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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 DetNet B. Varga, Ed. 3 Internet-Draft J. Farkas 4 Intended status: Standards Track Ericsson 5 Expires: August 6, 2020 L. Berger 6 D. Fedyk 7 LabN Consulting, L.L.C. 8 A. Malis 9 Independent 10 S. Bryant 11 Futurewei Technologies 12 J. Korhonen 13 February 3, 2020 15 DetNet Data Plane: MPLS 16 draft-ietf-detnet-mpls-05 18 Abstract 20 This document specifies the Deterministic Networking data plane when 21 operating over an MPLS Packet Switched Networks. 23 Status of This Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at https://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on August 6, 2020. 40 Copyright Notice 42 Copyright (c) 2020 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (https://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 58 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 59 2.1. Terms Used in This Document . . . . . . . . . . . . . . . 3 60 2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4 61 2.3. Requirements Language . . . . . . . . . . . . . . . . . . 5 62 3. DetNet MPLS Data Plane Overview . . . . . . . . . . . . . . . 5 63 3.1. Layers of DetNet Data Plane . . . . . . . . . . . . . . . 5 64 3.2. DetNet MPLS Data Plane Scenarios . . . . . . . . . . . . 6 65 4. MPLS-Based DetNet Data Plane Solution . . . . . . . . . . . . 8 66 4.1. DetNet Over MPLS Encapsulation Components . . . . . . . . 8 67 4.2. MPLS Data Plane Encapsulation . . . . . . . . . . . . . . 9 68 4.2.1. DetNet Control Word and the DetNet Sequence Number . 10 69 4.2.2. S-Labels . . . . . . . . . . . . . . . . . . . . . . 11 70 4.2.3. F-Labels . . . . . . . . . . . . . . . . . . . . . . 14 71 4.3. OAM Indication . . . . . . . . . . . . . . . . . . . . . 16 72 4.4. Flow Aggregation . . . . . . . . . . . . . . . . . . . . 17 73 4.4.1. Aggregation Via LSP Hierarchy . . . . . . . . . . . . 17 74 4.4.2. Aggregating DetNet Flows as a new DetNet flow . . . . 18 75 4.5. Service Sub-Layer Considerations . . . . . . . . . . . . 19 76 4.5.1. Edge Node Processing . . . . . . . . . . . . . . . . 19 77 4.5.2. Relay Node Processing . . . . . . . . . . . . . . . . 20 78 4.6. Forwarding Sub-Layer Considerations . . . . . . . . . . . 20 79 4.6.1. Class of Service . . . . . . . . . . . . . . . . . . 20 80 4.6.2. Quality of Service . . . . . . . . . . . . . . . . . 20 81 5. Management and Control Information Summary . . . . . . . . . 21 82 5.1. Service Sub-Layer Information Summary . . . . . . . . . . 22 83 5.1.1. Service Aggregation Information Summary . . . . . . . 23 84 5.2. Forwarding Sub-Layer Information Summary . . . . . . . . 23 85 6. Security Considerations . . . . . . . . . . . . . . . . . . . 24 86 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 87 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 25 88 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 25 89 9.1. Normative References . . . . . . . . . . . . . . . . . . 25 90 9.2. Informative References . . . . . . . . . . . . . . . . . 27 91 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29 93 1. Introduction 95 Deterministic Networking (DetNet) is a service that can be offered by 96 a network to DetNet flows. DetNet provides these flows extremely low 97 packet loss rates and assured maximum end-to-end delivery latency. 98 General background and concepts of DetNet can be found in [RFC8655]. 100 The DetNet Architecture models the DetNet related data plane 101 functions decomposed into two sub-layers: a service sub-layer and a 102 forwarding sub-layer. The service sub-layer is used to provide 103 DetNet service functions such as protection and reordering. The 104 forwarding sub-layer is used to provide forwarding assurance (low 105 loss, assured latency, and limited reordering). 107 This document specifies the DetNet data plane operation and the on- 108 wire encapsulation of DetNet flows over an MPLS-based Packet Switched 109 Network (PSN) using the service sub-layer reference model. MPLS 110 encapsulation already provides a solid foundation of building blocks 111 to enable the DetNet service and forwarding sub-layer functions. 112 MPLS encapsulated DetNet can be carried over a variety of different 113 network technologies that can provide the DetNet required level of 114 service. However, the specific details of how DetNet MPLS is carried 115 over different network technologies is out of scope of this document. 117 MPLS encapsulated DetNet flows can carry different types of traffic. 118 The details of the types of traffic that are carried in DetNet are 119 also out of scope of this document. An example of IP using DetNet 120 MPLS sub-networks can be found in [I-D.ietf-detnet-ip]. DetNet MPLS 121 may use an associated controller and Operations, Administration, and 122 Maintenance (OAM) functions that are defined outside of this 123 document. 125 Background information common to all data planes for DetNet can be 126 found in the DetNet Data Plane Framework 127 [I-D.ietf-detnet-data-plane-framework]. 129 2. Terminology 131 2.1. Terms Used in This Document 133 This document uses the terminology established in the DetNet 134 architecture [RFC8655] and the the DetNet Data Plane Framework 135 [I-D.ietf-detnet-data-plane-framework]. The reader is assumed to be 136 familiar with these documents, any terminology defined therein and 137 basic MPLS related terminologies in [RFC3031]. 139 The following terminology is introduced in this document: 141 F-Label A Detnet "forwarding" label that identifies the LSP 142 used to forward a DetNet flow across an MPLS PSN, e.g., 143 a hop-by-hop label used between label switching routers 144 (LSR). 146 S-Label A DetNet "service" label that is used between DetNet 147 nodes that implement also the DetNet service sub-layer 148 functions. An S-Label is also used to identify a 149 DetNet flow at DetNet service sub-layer. 151 A-Label A special case of an S-Label, whose aggregation 152 properties are known only at the aggregation and 153 deaggregation end-points. 155 d-CW A DetNet Control Word (d-CW) is used for sequencing 156 information of a DetNet flow at the DetNet service sub- 157 layer. 159 2.2. Abbreviations 161 The following abbreviations are used in this document: 163 CoS Class of Service. 165 CW Control Word. 167 DetNet Deterministic Networking. 169 LSR Label Switching Router. 171 MPLS Multiprotocol Label Switching. 173 MPLS-TE Multiprotocol Label Switching - Traffic Engineering. 175 MPLS-TP Multiprotocol Label Switching - Transport Profile. 177 OAM Operations, Administration, and Maintenance. 179 PE Provider Edge. 181 PEF Packet Elimination Function. 183 PRF Packet Replication Function. 185 PREOF Packet Replication, Elimination and Ordering Functions. 187 POF Packet Ordering Function. 189 PSN Packet Switched Network. 191 PW PseudoWire. 193 QoS Quality of Service. 195 S-PE Switching Provider Edge. 197 T-PE Terminating Provider Edge. 199 TSN Time-Sensitive Network. 201 2.3. Requirements Language 203 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 204 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 205 "OPTIONAL" in this document are to be interpreted as described in BCP 206 14 [RFC2119] [RFC8174] when, and only when, they appear in all 207 capitals, as shown here. 209 3. DetNet MPLS Data Plane Overview 211 3.1. Layers of DetNet Data Plane 213 MPLS provides a wide range of capabilities that can be utilised by 214 DetNet. A straight forward approach utilizing MPLS for a DetNet 215 service sub-layer is based on the existing pseudowire (PW) 216 encapsulations and by utilizing existing MPLS Traffic Engineering 217 encapsulations and mechanisms. Background on PWs can be found in 218 [RFC3985] and [RFC3031]. Background on MPLS Traffic Engineering can 219 be found in [RFC3272] and [RFC3209]. 221 DetNet MPLS 222 . 223 Bottom of Stack . 224 (inner label) +------------+ 225 | Service | d-CW, S-Label (A-Label) 226 +------------+ 227 | Forwarding | F-Label(s) 228 +------------+ 229 Top of Stack . 230 (outer label) . 232 Figure 1: DetNet Adaptation to MPLS Data Plane 234 The DetNet MPLS data plane representation is illustrated in Figure 1. 235 The service sub-layer includes a DetNet control word (d-CW) and a 236 identifying service label (S-Label). The DetNet control word (d-CW) 237 conforms to the Generic PW MPLS Control Word (PWMCW) defined in 238 [RFC4385]. An aggregation label (A-Label) is a special case of 239 S-Label used for aggregation. 241 A node operating on a DetNet flow in the Detnet service sub- 242 layer,uses the local context associated with that S-Label, provided 243 by a received F-Label, to determine what local DetNet operation(s) 244 are applied to that packet. An S-Label may be taken from the 245 platform label space [RFC3031], making it unique, enabling DetNet 246 flow identification regardless of which input interface or LSP the 247 packet arrives on. 249 The DetNet forwarding sub-layer is supported by zero or more 250 forwarding labels (F-Labels). MPLS Traffic Engineering 251 encapsulations and mechanisms can be utilized to provide a forwarding 252 sub-layer that is responsible for providing resource allocation and 253 explicit routes. 255 3.2. DetNet MPLS Data Plane Scenarios 257 DetNet MPLS Relay Transit Relay DetNet MPLS 258 End System Node Node Node End System 259 (T-PE) (S-PE) (LSR) (S-PE) (T-PE) 260 +----------+ +----------+ 261 | Appl. |<------------ End to End Service ----------->| Appl. | 262 +----------+ +---------+ +---------+ +----------+ 263 | Service |<--| Service |-- DetNet flow --| Service |-->| Service | 264 +----------+ +---------+ +----------+ +---------+ +----------+ 265 |Forwarding| |Fwd| |Fwd| |Forwarding| |Fwd| |Fwd| |Forwarding| 266 +-------.--+ +-.-+ +-.-+ +----.---.-+ +-.-+ +-.-+ +---.------+ 267 : Link : / ,-----. \ : Link : / ,-----. \ 268 +........+ +-[ Sub ]-+ +......+ +-[ Sub ]-+ 269 [Network] [Network] 270 `-----' `-----' 271 |<- LSP -->| |<-------- LSP -----------| |<--- LSP -->| 273 |<----------------- DetNet MPLS --------------------->| 275 Figure 2: A DetNet MPLS Network 277 Figure 2 illustrates a hypothetical DetNet MPLS-only network composed 278 of DetNet aware MPLS enabled end systems, operating over a DetNet 279 aware MPLS network. In this figure, the relay nodes are PE devices 280 that define the MPLS LSP boundaries and the transit nodes are LSRs. 282 DetNet end system and relay nodes understand the particular needs of 283 DetNet flows and provide both DetNet service and forwarding sub-layer 284 functions. In the case of MPLS, DetNet service-aware nodes add, 285 remove and process d-CWs, S-Labels and F-labels as needed. DetNet 286 MPLS nodes provide functionality analogous to T-PEs when they sit at 287 the edge of an MPLS domain, and S-PEs when they are in the middle of 288 an MPLS domain, see [RFC6073]. 290 In a DetNet MPLS network, transit nodes may be DetNet service aware 291 or may be DetNet unaware MPLS Label Switching Routers (LSRs). In 292 this latter case, such LSRs would be unaware of the special 293 requirements of the DetNet service sub-layer, but would still provide 294 traffic engineering functions and the QoS capabilities needed to 295 ensure that the (TE) LSPs meet the service requirements of the 296 carried DetNet flows. 298 The application of DetNet using MPLS supports a number of control 299 plane/management plane types. These types support certain MPLS data 300 plane deployments. For example RSVP-TE, MPLS-TP, or MPLS Segment 301 Routing (when extended to support resource allocation) are all valid 302 MPLS deployment cases. 304 Figure 3 illustrates how an end-to-end MPLS-based DetNet service is 305 provided in a more detail. In this figure, the customer end systems, 306 CE1 and CE2, are able to send and receive MPLS encapsulated DetNet 307 flows, and R1, R2 and R3 are relay nodes in the middle of a DetNet 308 network. The 'X' in the end systems, and relay nodes represents 309 potential DetNet compound flow packet replication and elimination 310 points. In this example, service protection is supported utilizing 311 at least two DetNet member flows and TE LSPs. For a unidirectional 312 flow, R1 supports PRF and R3 supports PEF and POF. Note that the 313 relay nodes may change the underlying forwarding sub-layer, for 314 example tunneling MPLS over IEEE 802.1 TSN 315 [I-D.ietf-detnet-mpls-over-tsn], or simply over interconnect network 316 links. 318 DetNet DetNet 319 MPLS Service Transit Transit Service MPLS 320 DetNet | |<-Tnl->| |<-Tnl->| | DetNet 321 End | V 1 V V 2 V | End 322 System | +--------+ +--------+ +--------+ | System 323 +---+ | | R1 |=======| R2 |=======| R3 | | +---+ 324 | X...DFa...|._X_....|..DF1..|.__ ___.|..DF3..|...._X_.|.DFa..|.X | 325 |CE1|========| \ | | X | | / |======|CE2| 326 | | | | \_.|..DF2..|._/ \__.|..DF4..|._/ | | | | 327 +---+ | |=======| |=======| | +---+ 328 ^ +--------+ +--------+ +--------+ ^ 329 | Relay Node Relay Node Relay Node | 330 | (S-PE) (S-PE) (S-PE) | 331 | | 332 |<---------------------- DetNet MPLS --------------------->| 333 | | 334 |<--------------- End to End DetNet Service -------------->| 336 -------------------------- Data Flow -------------------------> 338 X = Optional service protection (none, PRF, PREOF, PEF/POF) 339 DFx = DetNet member flow x over a TE LSP 341 Figure 3: MPLS-Based Native DetNet 343 4. MPLS-Based DetNet Data Plane Solution 345 4.1. DetNet Over MPLS Encapsulation Components 347 To carry DetNet over MPLS the following is required: 349 1. A method of identifying the MPLS payload type. 351 2. A method of identifying the DetNet flow group to the processing 352 element. 354 3. A method of distinguishing DetNet OAM packets from DetNet data 355 packets. 357 4. A method of carrying the DetNet sequence number. 359 5. A suitable LSP to deliver the packet to the egress PE. 361 6. A method of carrying queuing and forwarding indication. 363 In this design an MPLS service label (the S-Label), similar to a 364 pseudowire (PW) label [RFC3985], is used to identify both the DetNet 365 flow identity and the payload MPLS payload type satisfying (1) and 366 (2) in the list above. OAM traffic discrimination happens through 367 the use of the Associated Channel method described in [RFC4385]. The 368 DetNet sequence number is carried in the DetNet Control word which 369 carries the Data/OAM discriminator. To simplify implementation and 370 to maximize interoperability two sequence number sizes are supported: 371 a 16 bit sequence number and a 28 bit sequence number. The 16 bit 372 sequence number is needed to support some types of legacy clients. 373 The 28 bit sequence number is used in situations where it is 374 necessary ensure that in high speed networks the sequence number 375 space does not wrap whilst packets are in flight. 377 The LSP used to forward the DetNet packet is not restricted regarding 378 any method used for establishing that LSP (for example, MPLS-LDP, 379 MPLS-TE, MPLS-TP [RFC5921], MPLS-SR [RFC8660], etc.). The LSP 380 (F-Label) label and/or the S-Label may be used to indicate the queue 381 processing as well as the forwarding parameters. Note that the 382 possible use of Penultimate Hop Popping (PHP) means that the S-Label 383 may be the only label received at the terminating DetNet service. 385 4.2. MPLS Data Plane Encapsulation 387 Figure 4 illustrates a DetNet data plane MPLS encapsulation. The 388 MPLS-based encapsulation of the DetNet flows is well suited for the 389 scenarios described in [I-D.ietf-detnet-data-plane-framework]. 390 Furthermore, an end to end DetNet service i.e., native DetNet 391 deployment (see Section 3.2) is also possible if DetNet end systems 392 are capable of initiating and termination MPLS encapsulated packets. 394 The MPLS-based DetNet data plane encapsulation consists of: 396 o DetNet control word (d-CW) containing sequencing information for 397 packet replication and duplicate elimination purposes, and the OAM 398 indicator. 400 o DetNet service Label (S-Label) that identifies a DetNet flow at 401 the receiving DetNet service sub-layer processing node. 403 o Zero or more Detnet MPLS Forwarding label(s) (F-Label) used to 404 direct the packet along the label switched path (LSP) to the next 405 service sub-layer processing node along the path. When 406 Penultimate Hop Popping is in use there may be no label F-Label in 407 the protocol stack on the final hop. 409 o The necessary data-link encapsulation is then applied prior to 410 transmission over the physical media. 412 DetNet MPLS-based encapsulation 414 +---------------------------------+ 415 | | 416 | DetNet App-Flow | 417 | Payload Packet | 418 | | 419 +---------------------------------+ <--\ 420 | DetNet Control Word | | 421 +---------------------------------+ +--> DetNet data plane 422 | S-Label | | MPLS encapsulation 423 +---------------------------------+ | 424 | [ F-Label(s) ] | | 425 +---------------------------------+ <--/ 426 | Data-Link | 427 +---------------------------------+ 428 | Physical | 429 +---------------------------------+ 431 Figure 4: Encapsulation of a DetNet App-Flow in an MPLS PSN 433 4.2.1. DetNet Control Word and the DetNet Sequence Number 435 A DetNet control word (d-CW) conforms to the Generic PW MPLS Control 436 Word (PWMCW) defined in [RFC4385]. The d-CW formatted as shown in 437 Figure 5 MUST be present in all DetNet packets containing app-flow 438 data. This format of the d-CW was created in order (1) to allow 439 larger S/N space to avoid S/N rollover frequency in some applications 440 and (2) to allow non-skip zero S/N what simplifies implementation. 442 0 1 2 3 443 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 1 444 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 445 |0 0 0 0| Sequence Number | 446 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 448 Figure 5: DetNet Control Word 450 (bits 0 to 3) 452 Per [RFC4385], MUST be set to zero (0). 454 Sequence Number (bits 4 to 31) 456 An unsigned value implementing the DetNet sequence number. 458 A separate sequence number space MUST be maintained by the node that 459 adds the d-CW for each DetNet app-flow. The following sequence 460 number field lengths MUST be supported: 462 0 bits 464 16 bits 466 28 bits 468 The sequence number length MUST be provisioned on a per app-flow 469 basis via configuration, i.e., via the controller plane described in 470 [I-D.ietf-detnet-data-plane-framework]. 472 A 0 bit sequence number field length indicates that there is no 473 DetNet sequence number used for the flow. When the length is zero, 474 the sequence number field MUST be set to zero (0) on all packets sent 475 for the flow. 477 When the sequence number field length is 16 or 28 bits for a flow, 478 the sequence number MUST be incremented by one for each new app-flow 479 packet sent. When the field length is 16 bits, d-CW bits 4 to 15 480 MUST be set to zero (0). The values carried in this field can wrap 481 and it is important to note that zero (0) is a valid field value. 482 For example, were the sequence number size is 16 bits, the sequence 483 will contain: 65535, 0, 1, where zero (0) is an ordinary sequence 484 number. 486 It is important to note that this document differs from [RFC4448] 487 where a sequence number of zero (0) is used to indicate that the 488 sequence number check algorithm is not used. 490 The sequence number is optionally used during receive processing as 491 described below in Section 4.2.2.1 and Section 4.2.2.2. 493 4.2.2. S-Labels 495 App-flow identification at a DetNet service sub-layer is realized by 496 an S-Label. MPLS-aware DetNet end systems and edge nodes, which are 497 by definition MPLS ingress and egress nodes, MUST add and remove an 498 app-flow specific d-CW and S-Label. Relay nodes MAY swap S-Label 499 values when processing an app-flow. 501 The S-Label value MUST be provisioned per app-flow via configuration, 502 e.g., via the controller plane described in 503 [I-D.ietf-detnet-data-plane-framework]. Note that S-Labels provide 504 app-flow identification at the downstream DetNet service sub-layer 505 receiver, not the sender. As such, S-Labels MUST be allocated by the 506 entity that controls the service sub-layer receiving node's label 507 space, and MAY be allocated from the platform label space [RFC3031]. 508 Because S-Labels are local to each node rather than being a global 509 identifier within a domain, they must be advertised to their upstream 510 DetNet service-aware peer nodes (e.g., a DetNet MPLS End System or a 511 DetNet Relay or Edge Node and interpreted in the context of their 512 received F-Label. 514 The S-Label will normally be at the bottom of the label stack once 515 the last F-Label is removed, immediately preceding the d-CW. To 516 support service sub-layer level OAM, an OAM Associated Channel Header 517 (ACH) [RFC4385] together with a Generic Associated Channel Label 518 (GAL) [RFC5586] MAY be used in place of a d-CW. 520 Similarly, an Entropy Label Indicator/Entropy Label (ELI/EL) 521 [RFC6790] MAY be carried below the S-Label in the label stack in 522 networks where DetNet flows would otherwise received ECMP treatment. 523 When ELs are used, the same EL value SHOULD be used for all of the 524 packets sent using a specific S-Label to force the flow to follow the 525 same path. However, as outlines in 526 [I-D.ietf-detnet-data-plane-framework] the use of ECMP for DetNet 527 flows is NOT RECOMMENDED. ECMP MAY be used for non-DetNet flows 528 within a DetNet domain. 530 When receiving a DetNet MPLS flow, an implementation MUST identify 531 the app-flow associated with the incoming packet based on the 532 S-Label. When a node is using platform labels for S-Labels, no 533 additional information is needed as the S-label uniquely identifies 534 the app-flow. In the case where platform labels are not used, zero 535 or more F-Labels and optionally, the incoming interface, proceeding 536 the S-Label MUST be used together with the S-Label to uniquely 537 identify the app-flows associated with a received packet. The 538 incoming interface MAY also be used to together with any present 539 F-Label(s) and the S-Label to uniquely identify an incoming app- 540 flows, for example, to in the case where PHP is used. Note that 541 choice to use platform label space for S-Label or S-Label plus one or 542 more F-Labels to identify app flows is a local implementation choice, 543 with one caveat. When one or more F-labels, or incoming interface, 544 is needed together with an S-Label to uniquely identify, the 545 controller plane MUST ensure that incoming DetNet MPLS packets arrive 546 with the needed information (F-label(s) and/or incoming interface); 547 the details of such are outside the scope of this document. 549 The use of platform labels for S-Labels matches other pseudowire 550 encapsulations for consistency but there is no hard requirement in 551 this regard. 553 4.2.2.1. Packet Elimination Function Processing 555 Implementations MAY support the Packet Elimination Function (PEF) for 556 received DetNet MPLS flows. When supported, use of the PEF for a 557 particular app-flow MUST be provisioned via configuration, e.g., via 558 the controller plane described in 559 [I-D.ietf-detnet-data-plane-framework]. 561 After an app-flow is identified for a received DetNet MPLS packet, as 562 described above, an implementation MUST check if PEF is configured 563 for that app-flow. When configured, the implementation MUST track 564 the sequence number contained in received d-CWs and MUST ensure that 565 duplicate (replicated) instances of a particular sequence number are 566 discarded. The specific mechanisms used for an implementation to 567 identify which received packets are duplicates and which are new is 568 an implementation choice. Note that per Section 4.2.1 the sequence 569 number field length may be 16 or 28 bits, and the field value can 570 wrap. 572 Note that an implementation MAY wish to constrain the maximum number 573 sequence numbers that are tracked, on platform-wide or per flow 574 basis. Some implementations MAY support the provisioning of the 575 maximum number sequence numbers that are tracked number on either a 576 platform-wide or per flow basis. 578 4.2.2.2. Packet Ordering Function Processing 580 A function that is related to in-order delivery is the Packet 581 Ordering Function (POF). Implementations MAY support POF. When 582 supported, use of the POF for a particular app-flow MUST be 583 provisioned via configuration, e.g., via the controller plane 584 described by [I-D.ietf-detnet-data-plane-framework]. Implementations 585 MAY required that PEF and POF be used in combination. There is no 586 requirement related to the order of execution of the Packet 587 Elimination and Ordering Functions in an implementation. 589 After an app-flow is identified for a received DetNet MPLS packet, as 590 described above, an implementation MUST check if POF is configured 591 for that app-flow. When configured, the implementation MUST track 592 the sequence number contained in received d-CWs and MUST ensure that 593 packets are processed in the order indicated in the received d-CW 594 sequence number field, which may not be in the order the packets are 595 received. As defined in Section 4.2.1 the sequence number field 596 length may be 16 or 28 bits, is incremented by one (1) for each new 597 app-flow packet sent, and the field value can wrap. The specific 598 mechanisms used for an implementation to identify the order of 599 received packets is an implementation choice. 601 Note that an implementation MAY wish to constrain the maximum number 602 of out of order packets that can be processed, on platform-wide or 603 per flow basis. Some implementations MAY support the provisioning of 604 this number on either a platform-wide or per flow basis. The number 605 of out of order packets that can be processed also impacts the 606 latency of a flow. 608 4.2.3. F-Labels 610 F-Labels are supported the DetNet forwarding sub-layer. F-Labels are 611 used to provide LSP-based connectivity between DetNet service sub- 612 layer processing nodes. 614 4.2.3.1. Service Sub-Layer and Packet Replication Function Processing 616 DetNet MPLS end systems, edge nodes and relay nodes may operate at 617 the DetNet service sub-layer with understand of app-flows and their 618 requirements. As mentioned earlier, when operating at this layer 619 such nodes can push, pop or swap (pop then push) S-Labels. In all 620 cases, the F-Labels used for the app-flow are always replaced and the 621 following procedures apply. 623 When sending a DetNet flow, zero or more F-Labels MAY be pushed on 624 top of an S-Label by the node pushing an S-Label. The F-Labels to be 625 pushed when sending a particular app-flow MUST be provisioned per 626 app-flow via configuration, e.g., via the controller plane discussed 627 in [I-D.ietf-detnet-data-plane-framework]. F-Labels can also provide 628 context for an S-Label. To allow for the omission of F-Labels, an 629 implementation SHOULD also allow an outgoing interface to be used. 631 The Packet Replication Function (PRF) function MAY be supported by an 632 implementation for outgoing DetNet flows. When replication is 633 supported, the same app-flow data will be sent over multiple outgoing 634 forwarding sub-layer LSPs. To support PRF an implementation MUST 635 support the setting of different sets of F-Labels. To allow for the 636 omission of F-Labels, an implementation SHOULD also allow multiple 637 outgoing interfaces to be provisioned. PRF MUST NOT be used with 638 app-flows configured with a d-CW sequence number field length of 0 639 bits. 641 When a single set of F-Labels is provisioned for a particular 642 outgoing app-flow, that set of F-labels MUST be pushed after the 643 S-Label is pushed. The outgoing packet is then forwarded as 644 described below in Section 4.2.3.2. When a single outgoing interface 645 is provisioned, the outgoing packet is then forwarded as described 646 below in Section 4.2.3.2. 648 When multiple sets of F-Labels or interfaces are provisioned for a 649 particular outgoing app-flow, a copy of the outgoing packet, 650 including the pushed S-Label, MUST be made per F-label set and 651 outgoing interface. Each set of provisioned F-Labels are then pushed 652 onto a copy of the packet. Each copy is then forwarded as described 653 below in Section 4.2.3.2. 655 As described in the previous section, when receiving a DetNet MPLS 656 flow, an implementation identifies the app-flow associated with the 657 incoming packet based on the S-Label. When a node is using platform 658 labels for S-Labels, any F-Labels can be popped and the S-label 659 uniquely identifies the app-flow. In the case where platform labels 660 are not used, F-Label(s) and, optionally, the incoming interface MUST 661 also be provisioned for incoming app-flows. The provisioned 662 information MUST then be used to identify incoming app-flows based on 663 the combination of S-Label and F-Label(s) or incoming interface. 665 4.2.3.2. Common F-Label Processing 667 All DetNet aware MPLS nodes process F-Labels as needed to meet the 668 service requirements of the DetNet flow or flows carried in the LSPs 669 represented by the F-Labels. This includes normal push, pop and swap 670 operations. Such processing is essentially the same type of 671 processing provided for TE LSPs, although the specific service 672 parameters, or traffic specification, can differ. When the DetNet 673 service parameters of the app-flow or flows carried in an LSP 674 represented by an F-Label can be met by an exiting TE mechanism, the 675 forwarding sub-layer processing node MAY be a DetNet unaware, i.e., 676 standard, MPLS LSR. Such TE LSPs may provide LSP forwarding service 677 as defined in, but not limited to, [RFC3209], [RFC3270], [RFC3272], 678 [RFC3473], [RFC4875], [RFC5440], and [RFC8306]. 680 More specifically, as mentioned above, the DetNet forwarding sub- 681 layer provides explicit routes and allocated resources, and F-Labels 682 are used to map to each. Explicit routes are supported based on the 683 topmost (outermost) F-Label that is pushed or swapped and the LSP 684 that corresponds to this label. This topmost (outgoing) label MUST 685 be associated with a provisioned outgoing interface and, for non- 686 point-to-point outgoing interfaces, a next hop LSR. Note that this 687 information MUST be provisioned via configuration or the controller 688 plane. In the previously mentioned special case where there are no 689 added F-labels and the outgoing interface is not a point-to-point 690 interface, the outgoing interface MUST also be associated with a next 691 hop LSR. 693 Resources may be allocated in a hierarchical fashion per LSP that is 694 represented by each F-Label. Each LSP MAY be provisioned with a 695 service parameters that dictates the specific traffic treatment to be 696 received by the traffic carried over that LSP. Implementations of 697 this document MUST ensure that traffic carried over each LSP 698 represented by one or more F-Labels receives the traffic treatment 699 provisioned for that LSP. Typical mechanisms used to provide 700 different treatment to different flows includes the allocation of 701 system resources (such as queues and buffers) and provisioning or 702 related parameters (such as shaping, and policing). Support can also 703 be provided via an underlying network technology such IEEE802.1 TSN 704 [I-D.ietf-detnet-mpls-over-tsn]. The specific mechanisms used by a 705 DetNet node to ensure DetNet service delivery requirements are met 706 for supported DetNet flows is outside the scope of this document. 708 Packets that are marked in a way that do not correspond to allocated 709 resources, e.g., lack a provisioned F-Label, can disrupt the QoS 710 offered to properly reserved DetNet flows by using resources 711 allocated to the reserved flows. Therefore, the network nodes of a 712 DetNet network: 714 o MUST defend the DetNet QoS by discarding or remarking (to an 715 allocated DetNet flow or non-competing non-DetNet flow) packets 716 received that are not associated with a completed resource 717 allocation. 719 o MUST NOT use a DetNet allocated resource, e.g. a queue or shaper 720 reserved for DetNet flows, for any packet that does match the 721 corresponding DetNet flow. 723 o MUST ensure a QoS flow does not exceed its allocated resources or 724 provisioned service level, 726 o MUST ensure a CoS flow or service class does not impact the 727 service delivered to other flows. This requirement is similar to 728 requirement for MPLS LSRs to that CoS LSPs do not impact the 729 resources allocated to TE LSPs, e.g., via [RFC3473]. 731 Subsequent sections provide additional considerations related to CoS 732 (Section 4.6.1), QoS (Section 4.6.2) and aggregation (Section 4.4). 734 4.3. OAM Indication 736 OAM follows the procedures set out in [RFC5085] with the restriction 737 that only Virtual Circuit Connectivity Verification (VCCV) type 1 is 738 supported. 740 As shown in Figure 3 of [RFC5085] when the first nibble of the d-CW 741 is 0x0 the payload following the d-CW is normal user data. However, 742 when the first nibble of the d-CW is 0X1, the payload that follows 743 the d-DW is an OAM payload with the OAM type indicated by the value 744 in the d-CW Channel Type field. 746 The reader is referred to [RFC5085] for a more detailed description 747 of the Associated Channel mechanism, and to the DetNet work on OAM 748 for more information DetNet OAM. 750 Additional considerations on DetNet-specific OAM are subjects for 751 further study. 753 4.4. Flow Aggregation 755 The ability to aggregate individual flows, and their associated 756 resource control, into a larger aggregate is an important technique 757 for improving scaling of control in the data, management and control 758 planes. The DetNet data plane allows for the aggregation of DetNet 759 flows, to improved scaling. There are two methods of supporting flow 760 aggregation covered in this section. 762 The resource control and management aspects of aggregation (including 763 the configuration of queuing, shaping, and policing) are the 764 responsibility of the DetNet controller plane and is out of scope of 765 this documents. It is also the responsibility of the controller 766 plane to ensure that consistent aggregation methods are used. 768 4.4.1. Aggregation Via LSP Hierarchy 770 DetNet flows forwarded via MPLS can leverage MPLS-TE's existing 771 support for hierarchical LSPs (H-LSPs), see [RFC4206]. H-LSPs are 772 typically used to aggregate control and resources, they may also be 773 used to provide OAM or protection for the aggregated LSPs. Arbitrary 774 levels of aggregation naturally falls out of the definition for 775 hierarchy and the MPLS label stack [RFC3032]. DetNet nodes which 776 support aggregation (LSP hierarchy) map one or more LSPs (labels) 777 into and from an H-LSP. Both carried LSPs and H-LSPs may or may not 778 use the TC field, i.e., L-LSPs or E-LSPs. Such nodes will need to 779 ensure that individual LSPs and H-LSPs receive the traffic treatment 780 required to ensure the required DetNet service is preserved. 782 Additional details of the traffic control capabilities needed at a 783 DetNet-aware node may be covered in the new service definitions 784 mentioned above or in separate future documents. Controller plane 785 mechanisms will also need to ensure that the service required on the 786 aggregate flow are provided, which may include the discarding or 787 remarking mentioned in the previous sections. 789 4.4.2. Aggregating DetNet Flows as a new DetNet flow 791 An aggregate can be built by layering DetNet flows, including both 792 their S-Label and, when present, F-Labels as shown below: 794 +---------------------------------+ 795 | | 796 | DetNet Flow | 797 | Payload Packet | 798 | | 799 +---------------------------------+ <--\ 800 | DetNet Control Word | | 801 +=================================+ | 802 | S-Label | | 803 +---------------------------------+ | 804 | [ F-Label(s) ] | +----DetNet data plane 805 +---------------------------------+ | 806 | DetNet Control Word | | 807 +=================================+ | 808 | A-Label | | 809 +---------------------------------+ | 810 | F-Label(s) | <--/ 811 +---------------------------------+ 812 | Data-Link | 813 +---------------------------------+ 814 | Physical | 815 +---------------------------------+ 817 Figure 6: DetNet Aggregation as a new DetNet Flow 819 Both the aggregation label, which is referred to as an A-Label, and 820 the individual flow's S-Label have their MPLS S bit set indicating 821 bottom of stack, and the d-CW allows the PREOF to work. An A-Label 822 is a special case of an S-Label, whose properties are known only at 823 the aggregation and deaggregation end-points. 825 It is a property of the A-Label that what follows is a d-CW followed 826 by an MPLS label stack. A relay node processing the A-Label would 827 not know the underlying payload type, and the A-Label would be 828 process as a normal S-Label. This would only be known to a node that 829 was a peer of the node imposing the S-Label. However there is no 830 real need for it to know the payload type during aggregation 831 processing. 833 As in the previous section, nodes supporting this type of aggregation 834 will need to ensure that individual and aggregated flows receive the 835 traffic treatment required to ensure the required DetNet service is 836 preserved. Also, it is the controller plane's responsibility to to 837 ensure that the service required on the aggregate flow are properly 838 provisioned. 840 4.5. Service Sub-Layer Considerations 842 The edge and relay node internal procedures related to PREOF are 843 implementation specific. The order of a packet elimination or 844 replication is out of scope in this specification. 846 It is important that the DetNet layer is configured such that a 847 DetNet node never receives its own replicated packets. If it were to 848 receive such packets the replication function would make the loop 849 more destructive of bandwidth than a conventional unicast loop. 850 Ultimately the TTL in the S-Label will cause the packet to die during 851 a transient loop, but given the sensitivity of applications to packet 852 latency the impact on the DetNet application would be severe. To 853 avoid the problem of a transient forwarding loop, changes to an LSP 854 supporting DetNet MUST be loop-free. 856 4.5.1. Edge Node Processing 858 An edge node is responsible for matching ingress packets to the 859 service they require and encapsulating them accordingly. An edge 860 node may participate in the packet replication and duplicate packet 861 elimination. 863 The DetNet-aware forwarder selects the egress DetNet member flow 864 segment based on the flow identification. The mapping of ingress 865 DetNet member flow segment to egress DetNet member flow segment may 866 be statically or dynamically configured. Additionally the DetNet- 867 aware forwarder does duplicate frame elimination based on the flow 868 identification and the sequence number combination. The packet 869 replication is also done within the DetNet-aware forwarder. During 870 elimination and the replication process the sequence number of the 871 DetNet member flow MUST be preserved and copied to the egress DetNet 872 member flow. 874 The internal design of a relay node is out of scope of this document. 875 However the reader's attention is drawn to the need to make any PREOF 876 state available to the packet processor(s) dealing with packets to 877 which the PREOF functions must be applied, and to maintain that state 878 is such as way that it is available to the packet processor operation 879 on the next packet in the DetNet flow (which may be a duplicate, a 880 late packet, or the next packet in sequence. 882 4.5.2. Relay Node Processing 884 A DetNet Relay node operates in the DetNet forwarding sub-layer . 885 For DetNet using MPLS this processing is performed on the F-Label. 886 This processing is done within an extended forwarder function. 887 Whether an ingress DetNet member flow receives DetNet specific 888 processing depends on how the forwarding is programmed. Some relay 889 nodes may be DetNet service aware, while others may be unmodified 890 LSRs that only understand how to switch MPLS-TE LSPs. 892 It is also possible to treat the relay node as a transit node, see 893 Section 4.4. Again, this is entirely up to how the forwarding has 894 been programmed. 896 4.6. Forwarding Sub-Layer Considerations 898 4.6.1. Class of Service 900 Class and quality of service, i.e., CoS and QoS, are terms that are 901 often used interchangeably and confused with each other. In the 902 context of DetNet, CoS is used to refer to mechanisms that provide 903 traffic forwarding treatment based on aggregate group basis and QoS 904 is used to refer to mechanisms that provide traffic forwarding 905 treatment based on a specific DetNet flow basis. Examples of 906 existing network level CoS mechanisms include DiffServ which is 907 enabled by IP header differentiated services code point (DSCP) field 908 [RFC2474] and MPLS label traffic class field [RFC5462], and at Layer- 909 2, by IEEE 802.1p priority code point (PCP). 911 CoS for DetNet flows carried in PWs and MPLS is provided using the 912 existing MPLS Differentiated Services (DiffServ) architecture 913 [RFC3270]. Both E-LSP and L-LSP MPLS DiffServ modes MAY be used to 914 support DetNet flows. The Traffic Class field (formerly the EXP 915 field) of an MPLS label follows the definition of [RFC5462] and 916 [RFC3270]. The Uniform, Pipe, and Short Pipe DiffServ tunneling and 917 TTL processing models are described in [RFC3270] and [RFC3443] and 918 MAY be used for MPLS LSPs supporting DetNet flows. MPLS ECN MAY also 919 be used as defined in ECN [RFC5129] and updated by [RFC5462]. 921 4.6.2. Quality of Service 923 In addition to explicit routes, and packet replication and 924 elimination, described in Section 4 above, DetNet provides zero 925 congestion loss and bounded latency and jitter. As described in 926 [RFC8655], there are different mechanisms that maybe used separately 927 or in combination to deliver a zero congestion loss service. This 928 includes Quality of Service (QoS) mechanisms at the MPLS layer, that 929 may be combined with the mechanisms defined by the underlying network 930 layer such as 802.1TSN. 932 Quality of Service (QoS) mechanisms for flow specific traffic 933 treatment typically includes a guarantee/agreement for the service, 934 and allocation of resources to support the service. Example QoS 935 mechanisms include discrete resource allocation, admission control, 936 flow identification and isolation, and sometimes path control, 937 traffic protection, shaping, policing and remarking. Example 938 protocols that support QoS control include Resource ReSerVation 939 Protocol (RSVP) [RFC2205] (RSVP) and RSVP-TE [RFC3209] and [RFC3473]. 940 The existing MPLS mechanisms defined to support CoS [RFC3270] can 941 also be used to reserve resources for specific traffic classes. 943 A baseline set of QoS capabilities for DetNet flows carried in PWs 944 and MPLS can provided by MPLS with Traffic Engineering (MPLS-TE) 945 [RFC3209] and [RFC3473]. TE LSPs can also support explicit routes 946 (path pinning). Current service definitions for packet TE LSPs can 947 be found in "Specification of the Controlled Load Quality of 948 Service", [RFC2211], "Specification of Guaranteed Quality of 949 Service", [RFC2212], and "Ethernet Traffic Parameters", [RFC6003]. 950 Additional service definitions are expected in future documents to 951 support the full range of DetNet services. In all cases, the 952 existing label-based marking mechanisms defined for TE-LSPs and even 953 E-LSPs are use to support the identification of flows requiring 954 DetNet QoS. 956 5. Management and Control Information Summary 958 The specific information needed for the processing of each DetNet 959 service depends on the DetNet node type and the functions being 960 provided on the node. This section summarizes based on the DetNet 961 sub-layer and if the DetNet traffic is being sent or received. All 962 DetNet node types are DetNet forwarding sub-layer aware, while all 963 but transit nodes are service sub-layer aware. This is shown in 964 Figure 2. 966 Much like other MPLS labels, there are a number of alternatives 967 available for DetNet S-Label and F-Label advertisement to an upstream 968 peer node. These include distributed signaling protocols such as 969 RSVP-TE, centralized label distribution via a controller that manages 970 both the sender and the receiver using NETCONF/YANG, BGP, PCEP, etc., 971 and hybrid combinations of the two. The details of the controller 972 plane solution required for the label distribution and the management 973 of the label number space are out of scope of this document. There 974 are particular DetNet considerations and requirements that are 975 discussed in [I-D.ietf-detnet-data-plane-framework]. 977 5.1. Service Sub-Layer Information Summary 979 The following summarizes the information that is needed on service 980 sub-layer aware nodes that send DetNet MPLS traffic, on a per service 981 basis: 983 o App-Flow identification information, e.g., an incoming service on 984 a relay node or IP information as defined in 985 [I-D.ietf-detnet-ip-over-mpls]. 987 o The sequence number length to be used for the service. Valid 988 values included 0, 16 and 28 bits. 0 bits cannot be used when PRF 989 is configured for the service. 991 o The S-Label for the service. 993 o If PRF is to be provided for the service. 995 o The forwarding sub-layer information associated with the output of 996 the service sub-layer. Note that when the PRF function is 997 provisioned, this information is per DetNet member flow. 998 Logically the forwarding sub-layer information is a pointer to 999 further details of transmission of Detnet flows at the forwarding 1000 sub-layer. 1002 The following summarizes the information that is needed on service 1003 sub-layer aware nodes that receives DetNet MPLS traffic, on a per 1004 service basis: 1006 o The forwarding sub-layer information associated with the input of 1007 the service sub-layer. Note that when the PEF function is 1008 provisioned, this information is per DetNet member flow. 1009 Logically the forwarding sub-layer information is a pointer to 1010 further details of the reception of Detnet flows at the forwarding 1011 sub-layer or A-Label. 1013 o The S-Label for the received service. 1015 o If PEF or POF is to be provided for the service. 1017 o The sequence number length to be used for the service. Valid 1018 values included 0, 16 and 28 bits. 0 bits cannot be used when PEF 1019 or POF are configured for the service. 1021 5.1.1. Service Aggregation Information Summary 1023 Nodes performing aggregation using A-Labels, per 1024 Section Section 4.4.2, require the additional information summarized 1025 in this section. 1027 The following summarizes the information that is needed on a node 1028 that sends aggregated flows using A-Labels: 1030 o The S-Labels or F-Labels that are to be carried over each 1031 aggregated service. 1033 o The A-Label associated with each aggregated service. 1035 o The other S-Label information summarized above. 1037 On the receiving node, the A-Label provides the forwarding context of 1038 an incoming interface or an F-Label and is used in subsequent service 1039 or forwarding sub-layer receive processing, as appropriated. The 1040 related addition configuration that may be provided discussed 1041 elsewhere in this section. 1043 5.2. Forwarding Sub-Layer Information Summary 1045 The following summarizes the information that is needed on forwarding 1046 sub-layer aware nodes that send DetNet MPLS traffic, on a per 1047 forwarding sub-layer flow basis: 1049 o The outgoing F-Label stack to be pushed. The stack may include 1050 H-LSP labels. 1052 o The traffic parameters associated with a specific label in the 1053 stack. Note that there may be multiple sets of traffic paramters 1054 associated with specific labels in the stack, e.g., when H-LSPs 1055 are used. 1057 o Outgoing interface and, for unicast traffic, the next hop 1058 information. 1060 o Sub-network specific parameters on a technology specific basis. 1061 For example, see [I-D.ietf-detnet-mpls-over-tsn]. 1063 The following summarizes the information that is needed on forwarding 1064 sub-layer aware nodes that receive DetNet MPLS traffic, on a per 1065 forwarding sub-layer flow basis: 1067 o The incoming interface. For some implementations and deployment 1068 scenarios, this information may not be needed. 1070 o The incoming F-Label stack to be popped. The stack may include 1071 H-LSP labels. 1073 o How the incoming forwarding sub-layer flow is to be handled, i.e., 1074 forwarded as a transit node, or provided to the service sub-layer. 1076 It is the responsibility of the DetNet controller plane to properly 1077 provision both flow identification information and the flow specific 1078 resources needed to provided the traffic treatment needed to meet 1079 each flow's service requirements. This applies for aggregated and 1080 individual flows. 1082 6. Security Considerations 1084 General security considerations are described in [RFC8655]. 1085 Additionally, security considerations and a threat analysis are 1086 described in [I-D.ietf-detnet-security]. This section considers 1087 exclusively security considerations which are specific to the DetNet 1088 MPLS data plane. 1090 Security aspects which are unique to DetNet are those whose aim is to 1091 provide the specific quality of service aspects of DetNet, which are 1092 primarily to deliver data flows with extremely low packet loss rates 1093 and bounded end-to-end delivery latency. 1095 The primary considerations for the data plane is to maintain 1096 integrity of data and delivery of the associated DetNet service 1097 traversing the DetNet network. Application flows can be protected 1098 through whatever means is provided by the underlying technology. For 1099 example, encryption may be used, such as that provided by IPSec 1100 [RFC4301] for IP flows and/or by an underlying sub-net using MACSec 1101 [IEEE802.1AE-2018] for IP over Ethernet (Layer-2) flows. 1103 From a data plane perspective this document does not add or modify 1104 any header information. 1106 At the management and control level DetNet flows are identified on a 1107 per-flow basis, which may provide controller plane attackers with 1108 additional information about the data flows (when compared to 1109 controller planes that do not include per-flow identification). This 1110 is an inherent property of DetNet which has security implications 1111 that should be considered when determining if DetNet is a suitable 1112 technology for any given use case. 1114 To provide uninterrupted availability of the DetNet service, 1115 provisions can be made against DOS attacks and delay attacks. To 1116 protect against DOS attacks, excess traffic due to malicious or 1117 malfunctioning devices can be prevented or mitigated, for example 1118 through the use of existing mechanism such as policing and shaping 1119 applied at the input of a DetNet domain. To prevent DetNet packets 1120 from being delayed by an entity external to a DetNet domain, DetNet 1121 technology definition can allow for the mitigation of Man-In-The- 1122 Middle attacks, for example through use of authentication and 1123 authorization of devices within the DetNet domain. 1125 7. IANA Considerations 1127 This document makes no IANA requests. 1129 8. Acknowledgements 1131 The authors wish to thank Pat Thaler, Norman Finn, Loa Anderson, 1132 David Black, Rodney Cummings, Ethan Grossman, Tal Mizrahi, David 1133 Mozes, Craig Gunther, George Swallow, Yuanlong Jiang and Carlos J. 1134 Bernardos for their various contributions to this work. 1136 9. References 1138 9.1. Normative References 1140 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1141 Requirement Levels", BCP 14, RFC 2119, 1142 DOI 10.17487/RFC2119, March 1997, 1143 . 1145 [RFC2211] Wroclawski, J., "Specification of the Controlled-Load 1146 Network Element Service", RFC 2211, DOI 10.17487/RFC2211, 1147 September 1997, . 1149 [RFC2212] Shenker, S., Partridge, C., and R. Guerin, "Specification 1150 of Guaranteed Quality of Service", RFC 2212, 1151 DOI 10.17487/RFC2212, September 1997, 1152 . 1154 [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol 1155 Label Switching Architecture", RFC 3031, 1156 DOI 10.17487/RFC3031, January 2001, 1157 . 1159 [RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y., 1160 Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack 1161 Encoding", RFC 3032, DOI 10.17487/RFC3032, January 2001, 1162 . 1164 [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., 1165 and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP 1166 Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, 1167 . 1169 [RFC3270] Le Faucheur, F., Wu, L., Davie, B., Davari, S., Vaananen, 1170 P., Krishnan, R., Cheval, P., and J. Heinanen, "Multi- 1171 Protocol Label Switching (MPLS) Support of Differentiated 1172 Services", RFC 3270, DOI 10.17487/RFC3270, May 2002, 1173 . 1175 [RFC3443] Agarwal, P. and B. Akyol, "Time To Live (TTL) Processing 1176 in Multi-Protocol Label Switching (MPLS) Networks", 1177 RFC 3443, DOI 10.17487/RFC3443, January 2003, 1178 . 1180 [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label 1181 Switching (GMPLS) Signaling Resource ReserVation Protocol- 1182 Traffic Engineering (RSVP-TE) Extensions", RFC 3473, 1183 DOI 10.17487/RFC3473, January 2003, 1184 . 1186 [RFC4206] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP) 1187 Hierarchy with Generalized Multi-Protocol Label Switching 1188 (GMPLS) Traffic Engineering (TE)", RFC 4206, 1189 DOI 10.17487/RFC4206, October 2005, 1190 . 1192 [RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson, 1193 "Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for 1194 Use over an MPLS PSN", RFC 4385, DOI 10.17487/RFC4385, 1195 February 2006, . 1197 [RFC5085] Nadeau, T., Ed. and C. Pignataro, Ed., "Pseudowire Virtual 1198 Circuit Connectivity Verification (VCCV): A Control 1199 Channel for Pseudowires", RFC 5085, DOI 10.17487/RFC5085, 1200 December 2007, . 1202 [RFC5129] Davie, B., Briscoe, B., and J. Tay, "Explicit Congestion 1203 Marking in MPLS", RFC 5129, DOI 10.17487/RFC5129, January 1204 2008, . 1206 [RFC5462] Andersson, L. and R. Asati, "Multiprotocol Label Switching 1207 (MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic 1208 Class" Field", RFC 5462, DOI 10.17487/RFC5462, February 1209 2009, . 1211 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 1212 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 1213 May 2017, . 1215 [RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas, 1216 "Deterministic Networking Architecture", RFC 8655, 1217 DOI 10.17487/RFC8655, October 2019, 1218 . 1220 9.2. Informative References 1222 [I-D.ietf-detnet-data-plane-framework] 1223 Varga, B., Farkas, J., Berger, L., Fedyk, D., Malis, A., 1224 Bryant, S., and J. Korhonen, "DetNet Data Plane 1225 Framework", draft-ietf-detnet-data-plane-framework-03 1226 (work in progress), October 2019. 1228 [I-D.ietf-detnet-ip] 1229 Varga, B., Farkas, J., Berger, L., Fedyk, D., Malis, A., 1230 Bryant, S., and J. Korhonen, "DetNet Data Plane: IP", 1231 draft-ietf-detnet-ip-04 (work in progress), November 2019. 1233 [I-D.ietf-detnet-ip-over-mpls] 1234 Varga, B., Farkas, J., Berger, L., Fedyk, D., Malis, A., 1235 Bryant, S., and J. Korhonen, "DetNet Data Plane: IP over 1236 MPLS", draft-ietf-detnet-ip-over-mpls-04 (work in 1237 progress), November 2019. 1239 [I-D.ietf-detnet-mpls-over-tsn] 1240 Varga, B., Farkas, J., Malis, A., and S. Bryant, "DetNet 1241 Data Plane: MPLS over IEEE 802.1 Time Sensitive Networking 1242 (TSN)", draft-ietf-detnet-mpls-over-tsn-01 (work in 1243 progress), October 2019. 1245 [I-D.ietf-detnet-security] 1246 Mizrahi, T., Grossman, E., Hacker, A., Das, S., Dowdell, 1247 J., Austad, H., and N. Finn, "Deterministic Networking 1248 (DetNet) Security Considerations", draft-ietf-detnet- 1249 security-07 (work in progress), January 2020. 1251 [IEEE802.1AE-2018] 1252 IEEE Standards Association, "IEEE Std 802.1AE-2018 MAC 1253 Security (MACsec)", 2018, 1254 . 1256 [RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S. 1257 Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 1258 Functional Specification", RFC 2205, DOI 10.17487/RFC2205, 1259 September 1997, . 1261 [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, 1262 "Definition of the Differentiated Services Field (DS 1263 Field) in the IPv4 and IPv6 Headers", RFC 2474, 1264 DOI 10.17487/RFC2474, December 1998, 1265 . 1267 [RFC3272] Awduche, D., Chiu, A., Elwalid, A., Widjaja, I., and X. 1268 Xiao, "Overview and Principles of Internet Traffic 1269 Engineering", RFC 3272, DOI 10.17487/RFC3272, May 2002, 1270 . 1272 [RFC3985] Bryant, S., Ed. and P. Pate, Ed., "Pseudo Wire Emulation 1273 Edge-to-Edge (PWE3) Architecture", RFC 3985, 1274 DOI 10.17487/RFC3985, March 2005, 1275 . 1277 [RFC4301] Kent, S. and K. Seo, "Security Architecture for the 1278 Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, 1279 December 2005, . 1281 [RFC4448] Martini, L., Ed., Rosen, E., El-Aawar, N., and G. Heron, 1282 "Encapsulation Methods for Transport of Ethernet over MPLS 1283 Networks", RFC 4448, DOI 10.17487/RFC4448, April 2006, 1284 . 1286 [RFC4875] Aggarwal, R., Ed., Papadimitriou, D., Ed., and S. 1287 Yasukawa, Ed., "Extensions to Resource Reservation 1288 Protocol - Traffic Engineering (RSVP-TE) for Point-to- 1289 Multipoint TE Label Switched Paths (LSPs)", RFC 4875, 1290 DOI 10.17487/RFC4875, May 2007, 1291 . 1293 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 1294 Element (PCE) Communication Protocol (PCEP)", RFC 5440, 1295 DOI 10.17487/RFC5440, March 2009, 1296 . 1298 [RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed., 1299 "MPLS Generic Associated Channel", RFC 5586, 1300 DOI 10.17487/RFC5586, June 2009, 1301 . 1303 [RFC5921] Bocci, M., Ed., Bryant, S., Ed., Frost, D., Ed., Levrau, 1304 L., and L. Berger, "A Framework for MPLS in Transport 1305 Networks", RFC 5921, DOI 10.17487/RFC5921, July 2010, 1306 . 1308 [RFC6003] Papadimitriou, D., "Ethernet Traffic Parameters", 1309 RFC 6003, DOI 10.17487/RFC6003, October 2010, 1310 . 1312 [RFC6073] Martini, L., Metz, C., Nadeau, T., Bocci, M., and M. 1313 Aissaoui, "Segmented Pseudowire", RFC 6073, 1314 DOI 10.17487/RFC6073, January 2011, 1315 . 1317 [RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and 1318 L. Yong, "The Use of Entropy Labels in MPLS Forwarding", 1319 RFC 6790, DOI 10.17487/RFC6790, November 2012, 1320 . 1322 [RFC8306] Zhao, Q., Dhody, D., Ed., Palleti, R., and D. King, 1323 "Extensions to the Path Computation Element Communication 1324 Protocol (PCEP) for Point-to-Multipoint Traffic 1325 Engineering Label Switched Paths", RFC 8306, 1326 DOI 10.17487/RFC8306, November 2017, 1327 . 1329 [RFC8660] Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S., 1330 Decraene, B., Litkowski, S., and R. Shakir, "Segment 1331 Routing with the MPLS Data Plane", RFC 8660, 1332 DOI 10.17487/RFC8660, December 2019, 1333 . 1335 Authors' Addresses 1337 Balazs Varga (editor) 1338 Ericsson 1339 Magyar Tudosok krt. 11. 1340 Budapest 1117 1341 Hungary 1343 Email: balazs.a.varga@ericsson.com 1344 Janos Farkas 1345 Ericsson 1346 Magyar Tudosok krt. 11. 1347 Budapest 1117 1348 Hungary 1350 Email: janos.farkas@ericsson.com 1352 Lou Berger 1353 LabN Consulting, L.L.C. 1355 Email: lberger@labn.net 1357 Don Fedyk 1358 LabN Consulting, L.L.C. 1360 Email: dfedyk@labn.net 1362 Andrew G. Malis 1363 Independent 1365 Email: agmalis@gmail.com 1367 Stewart Bryant 1368 Futurewei Technologies 1370 Email: stewart.bryant@gmail.com 1372 Jouni Korhonen 1374 Email: jouni.nospam@gmail.com