DetNet Working Group G. Mirsky Internet-Draft Ericsson Intended status: Informational M. Chen Expires: 2 February 2024 Huawei D. Black Dell EMC 1 August 2023 Operations, Administration and Maintenance (OAM) for Deterministic Networks (DetNet) with IP Data Plane draft-ietf-detnet-ip-oam-09 Abstract This document defines the principles for using Operations, Administration, and Maintenance protocols and mechanisms in the Deterministic Networking networks with the IP data plane. 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 2 February 2024. Copyright Notice Copyright (c) 2023 IETF Trust and the persons identified as the document authors. All rights reserved. Mirsky, et al. Expires 2 February 2024 [Page 1] Internet-Draft OAM for DetNet over IP August 2023 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions used in this document . . . . . . . . . . . . . . 3 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 3. Active OAM for DetNet Networks with the IP Data Plane . . . . 3 3.1. Mapping Active OAM and IP DetNet flows . . . . . . . . . 4 3.2. Active OAM Using IP-in-UDP Encapsulation . . . . . . . . 5 3.3. Active OAM Using DetNet-in-UDP Encapsulation . . . . . . 5 3.4. Active OAM Using GRE-in-UDP Encapsulation . . . . . . . . 6 4. Active OAM for DetNet IP Interworking with OAM of non-IP DetNet domains . . . . . . . . . . . . . . . . . . . . . . . . . 6 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 6. Security Considerations . . . . . . . . . . . . . . . . . . . 7 7. Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . 7 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 8.1. Normative References . . . . . . . . . . . . . . . . . . 7 8.2. Informational References . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 1. Introduction [RFC8655] introduces and explains Deterministic Networks (DetNet) architecture. Operations, Administration and Maintenance (OAM) protocols are used to detect, localize defects in the network, and monitor network performance. Some OAM functions, e.g., failure detection, work in the network proactively, while others, e.g., defect localization, usually performed on-demand. These tasks achieved by a combination of active and hybrid, as defined in [RFC7799], OAM methods. [I-D.ietf-detnet-oam-framework] lists the functional requirements toward OAM for DetNet domain. The list can further be used for gap analysis of available OAM tools to identify possible enhancements of existing or whether new OAM tools are required to support proactive and on-demand path monitoring and service validation. Also, the document defines the OAM use principals for the DetNet networks with the IP data plane. Mirsky, et al. Expires 2 February 2024 [Page 2] Internet-Draft OAM for DetNet over IP August 2023 2. Conventions used in this document 2.1. Terminology The term "DetNet OAM" used in this document interchangeably with longer version "set of OAM protocols, methods and tools for Deterministic Networks". DetNet Deterministic Networks DiffServ Differentiated Services OAM: Operations, Administration, and Maintenance PREF Packet Replication and Elimination Function POF Packet Ordering Function RDI Remote Defect Indication ICMP Internet Control Message Protocol ACH Associated Channel Header Underlay Network or Underlay Layer: The network that provides connectivity between the DetNet nodes. MPLS network providing LSP connectivity between DetNet nodes is an example of the underlay layer. DetNet Node - a node that is an actor in the DetNet domain. DetNet domain edge node and node that performs PREF within the domain are examples of DetNet node. 3. Active OAM for DetNet Networks with the IP Data Plane OAM protocols and mechanisms act within the data plane of the particular networking layer. And thus it is critical that the data plane encapsulation supports OAM mechanisms in such a way that DetNet OAM packets are in-band with a DetNet flow being monitored, i.e., DetNet OAM test packets follow precisely the same path as DetNet data plane traffic both for unidirectional and bi-directional DetNet paths. The DetNet data plane encapsulation in a transport network with IP encapsulations specified in Section 6 of [RFC8939]. For the IP underlay network, DetNet flows are identified by the ordered match to the provisioned information set that, among other elements, includes the IP protocol, source port number, destination port number. Active Mirsky, et al. Expires 2 February 2024 [Page 3] Internet-Draft OAM for DetNet over IP August 2023 IP OAM protocols like Bidirectional Forwarding Detection (BFD) [RFC5880] or Simple Two-way Active Measurement Protocol (STAMP) [RFC8762], use UDP transport and the well-known UDP port numbers as the destination port. Thus a DetNet node must be able to associate an IP DetNet flow with the particular test session to ensure that test packets experience the same treatment as the DetNet flow packets. For example, that can be achieved with a 3-tuple (destination and source IP addresses in combination with DSCP value) used to identify the IP DetNet flow. In such a scenario, an IP OAM session between the same pair of IP nodes would share the network treatment with the monitored IP DetNet flow regardless of whether ICMP, BFD, or STAMP protocol is used. Most of on-demand failure detection and localization in IP networks is being done by using the Internet Control Message Protocol (ICMP) Echo Request, Echo Reply and the set of defined error messages, e.g., Destination Unreachable, with the more detailed information provided through code points. [RFC0792] and [RFC4443] define the ICMP for IPv4 and IPv6 networks, respectively. Because ICMP is another IP protocol like, for example, UDP, a DetNet node must able to associate an ICMP packet generated by the specified IP DetNet node and addressed to the another IP DetnNet node with an IP DetNet flow between this pair of endpoints. 3.1. Mapping Active OAM and IP DetNet flows IP OAM protocols are used to detect failures (e.g., BFD [RFC5880]) and performance degradation (e.g., STAMP [RFC8762]) that affect an IP DetNet flow. When the UDP destination port number used by the OAM protocol is one of the assigned by IANA, then the UDP source port can be used to achieve co-routedness of OAM, and the monitored IP DetNet flow in the multipath environments, e.g., Link Aggregation Group or Equal Cost Multipath. (That also applies to encapsulation techniques described in Section 3.2 and Section 3.3.) To ensure the accuracy of OAM results in detecting failures and monitoring the performance of IP DetNet, it is essential that test packets not only traverse the same path as the monitored IP DetNet flow but also receive the same treatment by the nodes, e.g., shaping, filtering, policing, and availability of the pre-allocated resources, as experienced by the IP DetNet packet. That correlation between the particular IP OAM protocol session and the monitored IP DetNet flow can be achieved using the DetNet YANG model [I-D.ietf-detnet-yang]. Each IP OAM protocol session is presented as DetNet Application with related service and forwarding sub-layers. The forwarding sub-layer of the IP OAM session is identical to the forwarding sub-layer of the monitored IP DetNet flow, except for information in the grouping ip- header, defined in [I-D.ietf-detnet-yang]. Mirsky, et al. Expires 2 February 2024 [Page 4] Internet-Draft OAM for DetNet over IP August 2023 3.2. Active OAM Using IP-in-UDP Encapsulation As described above, IP active OAM is realized through several protocols. Some protocols use UDP transport, while ICMP is a network-layer protocol. The amount of operational work mapping IP OAM protocols to the monitored DetNet flow can be reduced by using an IP/UDP tunnel to carry IP test packets. Then, to ensure that OAM packets traverse the same set of nodes and links, the IP/UDP tunnel must be mapped to the monitored DetNet flow. Note that the DetNet domain for the test packet is seen as a single IP link in such a case. As a result, transit DetNet IP nodes cannot be traced using the usual traceroute procedure, and a modification of the traceroute may be required. 3.3. Active OAM Using DetNet-in-UDP Encapsulation Active OAM in IP DetNet can be realized using DetNet-in-UDP encapsulation. Using DetNet-in-UDP tunnel between IP DetNet nodes ensures that active OAM test packets are fate-sharing with the monitored IP DetNet flow packets. As a result, a test packet shares the tunnel with the IP DetNet flow and shares the fate, statistically speaking, of the IP DetNet flow being monitored. [I-D.ietf-detnet-mpls-over-ip-preof] describes how DetNet with MPLS over UDP/IP data plane [RFC9025] can be used to support Packet Replication, Elimination, and Ordering Functions to potentially lower packet loss, improve the probability of on-time packet delivery and ensure in-order packet delivery in IP DetNet's service sub-layer. To ensure that an active OAM test packet follows the path of the monitored DetNet flow in the DetNet service sub-layer the encapsulation shown in Figure 1 is used. Mirsky, et al. Expires 2 February 2024 [Page 5] Internet-Draft OAM for DetNet over IP August 2023 +---------------------------------+ | | | DetNet App-Flow | | (original IP) Packet | | | +---------------------------------+ <--\ | DetNet ACH | | +---------------------------------+ +--> PREOF capable | Service-ID (S-Label) | | DetNet IP data +---------------------------------+ | plane encapsulation | UDP Header | | +---------------------------------+ | | IP Header | | +---------------------------------+ <--/ | Data-Link | +---------------------------------+ | Physical | +---------------------------------+ Figure 1: DetNet Associated Channel Header Format where DetNet ACH is the DetNet Associated Channel Header defined in [I-D.ietf-detnet-mpls-oam]. 3.4. Active OAM Using GRE-in-UDP Encapsulation [RFC8086] has defined the method of encapsulating GRE (Generic Routing Encapsulation) headers in UDP. GRE-in-UDP encapsulation can be used for IP DetNet OAM as it eases the task of mapping an OAM test session to a particular IP DetNet flow that is identified by N-tuple. Matching a GRE-in-UDP tunnel to the monitored IP DetNet flow enables the use of Y.1731/G.8013 [ITU-T.1731] as a comprehensive toolset of OAM. The Protocol Type field in GRE header must be set to 0x8902 assigned by IANA to IEEE 802.1ag Connectivity Fault Management (CFM) Protocol / ITU-T Recommendation Y.1731. Y.1731/G.8013 supports necessary for IP DetNet OAM functions, i.e., continuity check, one- way packet loss and packet delay measurement. 4. Active OAM for DetNet IP Interworking with OAM of non-IP DetNet domains A domain in which IP data plane provides DetNet service could be used in conjunction with a TSN and a DetNet domain with MPLS data plane to deliver end-to-end service. In such scenarios, the ability to detect defects and monitor performance using OAM is essential. [I-D.ietf-detnet-mpls-oam] identified two OAM interworking models - peering and tunneling. Interworking between DetNet domains with IP and MPLS data planes analyzed in Section 6.2 of Mirsky, et al. Expires 2 February 2024 [Page 6] Internet-Draft OAM for DetNet over IP August 2023 [I-D.ietf-detnet-mpls-oam]. Also, requirements and recommendations for OAM interworking between a DetNet domain with MPLS data plane and OAM of a TSN equally apply to a DetNet domain with an IP data plane. 5. IANA Considerations This document does not have any requests for IANA allocation. This section can be deleted before the publication of the draft. 6. Security Considerations This document describes the applicability of the existing Fault Management and Performance Monitoring IP OAM protocols, and does not raise any security concerns or issues in addition to ones common to networking or already documented for the referenced DetNet and OAM protocols. 7. Acknowledgment TBA 8. References 8.1. Normative References [I-D.ietf-detnet-mpls-oam] Mirsky, G., Chen, M., and B. Varga, "Operations, Administration and Maintenance (OAM) for Deterministic Networks (DetNet) with MPLS Data Plane", Work in Progress, Internet-Draft, draft-ietf-detnet-mpls-oam-13, 6 July 2023, . [I-D.ietf-detnet-yang] Geng, X., Ryoo, Y., Fedyk, D., Rahman, R., and Z. Li, "Deterministic Networking (DetNet) YANG Model", Work in Progress, Internet-Draft, draft-ietf-detnet-yang-18, 10 July 2023, . [RFC0792] Postel, J., "Internet Control Message Protocol", STD 5, RFC 792, DOI 10.17487/RFC0792, September 1981, . Mirsky, et al. Expires 2 February 2024 [Page 7] Internet-Draft OAM for DetNet over IP August 2023 [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", STD 89, RFC 4443, DOI 10.17487/RFC4443, March 2006, . [RFC8086] Yong, L., Ed., Crabbe, E., Xu, X., and T. Herbert, "GRE- in-UDP Encapsulation", RFC 8086, DOI 10.17487/RFC8086, March 2017, . [RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas, "Deterministic Networking Architecture", RFC 8655, DOI 10.17487/RFC8655, October 2019, . [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, . [RFC9025] Varga, B., Ed., Farkas, J., Berger, L., Malis, A., and S. Bryant, "Deterministic Networking (DetNet) Data Plane: MPLS over UDP/IP", RFC 9025, DOI 10.17487/RFC9025, April 2021, . 8.2. Informational References [I-D.ietf-detnet-mpls-over-ip-preof] Varga, B., Farkas, J., and A. G. Malis, "Deterministic Networking (DetNet): DetNet PREOF via MPLS over UDP/IP", Work in Progress, Internet-Draft, draft-ietf-detnet-mpls- over-ip-preof-07, 25 July 2023, . [I-D.ietf-detnet-oam-framework] Mirsky, G., Theoleyre, F., Papadopoulos, G. Z., Bernardos, C. J., Varga, B., and J. Farkas, "Framework of Operations, Administration and Maintenance (OAM) for Deterministic Networking (DetNet)", Work in Progress, Internet-Draft, draft-ietf-detnet-oam-framework-08, 1 February 2023, . [ITU-T.1731] ITU-T, "Operations, administration and maintenance (OAM) functions and mechanisms for Ethernet-based networks", ITU-T G.8013/Y.1731, August 2015. Mirsky, et al. Expires 2 February 2024 [Page 8] Internet-Draft OAM for DetNet over IP August 2023 [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, . [RFC7799] Morton, A., "Active and Passive Metrics and Methods (with Hybrid Types In-Between)", RFC 7799, DOI 10.17487/RFC7799, May 2016, . [RFC8762] Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple Two-Way Active Measurement Protocol", RFC 8762, DOI 10.17487/RFC8762, March 2020, . Authors' Addresses Greg Mirsky Ericsson Email: gregimirsky@gmail.com Mach(Guoyi) Chen Huawei Email: mach.chen@huawei.com David Black Dell EMC 176 South Street Hopkinton, MA, 01748 United States of America Email: david.black@dell.com Mirsky, et al. Expires 2 February 2024 [Page 9]