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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'IEEE802.1Qav' is mentioned on line 182, but not defined == Missing Reference: 'IEEE802.1Qbv' is mentioned on line 193, but not defined == Missing Reference: 'IEEE802.1Qch' is mentioned on line 194, but not defined == Outdated reference: A later version (-07) exists of draft-ietf-detnet-ip-03 == Outdated reference: A later version (-13) exists of draft-ietf-detnet-mpls-03 ** Downref: Normative reference to an Informational RFC: RFC 4594 Summary: 1 error (**), 0 flaws (~~), 6 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 DeNet WG Q. Xiong 3 Internet-Draft J. Yu 4 Intended status: Standards Track ZTE Corporation 5 Expires: May 4, 2020 P. Liu 6 F. Qin 7 China Mobile 8 November 1, 2019 10 DetNet QoS Policy 11 draft-xiong-detnet-qos-policy-02 13 Abstract 15 This document proposes a Quality of Service (QoS) policy to apply 16 Differentiated Services (DiffServ) model for Deterministic Networking 17 (DetNet) and defines a DetNet DiffServ mechanism including DetNet IP 18 and MPLS encapsulation. 20 Status of This Memo 22 This Internet-Draft is submitted in full conformance with the 23 provisions of BCP 78 and BCP 79. 25 Internet-Drafts are working documents of the Internet Engineering 26 Task Force (IETF). Note that other groups may also distribute 27 working documents as Internet-Drafts. The list of current Internet- 28 Drafts is at https://datatracker.ietf.org/drafts/current/. 30 Internet-Drafts are draft documents valid for a maximum of six months 31 and may be updated, replaced, or obsoleted by other documents at any 32 time. It is inappropriate to use Internet-Drafts as reference 33 material or to cite them other than as "work in progress." 35 This Internet-Draft will expire on May 4, 2020. 37 Copyright Notice 39 Copyright (c) 2019 IETF Trust and the persons identified as the 40 document authors. All rights reserved. 42 This document is subject to BCP 78 and the IETF Trust's Legal 43 Provisions Relating to IETF Documents 44 (https://trustee.ietf.org/license-info) in effect on the date of 45 publication of this document. Please review these documents 46 carefully, as they describe your rights and restrictions with respect 47 to this document. Code Components extracted from this document must 48 include Simplified BSD License text as described in Section 4.e of 49 the Trust Legal Provisions and are provided without warranty as 50 described in the Simplified BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 55 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 56 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 57 2. DetNet DiffServ Overview . . . . . . . . . . . . . . . . . . 3 58 2.1. DetNet Classifiers . . . . . . . . . . . . . . . . . . . 4 59 2.2. DetNet Traffic Conditioners . . . . . . . . . . . . . . . 4 60 2.2.1. Scheduler . . . . . . . . . . . . . . . . . . . . . . 5 61 2.2.2. Order . . . . . . . . . . . . . . . . . . . . . . . . 5 62 2.3. DetNet DSCP . . . . . . . . . . . . . . . . . . . . . . . 5 63 2.4. DetNet PHB . . . . . . . . . . . . . . . . . . . . . . . 5 64 2.5. DetNet Queuing . . . . . . . . . . . . . . . . . . . . . 6 65 3. DetNet IP DiffServ Consideration . . . . . . . . . . . . . . 6 66 4. DetNet MPLS DiffServ Consideration . . . . . . . . . . . . . 6 67 5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 68 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 69 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 70 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 71 8.1. Informative References . . . . . . . . . . . . . . . . . 7 72 8.2. Normative References . . . . . . . . . . . . . . . . . . 7 73 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 75 1. Introduction 77 As defined in [RFC8655], Deterministic Networking (DetNet) provides a 78 capability to carry specified unicast or multicast data flows for 79 real-time applications with extremely low data loss rates and bounded 80 latency. DetNet and non-DetNet packets may be allowed to transmitted 81 in the same network and more than one DetNet flows which has 82 different priorities may be forwarded through the DetNet domain. The 83 DetNet Class of Service (CoS) should be taken into consideration to 84 provide Quality of Service (QoS) for DetNet services. 86 As discussed in [I-D.ietf-detnet-mpls] and [I-D.ietf-detnet-ip], 87 Differentiated Services (DiffServ) can provide traffic forwarding 88 treatment for DetNet networks. The DiffServ architecture as 89 specified in [RFC2475] defined a model that traffic entering a 90 DiffServ domain is classified and conditioned at the boundaries and 91 marked with a DiffServ Code Point (DSCP) defined in [RFC2474]. The 92 DSCP is used at transit nodes to select the Per Hop Behavior (PHB) 93 that determines the scheduling treatment. And [RFC3270] provide a 94 solution to support DiffServ for traffic marked with Traffic Class 95 (TC) [RFC5462] transported over an MPLS network. 97 This document proposes a QoS policy to apply DiffServ model for 98 DetNet networks and defines a DetNet DiffServ mechanism including 99 DetNet IP and MPLS encapsulation. 101 1.1. Requirements Language 103 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 104 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 105 document are to be interpreted as described in [RFC2119]. 107 1.2. Terminology 109 The terminology is defined as [RFC8655], [RFC3270], [RFC2475] and 110 [RFC2474]. 112 2. DetNet DiffServ Overview 114 The DetNet network needs to be capable of supporting differentiated 115 services dividing to one or more contiguous DiffServ domains. The 116 key components within a DiffServ domain including traffic 117 classification and conditioning functions, and PHB-based forwarding. 118 The customers may specify packet classification policy, traffic 119 profiles and actions to DetNet flows which are in-profile or out-of- 120 profile at the boundary. The DiffServ domains may support different 121 PHB groups internally and different codepoint->PHB mappings at the 122 transit nodes. The DetNet DiffServ process for packets is as 123 Figure 1 shown. 125 +---------+ 126 | Meter |-----------------------------------+ 127 +----->| (DetNet |------------------+ | 128 | | Profile)|--+ | | 129 | +---------+ | | | 130 | V V V 131 DetNet+------------+ +----------+ +------------+ +---------+ 132 Flow | Classifier | | Marker | |Shaper/Order| | Queuing | 133 =====>| (DetNet |====>| (DetNet |====>| Dropper/ |====>| (DetNet | 134 | BA/MF) | | DSCP) | | Scheduler/ | | PHB) | 135 +------------+ +----------+ +------------+ +---------+ 137 Figure 1: Overview of a DetNet DiffServ mechanism 139 2.1. DetNet Classifiers 141 As defined in [RFC2475], packet classifiers select packets in a 142 traffic stream based on the information of packet header including 143 two types of classifiers, the BA (Behavior Aggregate) and MF (Multi- 144 Field) Classifier. The difference is that the BA classifies packets 145 based on the CoS field and the latter one based on more other header 146 fields. 148 In DetNet DiffServ model, BA and MF can be applied for packets 149 classification. After classification, the flows can be seperated 150 from DetNet and non-DetNet. As specified in [I-D.ietf-detnet-ip], no 151 DetNet specific encapsulation is defined to support DetNet IP flow 152 identification and DetNet service delivery. So the DetNet IP 153 classifiers is the same as defined in [RFC2474] and [RFC2475]. As 154 defined in [I-D.ietf-detnet-mpls], DetNet service Label (S-Label) is 155 used to identify a DetNet flow and forwarding labels (F-Labels) are 156 used to provide LSP-based connectivity in DetNet MPLS header. The 157 S-Label and F-Labels can be used in combination with MPLS TC filed in 158 MF classifier. And DetNet MPLS BA classifier select packets based on 159 the MPLS TC field only as defined in [RFC5462]. 161 2.2. DetNet Traffic Conditioners 163 As mentioned in [RFC8655], DetNet flows can be shaped or scheduled. 164 The rate limiting of DetNet traffic and the starvation avoiding of 165 non-DetNet traffic, e.g., at the ingress of the DetNet domain must be 166 applied by traffic policing and shaping functions. As [RFC2475] 167 defined, the traffic conditioner may contain four elements: meter, 168 marker, shaper and dropper. Traffic conditioning performs metering, 169 shaping, policing and/or re-marking to ensure the traffic which 170 entering the DiffServ domain conforms to the service provisioning 171 policy. 173 In DetNet, the traffic policing and conditioning SHOULD include 174 meter, marker, shaper, dropper, scheduler and order. A meter with a 175 DetNet Profile is used to measure the DetNet flows selected by a 176 DetNet classifier and the result of the meter with respect to a 177 packet may be used to trigger a DetNet action including a marking, 178 shaping, dropping, scheduling or ordering. A marker is used to set 179 the Cos field of a DetNet packet to a DetNet DSCP (section 2.3), 180 mapping the marked packet to a DetNet PHB. A Shaper may apply 181 specific shaping algorithms implemented by DetNet network, e.g., 182 credit-based shaper [IEEE802.1Qav]. A dropper is used to discard 183 some of the non-DetNet packets to provide the QoS of the DetNet flows 184 when congestion occurs. 186 2.2.1. Scheduler 188 As decribed in [RFC8655], the DetNet flows can be scheduled to 189 achieve time-based synchronization for scheduled traffic. This 190 document proposes a new type of action for DetNet traffic 191 conditioning named Scheduler action. A scheduler may apply specific 192 scheduling and related Queuing algorithms implemented by DetNet 193 network, e.g., Time-gated queues [IEEE802.1Qbv] and Cyclic Queuing 194 and Forwarding [IEEE802.1Qch]. 196 2.2.2. Order 198 As defined in [I-D.ietf-detnet-mpls], DetNet control word (d-CW) 199 containing sequencing information for packet replication and 200 duplicate elimination purposes. Sequence Number is different packet- 201 by-packet. Based on Detnet MPLS date plane encapsulation, this 202 document proposes a new type of action for DetNet traffic 203 conditioning named order action which used to reorder the packets 204 within a DetNet flow that are received out of order. 206 2.3. DetNet DSCP 208 The DetNet DSCP carried in CoS field in IP header and TC field in 209 MPLS header may be uesd to mark packets at ingress nodes and select a 210 DetNet PHB (section 2.4) at transit nodes. DetNet DSCP MUST be 211 defined to one or more particular values, which MUST be unique for 212 codepoints in the standard space. 214 [Ed.note: We need to define one or more DetNet DSCP values and 215 related DetNet PHB for DetNet-specific treatment.] 217 2.4. DetNet PHB 219 As specified in [RFC2475], per-hop behaviors are defined to permit a 220 reasonably granular means of allocating buffer and bandwidth 221 resources at each node among competing traffic streams. PHB groups 222 will usually share a common constraint such as a packet scheduling or 223 buffer management policy. According to [RFC4594], Default Forwarding 224 (DF) PHB, Assured Forwarding (AF) PHBs, Expedited Forwarding (EF) PHB 225 and Class Selector (CS) PHBs have been defined to provide forwarding 226 treatment. These PHBs can be used to forward DetNet flows based on 227 the requirement. 229 This document defines a new type of Deterministic Networking (DN) PHB 230 which is intended for traffic requiring extremely low data loss rates 231 and bounded latency for DetNet. The DN PHB may include a set of PHB 232 classes, e.g., DN1,DN2,etc. And the number of the class is the same 233 with the DetNet DSCP values. The DSCP in IP header and TC in MPLS 234 header should be mapped to DN PHB with the relevant PHB specification 235 which may be completed in future discussion. 237 2.5. DetNet Queuing 239 As discussed in [RFC8655],the nodes in DetNet network shall queue 240 each received packets to one of the potential transmission ports and 241 provide storage for queued packets, awaiting to submit these for 242 transmission. A port provides one or more queues corresponding to 243 the number of traffic classes. The queuing mechanism should be 244 configured and implemented to DetNet nodes. 246 As defined in [RFC4594], Priority Queuing (PQ) was defined to queue 247 the packets in priority sequence and Rate Queuing (RQ)selects packets 248 according to the specified rate including Weighted Fair Queuing (WFQ) 249 and Weighted Round Robin (WRR). Active Queue Management (AQM) also 250 be defined to use packet dropping or marking to manage the depth of a 251 queue. 253 As per IEEE 802.1 WG, queuing and transmission selection algorithms 254 also can be used for queue scheduling in DetNet network. 256 3. DetNet IP DiffServ Consideration 258 As specified in [I-D.ietf-detnet-ip], no DetNet specific 259 encapsulation is defined to support DetNet IP flow identification and 260 DetNet service delivery. So the DetNet IP classification is the same 261 as defined in [RFC2474] and [RFC2475]. But the recommended DetNet 262 DSCP may be uesd to mark packets to select a DetNet PHB and the 263 transit nodes should implement mechanisms performing the PHB. The 264 mapping of DSCP to PHBs MUST be configurable. Implementations should 265 support the recommended codepoint-to-PHB mappings in their default 266 configuration. 268 4. DetNet MPLS DiffServ Consideration 270 As defined in [I-D.ietf-detnet-mpls], DetNet S-Label and F-Labels can 271 be used in combination with MPLS TC filed in MF classifier. The BA 272 classifier is the same with the [RFC3270]. 274 Two types of LSPs including Explicitly TC-encoded-PSC LSP (E-LSP) and 275 Label-Only-Inferred-PSC LSP (L-LSP) follows the definition of 276 [RFC3270] and can be used to support DetNet explicit routes in MPLS- 277 TE LSP. A E-LSP can be used to support one or more DetNet flows and 278 a L-LSP can be established for one flow. E-LSP and L-LSP can use a 279 signaled TC->PHB mapping to forward packets whose corresponding PHBs 280 are defined in this document. 282 In DetNet MPLS network, DetNet Layer Two Service is supported in TSN 283 over MPLS. The LSP egressing over egde nodes can use the 284 preconfigured PHB->802.1 mapping as defined in [RFC3270]. 286 As specified in [RFC3270], there may be more than one LSP carrying 287 the same flow. Two or more LSPs can be merged into one LSP at one 288 egressing LSR. It can be used to perform the packet replication 289 (PRF) at ingress nodes and the packet elimination (PEF) at the egress 290 nodes in DetNet DiffServ model. The order action which defined in 291 this document can be used for packet ordering functionality (POF). 293 5. Security Considerations 295 TBD. 297 6. IANA Considerations 299 TBD. 301 7. Acknowledgements 303 TBD. 305 8. References 307 8.1. Informative References 309 [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z., 310 and W. Weiss, "An Architecture for Differentiated 311 Services", RFC 2475, DOI 10.17487/RFC2475, December 1998, 312 . 314 8.2. Normative References 316 [I-D.ietf-detnet-ip] 317 Varga, B., Farkas, J., Berger, L., Fedyk, D., Malis, A., 318 Bryant, S., and J. Korhonen, "DetNet Data Plane: IP", 319 draft-ietf-detnet-ip-03 (work in progress), October 2019. 321 [I-D.ietf-detnet-mpls] 322 Varga, B., Farkas, J., Berger, L., Fedyk, D., Malis, A., 323 Bryant, S., and J. Korhonen, "DetNet Data Plane: MPLS", 324 draft-ietf-detnet-mpls-03 (work in progress), October 325 2019. 327 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 328 Requirement Levels", BCP 14, RFC 2119, 329 DOI 10.17487/RFC2119, March 1997, 330 . 332 [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, 333 "Definition of the Differentiated Services Field (DS 334 Field) in the IPv4 and IPv6 Headers", RFC 2474, 335 DOI 10.17487/RFC2474, December 1998, 336 . 338 [RFC3270] Le Faucheur, F., Wu, L., Davie, B., Davari, S., Vaananen, 339 P., Krishnan, R., Cheval, P., and J. Heinanen, "Multi- 340 Protocol Label Switching (MPLS) Support of Differentiated 341 Services", RFC 3270, DOI 10.17487/RFC3270, May 2002, 342 . 344 [RFC4594] Babiarz, J., Chan, K., and F. Baker, "Configuration 345 Guidelines for DiffServ Service Classes", RFC 4594, 346 DOI 10.17487/RFC4594, August 2006, 347 . 349 [RFC5462] Andersson, L. and R. Asati, "Multiprotocol Label Switching 350 (MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic 351 Class" Field", RFC 5462, DOI 10.17487/RFC5462, February 352 2009, . 354 [RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas, 355 "Deterministic Networking Architecture", RFC 8655, 356 DOI 10.17487/RFC8655, October 2019, 357 . 359 Authors' Addresses 361 Quan Xiong 362 ZTE Corporation 363 No.6 Huashi Park Rd 364 Wuhan, Hubei 430223 365 China 367 Phone: +86 27 83531060 368 Email: xiong.quan@zte.com.cn 369 Jinghai Yu 370 ZTE Corporation 371 50 Software Avenue, YuHuaTai District 372 Nanjing, Jiangsu 210012 373 China 375 Phone: +86 025 26774049 376 Email: yu.jinghai@zte.com.cn 378 Peng Liu 379 China Mobile 380 Beijing 100053 381 China 383 Email: liupengyjy@chinamobile.com 385 Fengwei Qin 386 China Mobile 387 Beijing 388 China 390 Email: qinfengwei@chinamobile.com