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. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on June 17, 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 (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 Varga, et al. Expires June 17, 2021 [Page 1] Internet-Draft DetNet MPLS over UDP/IP December 2020 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 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 Varga, et al. Expires June 17, 2021 [Page 2] Internet-Draft DetNet MPLS over UDP/IP December 2020 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. Varga, et al. Expires June 17, 2021 [Page 3] Internet-Draft DetNet MPLS over UDP/IP December 2020 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]. Varga, et al. Expires June 17, 2021 [Page 4] Internet-Draft DetNet MPLS over UDP/IP December 2020 +---------------------------------+ | | | 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 Varga, et al. Expires June 17, 2021 [Page 5] Internet-Draft DetNet MPLS over UDP/IP December 2020 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. Varga, et al. Expires June 17, 2021 [Page 6] Internet-Draft DetNet MPLS over UDP/IP December 2020 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, . [RFC7510] Xu, X., Sheth, N., Yong, L., Callon, R., and D. Black, "Encapsulating MPLS in UDP", RFC 7510, DOI 10.17487/RFC7510, April 2015, . Varga, et al. Expires June 17, 2021 [Page 7] Internet-Draft DetNet MPLS over UDP/IP December 2020 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 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, . [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, . 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 Varga, et al. Expires June 17, 2021 [Page 8] Internet-Draft DetNet MPLS over UDP/IP December 2020 Andrew G. Malis Malis Consulting Email: agmalis@gmail.com Stewart Bryant Futurewei Technologies Email: stewart.bryant@gmail.com Varga, et al. Expires June 17, 2021 [Page 9]