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diff --git a/doc/rfc/rfc9025.txt b/doc/rfc/rfc9025.txt new file mode 100644 index 0000000..320bc55 --- /dev/null +++ b/doc/rfc/rfc9025.txt @@ -0,0 +1,382 @@ + + + + +Internet Engineering Task Force (IETF) B. Varga, Ed. +Request for Comments: 9025 J. Farkas +Category: Standards Track Ericsson +ISSN: 2070-1721 L. Berger + LabN Consulting, L.L.C. + A. Malis + Malis Consulting + S. Bryant + Futurewei Technologies + April 2021 + + + Deterministic Networking (DetNet) Data Plane: MPLS over UDP/IP + +Abstract + + This document specifies the MPLS Deterministic Networking (DetNet) + data plane operation and encapsulation over an IP network. The + approach is based on the operation of MPLS-over-UDP technology. + +Status of This Memo + + This is an Internet Standards Track document. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + Internet Standards is available in Section 2 of RFC 7841. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + https://www.rfc-editor.org/info/rfc9025. + +Copyright Notice + + Copyright (c) 2021 IETF Trust and the persons identified as the + document authors. All rights reserved. + + This document is subject to BCP 78 and the IETF Trust's Legal + Provisions Relating to IETF Documents + (https://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + +Table of Contents + + 1. Introduction + 2. Terminology + 2.1. Terms Used in This Document + 2.2. Abbreviations + 2.3. Requirements Language + 3. DetNet MPLS Operation over DetNet IP PSNs + 4. DetNet Data Plane Procedures + 5. Management and Control Information Summary + 6. Security Considerations + 7. IANA Considerations + 8. References + 8.1. Normative References + 8.2. Informative References + Acknowledgements + Contributors + Authors' Addresses + +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 [RFC8964]): + + 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 Operations, Administration, + and Maintenance (OAM) packets from DetNet data packets. + + 4. A method for carrying queuing and forwarding indication. + + These requirements are satisfied by the DetNet over MPLS + Encapsulation described in [RFC8964] and they are partly satisfied + (i.e., IP flows can be identified; however, no DetNet sequence number + is carried) by the DetNet IP data plane defined in [RFC8939]. + + 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) using UDP encapsulation [RFC7510]. + It maps the MPLS data plane encapsulation described in [RFC8964] to + the DetNet IP data plane defined in [RFC8939]. + + [RFC7510] specifies that "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 constraint does + apply to the use of RFC 7510 in a DetNet network because DetNet is + constrained to operate within 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]; 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 + + DSCP Differentiated Services Code Point + + A-Label A special case of an S-Label, whose properties are + known only at the aggregation and deaggregation + endpoints. + + 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 + + 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 the 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 partly or entirely replace the F-Label(s) used in + [RFC8964] with UDP and IP headers. The UDP and IP header information + is used to identify DetNet flows, including member flows, per + [RFC8939]. The resulting encapsulation is shown in Figure 1. There + may be zero or more F-Labels between the S-Label and the UDP header. + + Note that this encapsulation works equally well with IPv4, IPv6, and + IPv6-based Segment Routing [RFC8754]. + + +---------------------------------+ + | | + | 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 [RFC8964] 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 the + 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 [RFC8939]. + 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 + as defined in [RFC8964], 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: + + * 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. + + * IPv4 or IPv6 source address field + + * IPv4 or IPv6 destination address field + + * DSCP Field in either IPv4 Type of Service or IPv6 Traffic Class + Fields + + * UDP Source Port + + * UDP Destination Port + + * 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 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 both 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-over-UDP. + Additionally, the security considerations of DetNet in general are + discussed in [RFC8655] and [DETNET-SECURITY]. Finally, MPLS- and IP- + specific security considerations are described in [RFC8964] and + [RFC8939]. This document does not have additional security + considerations. + +7. IANA Considerations + + This document has no IANA actions. + +8. References + +8.1. Normative References + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, + DOI 10.17487/RFC2119, March 1997, + <https://www.rfc-editor.org/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>. + + [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>. + + [RFC8939] Varga, B., Ed., Farkas, J., Berger, L., Fedyk, D., and S. + Bryant, "Deterministic Networking (DetNet) Data Plane: + IP", RFC 8939, DOI 10.17487/RFC8939, November 2020, + <https://www.rfc-editor.org/info/rfc8939>. + + [RFC8964] Varga, B., Ed., Farkas, J., Berger, L., Malis, A., Bryant, + S., and J. Korhonen, "Deterministic Networking (DetNet) + Data Plane: MPLS", RFC 8964, DOI 10.17487/RFC8964, January + 2021, <https://www.rfc-editor.org/info/rfc8964>. + +8.2. Informative References + + [DETNET-SECURITY] + Grossman, E., Ed., Mizrahi, T., and A. J. Hacker, + "Deterministic Networking (DetNet) Security + Considerations", Work in Progress, Internet-Draft, draft- + ietf-detnet-security-16, 22 February 2021, + <https://tools.ietf.org/html/draft-ietf-detnet-security- + 16>. + + [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>. + +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. + +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. + +Authors' Addresses + + Balázs Varga (editor) + Ericsson + Budapest + Magyar Tudosok krt. 11. + 1117 + Hungary + + Email: balazs.a.varga@ericsson.com + + + János Farkas + Ericsson + Budapest + Magyar Tudosok krt. 11. + 1117 + Hungary + + Email: janos.farkas@ericsson.com + + + Lou Berger + LabN Consulting, L.L.C. + + Email: lberger@labn.net + + + Andrew G. Malis + Malis Consulting + + Email: agmalis@gmail.com + + + Stewart Bryant + Futurewei Technologies + + Email: sb@stewartbryant.com |