerations raised related to MPLS networks in general
in [RFC5920] are equally applicable to the the DetNet MPLS data
plane.
Security aspects which are unique to DetNet are those whose aim is to
protect the support of specific quality of service aspects of DetNet,
which are primarily to deliver data flows with extremely low packet
loss rates and bounded end-to-end delivery latency. Achieving such
loss rates and bounded latency may not be possible in the face of a
highly capable adversary, such as the one envisioned by the Internet
Threat Model of BCP 72 that can arbitrarily drop or delay any or all
traffic. In order to present meaningful security considerations, we
consider a somewhat weaker attacker who does not control the physical
links of the DetNet domain, but may have the ability to control a
network node within the boundary of the DetNet domain.
An additional consideration for the DetNet data plane is to maintain
integrity of data and delivery of the associated DetNet service
traversing the DetNet network. Application flows can be protected
through whatever means are provided by the underlying technology.
For example, encryption may be used, such as that provided by IPsec
[RFC4301] for IP flows and/or by an underlying sub-net using MACSec
[IEEE802.1AE-2018] for IP over Ethernet (Layer-2) flows. MPLS
doesn't provide any native security services to account for
confidentiality and integrity.
From a data plane perspective this document does not add or modify
any application header information.
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At the management and control level DetNet flows are identified on a
per-flow basis, which may provide controller plane attackers with
additional information about the data flows (when compared to
controller planes that do not include per-flow identification). This
is an inherent property of DetNet which has security implications
that should be considered when determining if DetNet is a suitable
technology for any given use case.
To provide uninterrupted availability of the DetNet service,
provisions can be made against DOS attacks and delay attacks. To
protect against DOS attacks, excess traffic due to malicious or
malfunctioning devices is prevented or mitigated through the use of
existing mechanisms, for example by policing and shaping incoming
traffic. To prevent DetNet packets having their delay manipulated by
an external entity, precautions need to be taken to ensure that all
devices on an LSP are those intended to be there by the network
operator and that they are well behaved. In addition to physical
security, technical methods such as authentication and authorization
of network equipment and the instrumentation and monitoring of the
LSP packet delay may be used. If a delay attack is suspected,
traffic may be moved to an alternate path, for example through
changing the LSP or management of the PREOF configuration.
7. IANA Considerations
This document makes no IANA requests.
8. Acknowledgements
The authors wish to thank Pat Thaler, Norman Finn, Loa Anderson,
David Black, Rodney Cummings, Ethan Grossman, Tal Mizrahi, David
Mozes, Craig Gunther, George Swallow, Yuanlong Jiang, Jeong-dong Ryoo
and Carlos J. Bernardos for their various contributions to this
work.
9. Contributors
RFC7322 limits the number of authors listed on the front page of a
draft to a maximum of 5. The editor wishes to thank and acknowledge
the following author for contributing text to this draft.
Don Fedyk
LabN Consulting, L.L.C.
Email: dfedyk@labn.net
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10. References
10.1. Normative References
[I-D.ietf-detnet-data-plane-framework]
Varga, B., Farkas, J., Berger, L., Malis, A., and S.
Bryant, "DetNet Data Plane Framework", draft-ietf-detnet-
data-plane-framework-06 (work in progress), May 2020.
[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>.
[RFC2211] Wroclawski, J., "Specification of the Controlled-Load
Network Element Service", RFC 2211, DOI 10.17487/RFC2211,
September 1997, <https://www.rfc-editor.org/info/rfc2211>.
[RFC2212] Shenker, S., Partridge, C., and R. Guerin, "Specification
of Guaranteed Quality of Service", RFC 2212,
DOI 10.17487/RFC2212, September 1997,
<https://www.rfc-editor.org/info/rfc2212>.
[RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
Label Switching Architecture", RFC 3031,
DOI 10.17487/RFC3031, January 2001,
<https://www.rfc-editor.org/info/rfc3031>.
[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>.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>.
[RFC3270] Le Faucheur, F., Wu, L., Davie, B., Davari, S., Vaananen,
P., Krishnan, R., Cheval, P., and J. Heinanen, "Multi-
Protocol Label Switching (MPLS) Support of Differentiated
Services", RFC 3270, DOI 10.17487/RFC3270, May 2002,
<https://www.rfc-editor.org/info/rfc3270>.
[RFC3443] Agarwal, P. and B. Akyol, "Time To Live (TTL) Processing
in Multi-Protocol Label Switching (MPLS) Networks",
RFC 3443, DOI 10.17487/RFC3443, January 2003,
<https://www.rfc-editor.org/info/rfc3443>.
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[RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) Extensions", RFC 3473,
DOI 10.17487/RFC3473, January 2003,
<https://www.rfc-editor.org/info/rfc3473>.
[RFC4206] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP)
Hierarchy with Generalized Multi-Protocol Label Switching
(GMPLS) Traffic Engineering (TE)", RFC 4206,
DOI 10.17487/RFC4206, October 2005,
<https://www.rfc-editor.org/info/rfc4206>.
[RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson,
"Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for
Use over an MPLS PSN", RFC 4385, DOI 10.17487/RFC4385,
February 2006, <https://www.rfc-editor.org/info/rfc4385>.
[RFC5085] Nadeau, T., Ed. and C. Pignataro, Ed., "Pseudowire Virtual
Circuit Connectivity Verification (VCCV): A Control
Channel for Pseudowires", RFC 5085, DOI 10.17487/RFC5085,
December 2007, <https://www.rfc-editor.org/info/rfc5085>.
[RFC5129] Davie, B., Briscoe, B., and J. Tay, "Explicit Congestion
Marking in MPLS", RFC 5129, DOI 10.17487/RFC5129, January
2008, <https://www.rfc-editor.org/info/rfc5129>.
[RFC5462] Andersson, L. and R. Asati, "Multiprotocol Label Switching
(MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic
Class" Field", RFC 5462, DOI 10.17487/RFC5462, February
2009, <https://www.rfc-editor.org/info/rfc5462>.
[RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed.,
"MPLS Generic Associated Channel", RFC 5586,
DOI 10.17487/RFC5586, June 2009,
<https://www.rfc-editor.org/info/rfc5586>.
[RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and
L. Yong, "The Use of Entropy Labels in MPLS Forwarding",
RFC 6790, DOI 10.17487/RFC6790, November 2012,
<https://www.rfc-editor.org/info/rfc6790>.
[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>.
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[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>.
10.2. Informative References
[I-D.ietf-detnet-ip]
Varga, B., Farkas, J., Berger, L., Fedyk, D., and S.
Bryant, "DetNet Data Plane: IP", draft-ietf-detnet-ip-07
(work in progress), July 2020.
[I-D.ietf-detnet-ip-over-mpls]
Varga, B., Berger, L., Fedyk, D., Bryant, S., and J.
Korhonen, "DetNet Data Plane: IP over MPLS", draft-ietf-
detnet-ip-over-mpls-08 (work in progress), September 2020.
[I-D.ietf-detnet-mpls-over-tsn]
Varga, B., Farkas, J., Malis, A., and S. Bryant, "DetNet
Data Plane: MPLS over IEEE 802.1 Time Sensitive Networking
(TSN)", draft-ietf-detnet-mpls-over-tsn-03 (work in
progress), June 2020.
[I-D.ietf-detnet-security]
Grossman, E., Mizrahi, T., and A. Hacker, "Deterministic
Networking (DetNet) Security Considerations", draft-ietf-
detnet-security-12 (work in progress), October 2020.
[I-D.ietf-detnet-yang]
Geng, X., Chen, M., Ryoo, Y., Fedyk, D., Li, Z., and R.
Rahman, "Deterministic Networking (DetNet) Configuration
YANG Model", draft-ietf-detnet-yang-07 (work in progress),
July 2020.
[IEEE802.1AE-2018]
IEEE Standards Association, "IEEE Std 802.1AE-2018 MAC
Security (MACsec)", 2018,
<https://ieeexplore.ieee.org/document/8585421>.
[IEEE802.1CB-2017]
IEEE Standards Association, "IEEE Std 802.1CB-2017 Frame
Replication and Elimination for Reliability", 2017,
<https://ieeexplore.ieee.org/document/8091139>.
[RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S.
Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
Functional Specification", RFC 2205, DOI 10.17487/RFC2205,
September 1997, <https://www.rfc-editor.org/info/rfc2205>.
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[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474,
DOI 10.17487/RFC2474, December 1998,
<https://www.rfc-editor.org/info/rfc2474>.
[RFC3272] Awduche, D., Chiu, A., Elwalid, A., Widjaja, I., and X.
Xiao, "Overview and Principles of Internet Traffic
Engineering", RFC 3272, DOI 10.17487/RFC3272, May 2002,
<https://www.rfc-editor.org/info/rfc3272>.
[RFC3985] Bryant, S., Ed. and P. Pate, Ed., "Pseudo Wire Emulation
Edge-to-Edge (PWE3) Architecture", RFC 3985,
DOI 10.17487/RFC3985, March 2005,
<https://www.rfc-editor.org/info/rfc3985>.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
December 2005, <https://www.rfc-editor.org/info/rfc4301>.
[RFC4448] Martini, L., Ed., Rosen, E., El-Aawar, N., and G. Heron,
"Encapsulation Methods for Transport of Ethernet over MPLS
Networks", RFC 4448, DOI 10.17487/RFC4448, April 2006,
<https://www.rfc-editor.org/info/rfc4448>.
[RFC4875] Aggarwal, R., Ed., Papadimitriou, D., Ed., and S.
Yasukawa, Ed., "Extensions to Resource Reservation
Protocol - Traffic Engineering (RSVP-TE) for Point-to-
Multipoint TE Label Switched Paths (LSPs)", RFC 4875,
DOI 10.17487/RFC4875, May 2007,
<https://www.rfc-editor.org/info/rfc4875>.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol (PCEP)", RFC 5440,
DOI 10.17487/RFC5440, March 2009,
<https://www.rfc-editor.org/info/rfc5440>.
[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010,
<https://www.rfc-editor.org/info/rfc5920>.
[RFC5921] Bocci, M., Ed., Bryant, S., Ed., Frost, D., Ed., Levrau,
L., and L. Berger, "A Framework for MPLS in Transport
Networks", RFC 5921, DOI 10.17487/RFC5921, July 2010,
<https://www.rfc-editor.org/info/rfc5921>.
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[RFC6003] Papadimitriou, D., "Ethernet Traffic Parameters",
RFC 6003, DOI 10.17487/RFC6003, October 2010,
<https://www.rfc-editor.org/info/rfc6003>.
[RFC6073] Martini, L., Metz, C., Nadeau, T., Bocci, M., and M.
Aissaoui, "Segmented Pseudowire", RFC 6073,
DOI 10.17487/RFC6073, January 2011,
<https://www.rfc-editor.org/info/rfc6073>.
[RFC8306] Zhao, Q., Dhody, D., Ed., Palleti, R., and D. King,
"Extensions to the Path Computation Element Communication
Protocol (PCEP) for Point-to-Multipoint Traffic
Engineering Label Switched Paths", RFC 8306,
DOI 10.17487/RFC8306, November 2017,
<https://www.rfc-editor.org/info/rfc8306>.
[RFC8660] Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing with the MPLS Data Plane", RFC 8660,
DOI 10.17487/RFC8660, December 2019,
<https://www.rfc-editor.org/info/rfc8660>.
Authors' Addresses
Balazs Varga (editor)
Ericsson
Magyar Tudosok krt. 11.
Budapest 1117
Hungary
Email: balazs.a.varga@ericsson.com
Janos Farkas
Ericsson
Magyar Tudosok krt. 11.
Budapest 1117
Hungary
Email: janos.farkas@ericsson.com
Lou Berger
LabN Consulting, L.L.C.
Email: lberger@labn.net
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Andrew G. Malis
Malis Consulting
Email: agmalis@gmail.com
Stewart Bryant
Futurewei Technologies
Email: stewart.bryant@gmail.com
Jouni Korhonen
Email: jouni.nospam@gmail.com
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