DetNet B. Varga, Ed.
Internet-Draft J. Farkas
Intended status: Standards Track Ericsson
Expires: June 17, 2021 L. Berger
LabN Consulting, L.L.C.
A. Malis
Malis Consulting
S. Bryant
Futurewei Technologies
December 14, 2020
DetNet Data Plane: MPLS over UDP/IP
draft-ietf-detnet-mpls-over-udp-ip-08
Abstract
This document specifies the MPLS Deterministic Networking data plane
operation and encapsulation over an IP network. The approach is
based on the operation of MPLS-in-UDP technology.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Terms Used in This Document . . . . . . . . . . . . . . . 3
2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 3
2.3. Requirements Language . . . . . . . . . . . . . . . . . . 4
3. DetNet MPLS Operation over DetNet
IP PSNs . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. DetNet Data Plane Procedures . . . . . . . . . . . . . . . . 5
5. Management and Control Information Summary . . . . . . . . . 6
6. Security Considerations . . . . . . . . . . . . . . . . . . . 6
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 7
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
10.1. Normative References . . . . . . . . . . . . . . . . . . 7
10.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
Deterministic Networking (DetNet) is a service that can be offered by
a network to DetNet flows. DetNet provides these flows extremely low
packet loss rates and assured maximum end-to-end delivery latency.
General background and concepts of DetNet can be found in [RFC8655].
To carry DetNet MPLS flows with full functionality at the DetNet
layer over an IP network, the following components are required
(these are a subset of the requirements for MPLS encapsulation listed
in [I-D.ietf-detnet-mpls]):
1. A method for identifying DetNet flows to the processing element.
2. A method for carrying the DetNet sequence number.
3. A method for distinguishing DetNet OAM packets from DetNet data
packets.
4. A method for carrying queueing and forwarding indication.
These requirements are satisfied by the DetNet over MPLS
Encapsulation described in [I-D.ietf-detnet-mpls] and they are partly
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satisfied (i.e., IP flows can be identified however no DetNet
sequence number is carried) by the DetNet IP data plane defined in
[I-D.ietf-detnet-ip]
This document specifies use of the MPLS DetNet encapsulation over an
IP network. The approach is modeled on the operation of MPLS over an
IP Packet Switched Network (PSN) [RFC7510]. It maps the MPLS data
plane encapsulation described in [I-D.ietf-detnet-mpls] to the DetNet
IP data plane defined in [I-D.ietf-detnet-ip].
As specified in [RFC7510]: "MPLS-in-UDP MUST NOT be used over the
general Internet, or over non-cooperating network operators, to carry
traffic that is not congestion controlled." This does apply to
DetNet networks as this document focuses on solutions for networks
that are under a single administrative control or within a closed
group of administrative control.
2. Terminology
2.1. Terms Used in This Document
This document uses the terminology established in the DetNet
architecture [RFC8655], and the reader is assumed to be familiar with
that document and its terminology.
2.2. Abbreviations
The following abbreviations are used in this document:
d-CW A DetNet Control Word (d-CW) is used for sequencing and
identifying duplicate packets of a DetNet flow at the
DetNet service sub-layer.
DetNet Deterministic Networking.
A-Label A special case of an S-Label, whose properties are
known only at the aggregation and deaggregation end-
points.
F-Label A Detnet "forwarding" label that identifies the LSP
used to forward a DetNet flow across an MPLS PSN, e.g.,
a hop-by-hop label used between label switching
routers.
MPLS Multiprotocol Label Switching.
OAM Operations, Administration, and Maintenance.
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PEF Packet Elimination Function.
POF Packet Ordering Function.
PREOF Packet Replication, Elimination and Ordering Functions.
PRF Packet Replication Function.
PSN Packet Switched Network.
S-Label A DetNet "service" label that is used between DetNet
nodes that also implement the DetNet service sub-layer
functions. An S-Label is also used to identify a
DetNet flow at DetNet service sub-layer.
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 Operation over DetNet IP PSNs
This document builds on the specification of MPLS over UDP defined in
[RFC7510]. It may replace partly or entirely the F-Label(s) used in
[I-D.ietf-detnet-mpls] with UDP and IP headers. The UDP and IP
header information is used to identify DetNet flows, including member
flows, per [I-D.ietf-detnet-ip]. The resulting encapsulation is
shown in Figure 1. There may be zero or more F-label(s) between the
S-label and the UDP header.
Note that this encapsulation works equally well with IPv4, IPv6, and
IPv6-based Segment Routing [RFC8754].
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+---------------------------------+
| |
| DetNet App-Flow |
| Payload Packet |
| |
+---------------------------------+ <--\
| DetNet Control Word | |
+---------------------------------+ +--> DetNet data plane
| S-Label | | MPLS encapsulation
+---------------------------------+ |
| [ F-label(s) ] | |
+---------------------------------+ <--+
| UDP Header | |
+---------------------------------+ +--> DetNet data plane
| IP Header | | IP encapsulation
+---------------------------------+ <--/
| Data-Link |
+---------------------------------+
| Physical |
+---------------------------------+
Figure 1: UDP/IP Encapsulation of DetNet MPLS
S-Labels, A-Labels (when present), d-CW and zero or more F-Labels are
used as defined in [I-D.ietf-detnet-mpls] and are not modified by
this document.
4. DetNet Data Plane Procedures
To support outgoing DetNet MPLS over UDP encapsulation, an
implementation MUST support the provisioning of UDP and IP header
information in addition to or in place of F-Label(s). Note, when PRF
is performed at the MPLS service sub-layer, there will be multiple
member flows, and each member flow will require the provisioning of
their own UDP and IP header information. The headers for each
outgoing packet MUST be formatted according to the configuration
information and as defined in [RFC7510], and the UDP Source Port
value MUST be set to uniquely identify the DetNet flow. The packet
MUST then be handled as a DetNet IP packet, per [I-D.ietf-detnet-ip].
This includes QoS related traffic treatment.
To support the receive processing defined in this document, an
implementation MUST also support the provisioning of received UDP and
IP header information. The provisioned information MUST be used to
identify incoming app-flows based on the combination of S-Label and
incoming encapsulation header information. Normal receive processing
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as defined in [I-D.ietf-detnet-mpls], including PEF and POF, can then
take place.
5. Management and Control Information Summary
The following summarizes the minimum set of information that is
needed to configure DetNet MPLS over UDP/IP:
o Label information (A-labels, S-labels and F-labels) to be mapped
to UDP/IP flows. Note that for example, a single S-Label can map
to multiple sets of UDP/IP information when PREOF is used.
o IPv4 or IPv6 source address field.
o IPv4 or IPv6 destination address field.
o DSCP Field in either IPv4 Type of Service or IPv6 Traffic Class
Fields.
o UDP Source Port.
o UDP Destination Port.
o Use/non-use of UDP checksum.
This information MUST be provisioned per DetNet flow via
configuration, e.g., via the controller [RFC8655] or management
plane. Not using the UDP checksum has to be evaluated on a case-by-
case basis for a given network scenario based on the exception
criteria's defined in [RFC7510], particularly when IPv6 is used.
It is the responsibility of the DetNet controller plane to properly
provision both flow identification information and the flow specific
resources needed to provide the traffic treatment needed to meet each
flow's service requirements. This applies for aggregated and
individual flows.
Note: In the presence of network (and port) address translation
devices/functions it would be up to the controller plane to determine
the appropriate information to ensure proper mapping at the sender/
receiver.
6. Security Considerations
The solution defined in this document reuses mechanisms specified in
other documents, and the security considerations in those documents
apply equally to this document. Of particular note is [RFC7510], as
this document is primarily an application of MPLS-in-UDP.
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Additionally, the security considerations of DetNet in general are
discussed in [RFC8655] and [I-D.ietf-detnet-security]. Finally, MPLS
and IP specific security considerations are described in
[I-D.ietf-detnet-mpls] and [I-D.ietf-detnet-ip]. This draft does not
have additional security considerations.
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 and Carlos J.
Bernardos for their various contributions to this work.
9. Contributors
This document is derived from an earlier draft that was edited by
Jouni Korhonen (jouni.nospam@gmail.com) and as such, he contributed
to and authored text in this document.
10. References
10.1. Normative 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-mpls]
Varga, B., Farkas, J., Berger, L., Malis, A., Bryant, S.,
and J. Korhonen, "DetNet Data Plane: MPLS", draft-ietf-
detnet-mpls-13 (work in progress), October 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>.
[RFC7510] Xu, X., Sheth, N., Yong, L., Callon, R., and D. Black,
"Encapsulating MPLS in UDP", RFC 7510,
DOI 10.17487/RFC7510, April 2015,
<https://www.rfc-editor.org/info/rfc7510>.
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[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>.
10.2. Informative References
[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.
[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>.
[RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
(SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
<https://www.rfc-editor.org/info/rfc8754>.
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
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