idnits 2.17.1 draft-bryant-mpls-sfl-framework-04.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (April 25, 2017) is 2558 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Outdated reference: A later version (-07) exists of draft-ietf-mpls-flow-ident-04 Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 MPLS Working Group S. Bryant 3 Internet-Draft M. Chen 4 Intended status: Informational Z. Li 5 Expires: October 27, 2017 Huawei 6 G. Swallow 7 S. Sivabalan 8 Cisco Systems 9 G. Mirsky 10 Ericsson 11 April 25, 2017 13 Synonymous Flow Label Framework 14 draft-bryant-mpls-sfl-framework-04 16 Abstract 18 draft-ietf-mpls-flow-ident describes the requirement for introducing 19 flow identities within the MPLS architecture. This document 20 describes a method of accomplishing this by using a technique called 21 Synonymous Flow Labels in which labels which mimic the behaviour of 22 other labels provide the identification service. These identifiers 23 can be used to trigger per-flow operations on the on the packet at 24 the receiving label switching router. 26 Status of This Memo 28 This Internet-Draft is submitted in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF). Note that other groups may also distribute 33 working documents as Internet-Drafts. The list of current Internet- 34 Drafts is at http://datatracker.ietf.org/drafts/current/. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 This Internet-Draft will expire on October 27, 2017. 43 Copyright Notice 45 Copyright (c) 2017 IETF Trust and the persons identified as the 46 document authors. All rights reserved. 48 This document is subject to BCP 78 and the IETF Trust's Legal 49 Provisions Relating to IETF Documents 50 (http://trustee.ietf.org/license-info) in effect on the date of 51 publication of this document. Please review these documents 52 carefully, as they describe your rights and restrictions with respect 53 to this document. Code Components extracted from this document must 54 include Simplified BSD License text as described in Section 4.e of 55 the Trust Legal Provisions and are provided without warranty as 56 described in the Simplified BSD License. 58 Table of Contents 60 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 61 2. Synonymous Flow Labels . . . . . . . . . . . . . . . . . . . 2 62 3. User Service Traffic in the Data Plane . . . . . . . . . . . 3 63 3.1. Applications Label Present . . . . . . . . . . . . . . . 4 64 3.1.1. Setting TTL and the Traffic Class Bits . . . . . . . 4 65 3.2. Single Label Stack . . . . . . . . . . . . . . . . . . . 4 66 3.2.1. Setting TTL and the Traffic Class Bits . . . . . . . 6 67 3.3. Aggregation of SFL Actions . . . . . . . . . . . . . . . 6 68 4. Equal Cost Multipath Considerations . . . . . . . . . . . . . 7 69 5. Privacy Considerations . . . . . . . . . . . . . . . . . . . 7 70 6. Security Considerations . . . . . . . . . . . . . . . . . . . 7 71 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 72 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 73 8.1. Normative References . . . . . . . . . . . . . . . . . . 8 74 8.2. Informative References . . . . . . . . . . . . . . . . . 8 75 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 77 1. Introduction 79 [I-D.ietf-mpls-flow-ident] describes the requirement for introducing 80 flow identities within the MPLS architecture. 82 This document describes a method of accomplishing this by using a 83 technique called Synonymous Flow Labels (SFL) (see (Section 2)) in 84 which labels which mimic the behaviour of other labels provide the 85 identification service. These identifiers can be used to trigger 86 per-flow operations on the packet at the receiving label switching 87 router. 89 2. Synonymous Flow Labels 91 An SFL is defined to be a label that causes exactly the same 92 behaviour at the egress Label Switching Router (LSR) as the label it 93 replaces, but in addition also causes an agreed action to take place 94 on the packet. There are many possible additional actions such as 95 the measurement of the number of received packets in a flow, 96 triggering IPFIX inspection, triggering other types of Deep Packet 97 Inspection, or identification of the packet source. In, for example, 98 a Performance Monitoring (PM) application, the agreed action could be 99 the recording of the receipt of the packet by incrementing a packet 100 counter. This is a natural action in many MPLS implementations, and 101 where supported this permits the implementation of high quality 102 packet loss measurement without any change to the packet forwarding 103 system. 105 Consider an MPLS application such as a pseudowire (PW), and consider 106 that it is desired to use the approach specified in this document to 107 make a packet loss measurement. By some method outside the scope of 108 this text, two labels, synonymous with the PW labels are obtained 109 from the egress terminating provider edge (T-PE). By alternating 110 between these SFLs and using them in place of the PW label, the PW 111 packets may be batched for counting without any impact on the PW 112 forwarding behaviour (note that strictly only one SFL is needed in 113 this application, but that is an optimization that is a matter for 114 the implementor). 116 Now consider an MPLS application that is multi-point to point such as 117 a VPN. Here it is necessary to identify a packet batch from a 118 specific source. This is achieved by making the SFLs source 119 specific, so that batches from one source are marked differently from 120 batches from another source. The sources all operate independently 121 and asynchronously from each other, independently co-ordinating with 122 the destination. Each ingress is thus able to establish its own SFL 123 to identify the sub-flow and thus enable PM per flow. 125 Finally we need to consider the case where there is no MPLS 126 application label such as occurs when sending IP over an LSP. In 127 this case introducing an SFL that was synonymous with the LSP label 128 would introduce network wide forwarding state. This would not be 129 acceptable for scaling reasons. We therefore have no choice but to 130 introduce an additional label. Where penultimate hop popping (PHP) 131 is in use, the semantics of this additional label can be similar to 132 the LSP label. Where PHP is not in use, the semantics are similar to 133 an MPLS explicit NULL. In both of these cases the label has the 134 additional semantics of the SFL. 136 Note that to achieve the goals set out in Section 1 SFLs need to be 137 allocated from the platform label table. 139 3. User Service Traffic in the Data Plane 141 As noted in Section 2 it is necessary to consider two cases: 143 1. Applications label present 144 2. Single label stack 146 3.1. Applications Label Present 148 Figure 1 shows the case in which both an LSP label and an application 149 label are present in the MPLS label stack. Traffic with no SFL 150 function present runs over the "normal" stack, and SFL enabled flows 151 run over the SFL stack with the SFL used to indicate the packet 152 batch. 154 +-----------------+ +-----------------+ 155 | | | | 156 | LSP | | LSP | . 337 8.2. Informative References 339 [I-D.ietf-mpls-flow-ident] 340 Bryant, S., Pignataro, C., Chen, M., Li, Z., and G. 341 Mirsky, "MPLS Flow Identification Considerations", draft- 342 ietf-mpls-flow-ident-04 (work in progress), February 2017. 344 [RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay 345 Measurement for MPLS Networks", RFC 6374, 346 DOI 10.17487/RFC6374, September 2011, 347 . 349 [RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and 350 L. Yong, "The Use of Entropy Labels in MPLS Forwarding", 351 RFC 6790, DOI 10.17487/RFC6790, November 2012, 352 . 354 [RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an 355 Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May 356 2014, . 358 Authors' Addresses 360 Stewart Bryant 361 Huawei 363 Email: stewart.bryant@gmail.com 365 Mach Chen 366 Huawei 368 Email: mach.chen@huawei.com 370 Zhenbin Li 371 Huawei 373 Email: lizhenbin@huawei.com 374 George Swallow 375 Cisco Systems 377 Email: swallow@cisco.com 379 Siva Sivabalan 380 Cisco Systems 382 Email: msiva@cisco.com 384 Gregory Mirsky 385 Ericsson 387 Email: gregory.mirsky@eicsson.com