MPLS Working Group W. Cheng Internet-Draft China Mobile Intended status: Standards Track X. Min Expires: May 5, 2020 ZTE T. Zhou Huawei X. Dong FiberHome Y. Peleg Broadcom November 2, 2019 Encapsulation For MPLS Performance Measurement with Alternate Marking Method draft-cheng-mpls-inband-pm-encapsulation-02 Abstract This document defines the encapsulation for MPLS performance measurement with alternate marking method, which performs flow-based packet loss, delay, and jitter measurements on live traffic. 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/. 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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 1.1. Conventions Used in This Document . . . . . . . . . . . . 3 1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 3 1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3 2. Flow-based PM Encapsulation in MPLS . . . . . . . . . . . . . 3 2.1. Examples for Applying Flow-ID in a label stack . . . . . 4 3. Procedures of Encapsulation, Look-up and Decapsulation . . . 7 4. Procedures of Flow-ID allocation . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 8.1. Normative References . . . . . . . . . . . . . . . . . . 9 8.2. Informative References . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 1. Introduction [I-D.fioccola-spring-flow-label-alt-mark] describes how the alternate marking method can be used as the passive performance measurement method in an IPv6 domain, actually the alternate marking method can also be applied to an MPLS domain, and what's missed is the encapsulation for MPLS performance measurement with alternate marking method. [RFC8372] discusses the desired capabilities for MPLS flow identification, in order to perform a better in-band performance monitoring of user data packets. Synonymous Flow Label (SFL), which is introduced in [I-D.ietf-mpls-sfl-framework], is identified as a method of accomplishing MPLS flow identification. This document employs a method, other than SFL, to accomplish MPLS flow identification. The method described in this document is simple and flexible, furthermore, it complies with the current MPLS forwarding paradigm. The method described in this document is complementary to the SFL method, the former targets at hop-by-hop performance measurement, and the latter targets at end-to-end performance measurement, furthermore, the former supports the application scenario where Flow- Cheng, et al. Expires May 5, 2020 [Page 2] Internet-Draft Encap For MPLS PM with AMM November 2019 ID is applied to MPLS LSP and MPLS VPN synchronously, and the latter doesn't support this kind of application scenario. This document defines the encapsulation for MPLS performance measurement with alternate marking method, which performs flow-based packet loss, delay, and jitter measurements on live traffic. 1.1. Conventions Used in This Document 1.1.1. Terminology LSP: Label Switched Path MPLS: Multi-Protocol Label Switching NMS: Network Management System PM: Performance Measurement PW: PseudoWire SFL: Synonymous Flow Label TC: Traffic Class TTL: Time to Live VC: Virtual Channel VPN: Virtual Private Network 1.1.2. 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. 2. Flow-based PM Encapsulation in MPLS Flow-based MPLS performance measurement encapsulation with alternate marking method has the following format: Cheng, et al. Expires May 5, 2020 [Page 3] Internet-Draft Encap For MPLS PM with AMM November 2019 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flow-ID Indicator Label (TBA1) | TC |S| TTL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flow-ID |L|D|R|S| Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ Payload ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: Flow-based PM Encapsulation in MPLS Where Flow-ID Indicator Label is defined in this document as value TBA1, and the other fields related to the Flow-based PM encapsulation are defined as follows: o Flow-ID - an MPLS label value used as MPLS flow identification [RFC8372], it should be unique within the administrative domain. Flow-ID values can be allocated by an external NMS or a controller, based on measurement object instance such as LSP and PW. There is a one-to-one mapping between Flow-ID and flow. The specific method on how to allocate the Flow-ID values is described in Section 4. Note that the Flow-ID Label can be placed either at the bottom of the MPLS label stack or not, and the Flow-ID Indicator Label MAY appear multiple times in a label stack, which means more than one Flow-ID can be present within an MPLS label stack. Section 2.1 of this document provides several examples to illustrate how to apply Flow-ID in a label stack. o L and D - L(oss) bit and D(elay) bit are used for coloring the packets (called double-marking methodology), which is required by the alternate marking method. o R - R bit is reserved for future use and MUST be set to zero. o Reserved - one octet long field reserved for future use and MUST be set to zero. 2.1. Examples for Applying Flow-ID in a label stack Three examples on different layout of Flow-ID label (4 octets) are illustrated as follows: (1) Layout of Flow-ID label when applied to MPLS LSP. Cheng, et al. Expires May 5, 2020 [Page 4] Internet-Draft Encap For MPLS PM with AMM November 2019 +----------------------+ | | | LSP | | Label | +----------------------+ | | | Flow-ID Indicator | | Label | +----------------------+ | | | Flow-ID | | Label | +----------------------+ | | | VPN | | Label | +----------------------+ <= Bottom of stack | | | Payload | | | +----------------------+ Figure 2: Applying Flow-ID to MPLS LSP (2) Layout of Flow-ID label when applied to MPLS VPN traffic. Cheng, et al. Expires May 5, 2020 [Page 5] Internet-Draft Encap For MPLS PM with AMM November 2019 +----------------------+ | | | LSP | | Label | +----------------------+ | | | VPN | | Label | +----------------------+ | | | Flow-ID Indicator | | Label | +----------------------+ | | | Flow-ID | | Label | +----------------------+ <= Bottom of stack | | | Payload | | | +----------------------+ Figure 3: Applying Flow-ID to MPLS VPN (3) Layout of Flow-ID label when applied to both MPLS LSP and MPLS VPN traffic. Cheng, et al. Expires May 5, 2020 [Page 6] Internet-Draft Encap For MPLS PM with AMM November 2019 +----------------------+ | | | LSP | | Label | +----------------------+ | | | Flow-ID Indicator | | Label | +----------------------+ | | | Flow-ID | | Label | +----------------------+ | | | VPN | | Label | +----------------------+ | | | Flow-ID Indicator | | Label | +----------------------+ | | | Flow-ID | | Label | +----------------------+ <= Bottom of stack | | | Payload | | | +----------------------+ Figure 4: Applying Flow-ID to both MPLS LSP and MPLS VPN Note that here VPN label can be MPLS PW label, MPLS Ethernet VPN label or MPLS IP VPN label, and it's also called VC label as defined in [RFC4026]. Also note that for this example the two Flow-ID values appearing in a label stack MUST be different, that is to say, Flow-ID applied to MPLS LSP and Flow-ID applied to MPLS VPN share the same value space. 3. Procedures of Encapsulation, Look-up and Decapsulation The procedures for Flow-ID label encapsulation, look-up and decapsulation are summarized as follows: o The ingress node inserts the Flow-ID Indicator Label, alongside with the Flow-ID label, into the MPLS label stack. At the same Cheng, et al. Expires May 5, 2020 [Page 7] Internet-Draft Encap For MPLS PM with AMM November 2019 time, the ingress node sets the L bit and D bit, as needed by alternate-marking technique, and sets the Flow-ID value, as defined in this document. o The transit nodes look up the Flow-ID label with the help of the Flow-ID Indicator Label, and transmit the collected information to an external NMS or a controller, which includes the values of the block counters and the timestamps of the marked packets, along with the value of the Flow-ID, referring to the procedures of alternate marking method. o The egress node pops the Flow-ID Indicator Label, alongside with the Flow-ID label, from the MPLS label stack. This document doesn't introduce any new procedure regarding to the process of the decapsulated packet. 4. Procedures of Flow-ID allocation There are two ways of allocating Flow-ID, one way is to allocate Flow-ID by manual trigger from the network operator, and the other way is to allocate Flow-ID by automatic trigger from the ingress node, details are as follows: o In the case of manual trigger, the network operator would manually input the characteristics (e.g. IP five tuples and IP DSCP) of the measured IP traffic flow, then the NMS or the controller would generate one or two Flow-IDs based on the input from the network operator, and provision the ingress node with the characteristics of the measured IP traffic flow and the corresponding allocated Flow-ID(s). o In the case of automatic trigger, the ingress node would identify the IP traffic flow entering the measured path, export the characteristics of the identified IP traffic flow to the NMS or the controller by IPFIX [RFC7011], then the NMS or the controller would generate one or two Flow-IDs based on the export from the ingress node, and provision the ingress node with the characteristics of the identified IP traffic flow and the corresponding allocated Flow-ID(s). The policy pre-configured at the NMS or the controller decides whether one Flow-ID or two Flow-IDs would be generated. If the performance measurement on VPN traffic is enabled, then one Flow-ID applied to MPLS VPN would be generated; if the performance measurement on LSP tunnel is enabled, then one Flow-ID applied to MPLS LSP would be generated; if both of them are enabled, then two Flow-IDs respectively applied to MPLS VPN and MPLS LSP would be generated. Cheng, et al. Expires May 5, 2020 [Page 8] Internet-Draft Encap For MPLS PM with AMM November 2019 Whether using manual trigger or using automatic trigger, the NMS or the controller MUST guarantee every generated Flow-ID is unique within the administrative domain. 5. Security Considerations This document does not introduce additional security requirements and mechanisms. 6. IANA Considerations In the Special-Purpose MPLS Label Values registry defined in [SP-MPLS-Label], a new Special-Purpose MPLS Label Value for Flow-ID Indicator is requested from IANA as follows: +---------------------+-----------------+---------------+-----------+ | Special-Purpose | Description | Semantics | Reference | | MPLS Label Value | | Definition | | +---------------------+-----------------+---------------+-----------+ | TBA1 | Flow-ID | Section 2 | This | | | Indicator Label | | Document | +---------------------+-----------------+---------------+-----------+ Table 1: New Special-Purpose MPLS Label Value for Flow-ID Indicator 7. Acknowledgements The authors would like to acknowledge Greg Mirsky, Aihua Liu, Shuangping Zhan and Ming Ke for their careful review and very helpful comments. 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, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [SP-MPLS-Label] "Special-Purpose MPLS Label Values", 2014, . Cheng, et al. Expires May 5, 2020 [Page 9] Internet-Draft Encap For MPLS PM with AMM November 2019 8.2. Informative References [I-D.fioccola-spring-flow-label-alt-mark] Fioccola, G., Velde, G., Cociglio, M., and P. Muley, "Using the IPv6 Flow Label for Performance Measurement with Alternate Marking Method in Segment Routing", draft- fioccola-spring-flow-label-alt-mark-01 (work in progress), October 2017. [I-D.ietf-mpls-sfl-framework] Bryant, S., Chen, M., Li, Z., Swallow, G., Sivabalan, S., and G. Mirsky, "Synonymous Flow Label Framework", draft- ietf-mpls-sfl-framework-06 (work in progress), October 2019. [RFC4026] Andersson, L. and T. Madsen, "Provider Provisioned Virtual Private Network (VPN) Terminology", RFC 4026, DOI 10.17487/RFC4026, March 2005, . [RFC7011] Claise, B., Ed., Trammell, B., Ed., and P. Aitken, "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of Flow Information", STD 77, RFC 7011, DOI 10.17487/RFC7011, September 2013, . [RFC8372] Bryant, S., Pignataro, C., Chen, M., Li, Z., and G. Mirsky, "MPLS Flow Identification Considerations", RFC 8372, DOI 10.17487/RFC8372, May 2018, . Authors' Addresses Weiqiang Cheng China Mobile Beijing China Email: chengweiqiang@chinamobile.com Xiao Min ZTE Nanjing China Email: xiao.min2@zte.com.cn Cheng, et al. Expires May 5, 2020 [Page 10] Internet-Draft Encap For MPLS PM with AMM November 2019 Tianran Zhou Huawei Beijing China Email: zhoutianran@huawei.com Ximing Dong FiberHome Wuhan China Email: dxm@fiberhome.com Yoav Peleg Broadcom USA Email: yoav.peleg@broadcom.com Cheng, et al. Expires May 5, 2020 [Page 11]