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Jadhav 5 Intended status: Standards Track Huawei Tech 6 Expires: 6 May 2020 M. Gillmore 7 Itron 8 3 November 2019 10 Root initiated routing state in RPL 11 draft-ietf-roll-dao-projection-07 13 Abstract 15 This document proposes a protocol extension to RPL that enables to 16 install a limited amount of centrally-computed routes in a RPL graph, 17 enabling loose source routing down a non-storing mode DODAG, or 18 transversal routes inside the DODAG. As opposed to the classical 19 route injection in RPL that are injected by the end devices, this 20 draft enables the Root of the DODAG to projects the routes that are 21 needed on the nodes where they should be installed. 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 6 May 2020. 40 Copyright Notice 42 Copyright (c) 2019 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 (https://trustee.ietf.org/ 47 license-info) in effect on the date of publication of this document. 48 Please review these documents carefully, as they describe your rights 49 and restrictions with respect to this document. Code Components 50 extracted from this document must include Simplified BSD License text 51 as described in Section 4.e of the Trust Legal Provisions and are 52 provided without warranty as described in the Simplified BSD License. 54 Table of Contents 56 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 57 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 58 2.1. BCP 14 . . . . . . . . . . . . . . . . . . . . . . . . . 4 59 2.2. Subset of a 6LoWPAN Glossary . . . . . . . . . . . . . . 4 60 2.3. Other Terms . . . . . . . . . . . . . . . . . . . . . . . 5 61 2.4. References . . . . . . . . . . . . . . . . . . . . . . . 5 62 3. Extending RFC 6550 . . . . . . . . . . . . . . . . . . . . . 5 63 4. Identifying a Path . . . . . . . . . . . . . . . . . . . . . 6 64 5. New RPL Control Messages and Options . . . . . . . . . . . . 7 65 5.1. New P-DAO Request Control Message . . . . . . . . . . . . 7 66 5.2. New PDR-ACK Control Message . . . . . . . . . . . . . . . 8 67 5.3. Route Projection Options . . . . . . . . . . . . . . . . 8 68 5.4. Sibling Information Option . . . . . . . . . . . . . . . 10 69 6. Projected DAO . . . . . . . . . . . . . . . . . . . . . . . . 12 70 6.1. Non-Storing Mode Projected Route . . . . . . . . . . . . 13 71 6.2. Storing-Mode Projected Route . . . . . . . . . . . . . . 15 72 7. Security Considerations . . . . . . . . . . . . . . . . . . . 17 73 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 74 8.1. New RPL Control Codes . . . . . . . . . . . . . . . . . . 17 75 8.2. Error in Projected Route ICMPv6 Code . . . . . . . . . . 18 76 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18 77 10. Normative References . . . . . . . . . . . . . . . . . . . . 18 78 11. Informative References . . . . . . . . . . . . . . . . . . . 19 79 Appendix A. Applications . . . . . . . . . . . . . . . . . . . . 20 80 A.1. Loose Source Routing in Non-storing Mode . . . . . . . . 20 81 A.2. Transversal Routes in storing and non-storing 82 modes . . . . . . . . . . . . . . . . . . . . . . . . . . 22 83 Appendix B. Examples . . . . . . . . . . . . . . . . . . . . . . 23 84 B.1. Using storing mode P-DAO in non-storing mode MOP . . . . 23 85 B.2. Projecting a storing-mode transversal route . . . . . . . 24 86 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26 88 1. Introduction 90 The "Routing Protocol for Low Power and Lossy Networks" [RFC6550] 91 (LLN)(RPL) is a generic Distance Vector protocol that is well suited 92 for application in a variety of low energy Internet of Things (IoT) 93 networks. RPL forms Destination Oriented Directed Acyclic Graphs 94 (DODAGs) in which the Root often acts as the Border Router to connect 95 the RPL domain to the Internet. The Root is responsible to select 96 the RPL Instance that is used to forward a packet coming from the 97 Internet into the RPL domain and set the related RPL information in 98 the packets. 100 The 6TiSCH architecture [6TiSCH-ARCHI] leverages RPL for its routing 101 operation and considers the Deterministic Networking Architecture 102 [RFC8655] as one possible model whereby the device resources and 103 capabilities are exposed to an external controller which installs 104 routing states into the network based on some objective functions 105 that reside in that external entity. 107 Based on heuristics of usage, path length, and knowledge of device 108 capacity and available resources such as battery levels and 109 reservable buffers, a Path Computation Element ([PCE]) with a global 110 visibility on the system could install additional P2P routes that are 111 more optimized for the current needs as expressed by the objective 112 function. 114 This draft enables a RPL Root to install and maintain Projected 115 Routes within its DODAG, along a selected set of nodes that may or 116 may not include self, for a chosen duration. This potentially 117 enables routes that are more optimized than those obtained with the 118 distributed operation of RPL, either in terms of the size of a 119 source-route header or in terms of path length, which impacts both 120 the latency and the packet delivery ratio. Projected Routes may be 121 installed in either Storing and Non-Storing Modes Instances of the 122 classical RPL operation, resulting in potentially hybrid situations 123 where the mode of some Projected Routes is different from that of the 124 other routes in the RPL Instance. 126 Projected Routes must be used with the parsimony to limit the amount 127 of state that is installed in each device to fit within its 128 resources, and to limit the amount of rerouted traffic to fit within 129 the capabilities of the transmission links. The algorithm used to 130 compute the paths and the protocol used to learn the topology of the 131 network and the resources that are available in devices and in the 132 network are out of scope for this document. Possibly with the 133 assistance of a Path Computation Element ([PCE]) that could have a 134 better visibility on the larger system, the Root computes which 135 segment could be optimized and uses this draft to install the 136 corresponding Projected Routes. 138 A Projected Route may be a stand-alone path to a Target or a segment 139 in a complex Track [6TiSCH-ARCHI] that provides redundant forwarding 140 solutions to a destination to improve reliability and availability of 141 the wireless transmissions [RAW-PS]. 143 2. Terminology 144 2.1. BCP 14 146 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 147 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 148 "OPTIONAL" in this document are to be interpreted as described in BCP 149 14 [RFC2119][RFC8174] when, and only when, they appear in all 150 capitals, as shown here. 152 2.2. Subset of a 6LoWPAN Glossary 154 This document often uses the following acronyms: 156 6BBR: 6LoWPAN Backbone Router 158 6LBR: 6LoWPAN Border Router 160 6LN: 6LoWPAN Node 162 6LR: 6LoWPAN Router 164 DAD: Duplicate Address Detection 166 DODAG: Destination-Oriented Directed Acyclic Graph 168 LLN: Low-Power and Lossy Network 170 NA: Neighbor Advertisement 172 NCE: Neighbor Cache Entry 174 ND: Neighbor Discovery 176 NDP: Neighbor Discovery Protocol 178 NS: Neighbor Solicitation 180 RPL: IPv6 Routing Protocol for LLNs [RFC6550] 182 CMO: Control Message Option 184 DAO: Destination Advertisement Object 186 VIO: A Via Information Option, used in Storing Mode P-DAO messages. 188 SRVIO: A Source-Routed Via Information Option, used in Non-Storing 189 Mode P-DAO messages. 191 RPO: A Route Projection Option; it can be a VIO or an SRVIO. 193 P-DAO: A Projected DAO is a DAO message sent by the RPL Root to 194 install a Projected Route. 196 RTO: RPL Target Option 198 RAN: RPL-Aware Node 200 RA: Router Advertisement 202 RS: Router Solicitation 204 2.3. Other Terms 206 Projected Route: A Projected Route is a serial path that is computed 207 and installed remotely by a RPL Root. 209 Track: The term Track is used in this document to refer to a complex 210 path, e.g., a DODAG, that incorporates redundant Projected Routes 211 towards a destination for increased reliability, high availability 212 and load balancing. 214 2.4. References 216 In this document, readers will encounter terms and concepts that are 217 discussed in the following documents: 219 * "Routing Protocol for Low Power and Lossy Networks" [RFC6550], and 221 * "Terminology in Low power And Lossy Networks" [RFC7102]. 223 3. Extending RFC 6550 225 This specification introduces two new RPL Control Messages to enable 226 a RPL Aware Node (RAN) to request the establisment of a path from 227 self to a Target. A RAN may request the installation of a path by 228 sending a new P-DAO Request PDR) Message to the Root. The Root 229 confirms with a new PDR-ACK message back to the requester RAN with a 230 completion status once it is done installing the path. See 231 Section 5.1 for more. 233 Section 6.7 of [RFC6550] specifies Control Message Options (CMO) to 234 be placed in RPL messages such as the Destination Advertisement 235 Object (DAO) message. The RPL Target Option (RTO) and the Transit 236 Information Option (TIO) are such options. In Non-Storing Mode, the 237 TIO option is used in the DAO message to indicate a parent within a 238 DODAG. The TIO applies to the RTOs that immedially preceed it in the 239 message. Options may be factorized; multiple TIOs may be present to 240 indicate multiple routes to the one or more contiguous addresses 241 indicated in the RTOs that immediately precede the TIOs in the RPL 242 message. 244 This specification introduces two new CMOs referred to as Route 245 Projection Options (RPO) to install Projected Routes. One RPO is the 246 Via Information Option (VIO) and the other is the Source-Routed VIO 247 (SRVIO). The VIO installs a route on each hop along a Projected 248 Route (in a fashion analogous to RPL Storing Mode) whereas the SRVIO 249 installs a source-routing state at the ingress node, which uses that 250 state to insert a routing header in a fashion similar to Non-Storing 251 Mode. Like the TIO, the RPOs MUST be preceded by one or more RTOs to 252 which they apply, and they can be factorized: multiple contiguous 253 RPOs indicate alternate paths to the Target(s), more in Section 5.3. 255 This specification also introduces a new CMO to enable a RPL Router 256 to indicate its siblings to the Root, more in Figure 4. 258 4. Identifying a Path 260 It must be noted that RPL has a concept of Instance to represent 261 different routing topologies but does not have a concept of an 262 administrative distance, which exists in certain proprietary 263 implementations to sort out conflicts between multiple sources of 264 routing information within one routing topology. This draft conforms 265 the Instance model as follows: 267 * If the PCE needs to influence a particular Instance to add better 268 routes in conformance with the routing objectives in that 269 Instance, it may do so as long as it does not create a loop. A 270 Projected Route is always preferred over a route that is learned 271 via RPL. This specification uses the RPL Root as a proxy to the 272 PCE. If the actual PCE is a separate entity, then a protocol that 273 is out of scope for this specification is needed to relay the 274 control elements between the RPL Root and the PCE. 276 * A PCE that installs a more specific (say, Traffic Engineered) and 277 possibly complex path (aka a Track) towards a particular Target 278 MUST use a Local RPL Instance (see section 5 of [RFC6550]) 279 associated to that Target to identify the path. We refer to that 280 Local RPLInstanceID as TrackID. A projected path is uniquely 281 identified within the RPL domain by the tuple (Target address, 282 TrackID). When packet is placed on a Track, a RPL Packet 283 Information (RPI) is added with the TrackID as RPLInstanceID. The 284 RPLInstanceID has the 'D' flag set, indicating that the 285 destination address in the IPv6 header is the Target that is used 286 to identify the Track. 288 * A packet that is routed over a projected path MUST NOT be placed 289 over a different RPL Instance again. A packet that is placed on a 290 Global Instance MAY be injected in a Local Instance based on a 291 network policy and the Local Instance configuration. 293 A Projected Route is a serial path that may the whole path or a 294 segment in a complex Track, in which case multiple Projected Routes 295 are installed with the stuple (Target address, TrackID), and a node 296 that is present on more than one segment in a Track may be able to 297 use either of the Projected Routes to forward towards the Target. 298 The selection of the best route in a Track at forwarding time is out 299 of scope for this document. [RAW-PS] elaborates on that particular 300 problem. 302 5. New RPL Control Messages and Options 304 5.1. New P-DAO Request Control Message 306 The PDR is sent to the Root to request a new Path. Exactly one 307 Target Options MUST be present. 309 The format of P-DAO Request (PDR) Base Object is as follows: 311 0 1 2 3 312 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 1 313 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 314 | RPLInstanceID |K|R| Flags | PDRLifetime | PDRSequence | 315 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 316 | Option(s)... 317 +-+-+-+-+-+-+-+-+ 319 Figure 1: New P-DAO Request Format 321 TrackID: 8-bit field indicating the topology Instance associated 322 with the Track. It is set to zero upon the first request for a 323 new Track and then to the TrackID once the Track was created, to 324 either renew it of destroy it. 326 K: The 'K' flag is set to indicate that the recipient is expected to 327 send a PDR-ACK back. 329 R: The 'R' flag is set to indicate that the Requested path should be 330 redundant. 332 PDRLifetime: 8-bit unsigned integer. The requested lifetime for the 333 Track expressed in Lifetime Units (obtained from the Configuration 334 option). A PDR with a fresher PDRSequence refreshes the lifetime, 335 and a PDRLifetime of 0 indicates that the track should be 336 destroyed. 338 PDRSequence: 8-bit wrapping sequence number. The PDRSequence obeys 339 the operation in section 7.2 of [RFC6550]. It is incremented at 340 each PDR message and echoed in the PDR-ACK by the Root. The 341 PDRSequence is used to correlate a PDR-ACK message with the PDR 342 message that triggeted it. 344 5.2. New PDR-ACK Control Message 346 The new PDR-ACK is sent as a response to a PDR message with the 'K' 347 flag set. Its format is as follows: 349 0 1 2 3 350 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 1 351 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 352 | TrackID | PDR-ACK Status| Flags | Track Lifetime| 353 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 354 | PDRSequence | Reserved | 355 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 356 | Option(s)... 357 +-+-+-+-+-+-+-+ 359 Figure 2: New PDR-ACK Control Message Format 361 TrackID: The RPLInstanceID of the Track that was created. Set to 0 362 when no Track is created. 364 PDR-ACK Status: Indicates the completion. A value up to 127 means 365 acceptance Values of 128 and above are used for rejection codes; 367 Track Lifetime: Indicates that remaining Lifetime for the Track, 0 368 if the Track was destroyed or not created. 370 PDRSequence: 8-bit wrapping sequence number. It is incremented at 371 each PDR message and echoed in the PDR-ACK. 373 5.3. Route Projection Options 375 The RPOs indicate a series of IPv6 addresses that can be compressed 376 using the method defined in the "6LoWPAN Routing Header" [RFC8138] 377 specification using the address of the Root found in the DODAGID 378 field of DIO messages as Compression Reference. 380 An RPO indicates a Projected Route that can be a serial Track in full 381 or a segment of a more complex Track. The Track is identified by a 382 RPLInstanceID that is either Global or local to the Target of the 383 Track. 385 The format of RPOs is as follows: 387 0 1 2 3 388 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 1 389 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 390 | Type | Option Length |Comp.| Flags | TrackID | 391 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 392 | Path Lifetime | Path Sequence | Reserved | 393 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 394 | | 395 + + 396 . . 397 . Via Address 1 . 398 . . 399 + + 400 | | 401 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 402 | | 403 . .... . 404 | | 405 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 406 | | 407 + + 408 . . 409 . Via Address n . 410 . . 411 + + 412 | | 413 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 415 Figure 3: Via Information option format 417 Option Type: 0x0A for VIO, 0x0B for SRVIO (to be confirmed by IANA) 419 Option Length: In bytes; variable, depending on the number of Via 420 Addresses. 422 Compression Type: 16-bit unsigned integer. This is the SRH-6LoRH 423 Type as defined in figure 7 in section 5.1 of [RFC8138] that 424 corresponds to the compression used for all the Via Addresses. 426 TrackID: 8-bit field indicating the topology Instance associated 427 with the Track. 429 Path Lifetime: 8-bit unsigned integer. The length of time in 430 Lifetime Units (obtained from the Configuration option) that the 431 prefix is valid for route determination. The period starts when a 432 new Path Sequence is seen. A value of 255 (0xFF) represents 433 infinity. A value of zero (0x00) indicates a loss of 434 reachability. A DAO message that contains a Via Information 435 option with a Path Lifetime of zero for a Target is referred as a 436 No-Path (for that Target) in this document. 438 Path Sequence: 8-bit unsigned integer. When a RPL Target option is 439 issued by the Root of the DODAG (i.e. in a DAO message), that Root 440 sets the Path Sequence and increments the Path Sequence each time 441 it issues a RPL Target option with updated information. The 442 indicated sequence deprecates any state for a given Target that 443 was learned from a previous sequence and adds to any state that 444 was learned for that sequence. 446 Via Address: 2 to 16 bytes, a compressed IPv6 Address. A Via 447 Address indicates the next hop within the path towards the 448 destination(s) that is indicated in the Target option that 449 immediately precede the RPO in the DAO message. Via Addresses are 450 indicated in the order of the path from the ingress to the egress 451 nodes. All Via addresses are expressed in the same size as 452 indicated by the Compression Type. 454 An RPO MUST contain at least one Via Address, and a Via Address MUST 455 NOT be present more than once, otherwise the RPO MUST be ignored. 457 5.4. Sibling Information Option 459 The Sibling Information Option (SIO) provides indication on siblings 460 that could be used by the Root to form Projected Routes. The format 461 of SIOs is as follows: 463 0 1 2 3 464 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 1 465 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 466 | Type | Option Length |Comp.|B| Flags | Opaque | 467 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 468 | Step of Rank | Reserved | 469 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 470 | | 471 + + 472 . . 473 . Sibling Address . 474 . . 475 + + 476 | | 477 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 479 Figure 4: Sibling Information Option Format 481 Option Type: 0x0C (to be confirmed by IANA) 483 Option Length: In bytes; variable, depending on the number of Via 484 Addresses. 486 Compression Type: 16-bit unsigned integer. This is the SRH-6LoRH 487 Type as defined in figure 7 in section 5.1 of [RFC8138] that 488 corresponds to the compression used for the Sibling Address. 490 B: 1-bit flag that is set to indicate that the connectivity to the 491 sibling is bidirectional and roughly symmetrical. In that case, 492 only one of the siblings may report the SIO for the hop. If 'B' 493 is not set then the SIO only indicates connectivity from the 494 sibling to this node, and does not provide information on the hop 495 from this node to the sibling. 497 Opaque: MAY be used to carry information that the node and the Root 498 understand, e.g., a particular representation of the Link 499 properties such as a proprietary Link Quality Information for 500 packets received from the sibling. An industraial Alliance that 501 uses RPL for a particular use / environment MAY redefine the use 502 of this field to fit its needs. 504 Step of Rank: 16-bit unsigned integer. This is the Step of Rank 505 [RFC6550] as computed by the Objective Function between this node 506 and the sibling. 508 Reserved: MUST be set to zero by the sender and MUST be ignored by 509 the receiver. 511 Sibling Address: 2 to 16 bytes, a compressed IPv6 Address. a Via 512 Address indicates the next hop towards the destination(s) that is 513 indicated in the Target option that immediately precede the RPO in 514 the DAO message. Via Addresses are indicated in the order of the 515 data path from the ingress to the egress nodes. All Via addresses 516 are expressed in the same size as indicated by the Compression 517 Type 519 An SIO MAY be immediately followed by a DAG Metric Container. In 520 that case the DAG Metric Container provides additional metrics for 521 the hop from the Sibling to this node. 523 6. Projected DAO 525 This draft adds a capability to RPL whereby the Root of a DODAG 526 projects a route by sending an extended DAO message called a 527 Projected-DAO (P-DAO) to an arbitrary router in the DODAG, indicating 528 one or more sequence(s) of routers inside the DODAG via which the 529 Target(s) indicated in the RPL Target Option(s) (RTO) can be reached. 531 A P-DAO is sent from a global address of the Root to a global address 532 of the recipient, and MUST be confirmed by a DAO-ACK, which is sent 533 back to a global address of the Root. 535 A P-DAO message MUST contain at least one RTO and at least one RPO 536 following it. There can be at most one such sequence of RTOs and 537 then RPOs. 539 Like a classical DAO message, a P-DAO is processed only if it is 540 "new" per section 9.2.2. "Generation of DAO Messages" of the RPL 541 specification [RFC6550]; this is determined using the Path Sequence 542 information from the RPO as opposed to a TIO. Also, a Path Lifetime 543 of 0 in an RPO indicates that a route is to be removed. 545 There are two kinds of operation for the Projected Routes, the 546 Storing Mode and the Non-Storing Mode. 548 * The Non-Storing Mode is discussed in Section 6.1. It uses an 549 SRVIO that carries a list of Via Addresses to be used as a source- 550 routed path to the Target. The recipient of the P-DAO is the 551 ingress router of the source-routed path. Upon a Non-Storing Mode 552 P-DAO, the ingress router installs a source-routed state to the 553 Target and replies to the Root directly with a DAO-ACK message. 555 * The Storing Mode is discussed in Section 6.2. It uses a VIO with 556 one Via Address per consecutive hop, from the ingress to the 557 egress of the path, including the list of all intermediate routers 558 in the data path order. The Via Addresses indicate the routers in 559 which the routing state to the Target have to be installed via the 560 next Via Address in the VIO. In normal operations, the P-DAO is 561 propagated along the chain of Via Routers from the egress router 562 of the path till the ingress one, which confirms the installation 563 to the Root with a DAO-ACK message. Note that the Root may be the 564 ingress and it may be the egress of the path, that it can also be 565 neither but it cannot be both. 567 In case of a forwarding error along a Projected Route, an ICMP error 568 is sent to the Root with a new Code "Error in Projected Route" (See 569 Section 8.2). The Root can then modify or remove the Projected 570 Route. The "Error in Projected Route" message has the same format as 571 the "Destination Unreachable Message", as specified in RFC 4443 572 [RFC4443]. The portion of the invoking packet that is sent back in 573 the ICMP message SHOULD record at least up to the routing header if 574 one is present, and the routing header SHOULD be consumed by this 575 node so that the destination in the IPv6 header is the next hop that 576 this node could not reach. if a 6LoWPAN Routing Header (6LoRH) 577 [RFC8138] is used to carry the IPv6 routing information in the outter 578 header then that whole 6LoRH information SHOULD be present in the 579 ICMP message. The sender and exact operation depend on the Mode and 580 is described in Section 6.1 and Section 6.2 respectively. 582 6.1. Non-Storing Mode Projected Route 584 As illustrated in Figure 5, a P-DAO that carries an SRVIO enables the 585 Root to install a source-routed path towards a Target in any 586 particular router; with this path information the router can add a 587 source routed header reflecting the Projected Route to any packet for 588 which the current destination either is the said Target or can be 589 reached via the Target. 591 ------+--------- 592 | Internet 593 | 594 +-----+ 595 | | Border Router 596 | | (RPL Root) 597 +-----+ | P ^ | 598 | | DAO | ACK | Loose 599 o o o o router V | | Source 600 o o o o o o o o o | P-DAO . Route 601 o o o o o o o o o o | Source . Path 602 o o o o o o o o o | Route . From 603 o o o o o o o o | Path . Root 604 o o o o o Target V . To 605 o o o o | Desti- 606 o o o o | nation 607 destination V 609 LLN 611 Figure 5: Projecting a Non-Storing Route 613 A route indicated by an SRVIO may be loose, meaning that the node 614 that owns the next listed Via Address is not necessarily a neighbor. 615 Without proper loop avoidance mechanisms, the interaction of loose 616 source routing and other mechanisms may effectively cause loops. In 617 order to avoid those loops, if the router that installs a Projected 618 Route does not have a connected route (a direct adjacency) to the 619 next soure routed hop and fails to locate it as a neighbor or a 620 neighbor of a neighbor, then it MUST ensure that it has another 621 Projected Route to the next loose hop under the control of the same 622 route computation system, otherwise the P-DAO is rejected. 624 When forwarding a packet to a destination for which the router 625 determines that routing happens via the Target, the router inserts 626 the source routing header in the packet to reach the Target. In the 627 case of a loose source-routed path, there MUST be either a neighbor 628 that is adjacent to the loose next hop, on which case the packet s 629 forwarded to that neighbor, or a source-routed path to the loose next 630 hop; in the latter case, another encapsulation takes place and the 631 process possibly recurses; otherwise the packet is dropped. 633 In order to add a source-routing header, the router encapsulates the 634 packet with an IP-in-IP header and a non-storing mode source routing 635 header (SRH) [RFC6554]. In the uncompressed form the source of the 636 packet would be self, the destination would be the first Via Address 637 in the SRVIO, and the SRH would contain the list of the remaining Via 638 Addresses and then the Target. 640 In practice, the router will normally use the "IPv6 over Low-Power 641 Wireless Personal Area Network (6LoWPAN) Paging Dispatch" [RFC8025] 642 to compress the RPL artifacts as indicated in [RFC8138]. In that 643 case, the router indicates self as encapsulator in an IP-in-IP 6LoRH 644 Header, and places the list of Via Addresses in the order of the VIO 645 and then the Target in the SRH 6LoRH Header. 647 In case of a forwarding error along a Source Route path, the node 648 that fails to forward SHOULD send an ICMP error with a code "Error in 649 Source Routing Header" back to the source of the packet, as described 650 in section 11.2.2.3. of [RFC6550]. Upon this message, the 651 encapsulating node SHOULD stop using the source route path for a 652 period of time and it SHOULD send an ICMP message with a Code "Error 653 in Projected Route" to the Root. Failure to follow these steps may 654 result in packet loss and wasted resources along the source route 655 path that is broken. 657 6.2. Storing-Mode Projected Route 659 As illustrated in Figure 6, the Storing Mode route projection is used 660 by the Root to install a routing state towards a Target in the 661 routers along a segment between an ingress and an egress router; this 662 enables the routers to forward along that segment any packet for 663 which the next loose hop is the said Target, for Instance a loose 664 source routed packet for which the next loose hop is the Target, or a 665 packet for which the router has a routing state to the final 666 destination via the Target. 668 ------+--------- 669 | Internet 670 | 671 +-----+ 672 | | Border Router 673 | | (RPL Root) 674 +-----+ | ^ | 675 | | DAO | ACK | 676 o o o o | | | 677 o o o o o o o o o | ^ | Projected . 678 o o o o o o o o o o | | DAO | Route . 679 o o o o o o o o o | ^ | . 680 o o o o o o o o v | DAO v . 681 o o LLN o o o | 682 o o o o o Loose Source Route Path | 683 o o o o From Root To Destination v 685 Figure 6: Projecting a route 687 In order to install the relevant routing state along the segment 688 between an ingress and an egress routers, the Root sends a unicast 689 P-DAO message to the egress router of the routing segment that must 690 be installed. The P-DAO message contains the ordered list of hops 691 along the segment as a direct sequence of Via Information options 692 that are preceded by one or more RPL Target options to which they 693 relate. Each Via Information option contains a Path Lifetime for 694 which the state is to be maintained. 696 The Root sends the P-DAO directly to the egress node of the segment. 697 In that P-DAO, the destination IP address matches the Via Address in 698 the last VIO. This is how the egress recognizes its role. In a 699 similar fashion, the ingress node recognizes its role as it matches 700 Via Address in the first VIO. 702 The egress node of the segment is the only node in the path that does 703 not install a route in response to the P-DAO; it is expected to be 704 already able to route to the Target(s) on its own. It may either be 705 the Target, or may have some existing information to reach the 706 Target(s), such as a connected route or an already installed 707 Projected Route. If one of the Targets cannot be located, the node 708 MUST answer to the Root with a negative DAO-ACK listing the Target(s) 709 that could not be located (suggested status 10 to be confirmed by 710 IANA). 712 If the egress node can reach all the Targets, then it forwards the 713 P-DAO with unchanged content to its loose predecessor in the segment 714 as indicated in the list of Via Information options, and recursively 715 the message is propagated unchanged along the sequence of routers 716 indicated in the P-DAO, but in the reverse order, from egress to 717 ingress. 719 The address of the predecessor to be used as destination of the 720 propagated DAO message is found in the Via Information option the 721 precedes the one that contain the address of the propagating node, 722 which is used as source of the packet. 724 Upon receiving a propagated DAO, an intermediate router as well as 725 the ingress router install a route towards the DAO Target(s) via its 726 successor in the P-DAO; the router locates the VIO that contains its 727 address, and uses as next hop the address found in the Via Address 728 field in the following VIO. The router MAY install additional routes 729 towards the addresses that are located in VIOs that are after the 730 next one, if any, but in case of a conflict or a lack of resource, a 731 route to a Target installed by the Root has precedence. 733 The process recurses till the P-DAO is propagated to ingress router 734 of the segment, which answers with a DAO-ACK to the Root. 736 Also, the path indicated in a P-DAO may be loose, in which case the 737 reachability to the next hop has to be asserted. Each router along 738 the path indicated in a P-DAO is expected to be able to reach its 739 successor, either with a connected route (direct neighbor), or by 740 routing, for Instance following a route installed previously by a DAO 741 or a P-DAO message. If that route is not connected then a recursive 742 lookup may take place at packet forwarding time to find the next hop 743 to reach the Target(s). If it does not and cannot reach the next 744 router in the P-DAO, the router MUST answer to the Root with a 745 negative DAO-ACK indicating the successor that is unreachable 746 (suggested status 11 to be confirmed by IANA). 748 A Path Lifetime of 0 in a Via Information option is used to clean up 749 the state. The P-DAO is forwarded as described above, but the DAO is 750 interpreted as a No-Path DAO and results in cleaning up existing 751 state as opposed to refreshing an existing one or installing a new 752 one. 754 In case of a forwarding error along a Storing Mode Projected Route, 755 the node that fails to forward SHOULD send an ICMP error with a code 756 "Error in Projected Route" to the Root. Failure to do so may result 757 in packet loss and wasted resources along the Projected Route that is 758 broken. 760 7. Security Considerations 762 This draft uses messages that are already present in RPL [RFC6550] 763 with optional secured versions. The same secured versions may be 764 used with this draft, and whatever security is deployed for a given 765 network also applies to the flows in this draft. 767 TODO: should probably consider how P-DAO messages could be abused by 768 a) rogue nodes b) via replay of messages c) if use of P-DAO messages 769 could in fact deal with any threats? 771 8. IANA Considerations 773 8.1. New RPL Control Codes 775 This document extends the IANA registry created by RFC 6550 for RPL 776 Control Codes as follows: 778 +------+--------------------------------------+---------------+ 779 | Code | Description | Reference | 780 +======+======================================+===============+ 781 | 0x0A | Via Information option | This document | 782 +------+--------------------------------------+---------------+ 783 | 0x0B | Source-Routed Via Information option | This document | 784 +------+--------------------------------------+---------------+ 786 Table 1: RPL Control Codes 788 This document is updating the registry created by RFC 6550 for the 789 RPL 3-bit Mode of Operation (MOP) as follows: 791 +-----------+-------------------------------+-----------+ 792 | MOP value | Description | Reference | 793 +===========+===============================+===========+ 794 | 5 | Non-Storing mode of operation | This | 795 | | with Projected Routes | document | 796 +-----------+-------------------------------+-----------+ 797 | 6 | Storing mode of operation | This | 798 | | with Projected Routes | document | 799 +-----------+-------------------------------+-----------+ 801 Table 2: DIO Mode of operation 803 8.2. Error in Projected Route ICMPv6 Code 805 In some cases RPL will return an ICMPv6 error message when a message 806 cannot be forwarded along a Projected Route. This ICMPv6 error 807 message is "Error in Projected Route". 809 IANA has defined an ICMPv6 "Code" Fields Registry for ICMPv6 Message 810 Types. ICMPv6 Message Type 1 describes "Destination Unreachable" 811 codes. This specification requires that a new code is allocated from 812 the ICMPv6 Code Fields Registry for ICMPv6 Message Type 1, for "Error 813 in Projected Route", with a suggested code value of 8, to be 814 confirmed by IANA. 816 9. Acknowledgments 818 The authors wish to acknowledge JP Vasseur, James Pylakutty and 819 Patrick Wetterwald for their contributions to the ideas developed 820 here. 822 10. Normative References 824 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 825 Requirement Levels", BCP 14, RFC 2119, 826 DOI 10.17487/RFC2119, March 1997, 827 . 829 [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet 830 Control Message Protocol (ICMPv6) for the Internet 831 Protocol Version 6 (IPv6) Specification", STD 89, 832 RFC 4443, DOI 10.17487/RFC4443, March 2006, 833 . 835 [RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J., 836 Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur, 837 JP., and R. Alexander, "RPL: IPv6 Routing Protocol for 838 Low-Power and Lossy Networks", RFC 6550, 839 DOI 10.17487/RFC6550, March 2012, 840 . 842 [RFC6554] Hui, J., Vasseur, JP., Culler, D., and V. Manral, "An IPv6 843 Routing Header for Source Routes with the Routing Protocol 844 for Low-Power and Lossy Networks (RPL)", RFC 6554, 845 DOI 10.17487/RFC6554, March 2012, 846 . 848 [RFC8025] Thubert, P., Ed. and R. Cragie, "IPv6 over Low-Power 849 Wireless Personal Area Network (6LoWPAN) Paging Dispatch", 850 RFC 8025, DOI 10.17487/RFC8025, November 2016, 851 . 853 [RFC8138] Thubert, P., Ed., Bormann, C., Toutain, L., and R. Cragie, 854 "IPv6 over Low-Power Wireless Personal Area Network 855 (6LoWPAN) Routing Header", RFC 8138, DOI 10.17487/RFC8138, 856 April 2017, . 858 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 859 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 860 May 2017, . 862 11. Informative References 864 [RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and 865 Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January 866 2014, . 868 [RFC6997] Goyal, M., Ed., Baccelli, E., Philipp, M., Brandt, A., and 869 J. Martocci, "Reactive Discovery of Point-to-Point Routes 870 in Low-Power and Lossy Networks", RFC 6997, 871 DOI 10.17487/RFC6997, August 2013, 872 . 874 [6TiSCH-ARCHI] 875 Thubert, P., "An Architecture for IPv6 over the TSCH mode 876 of IEEE 802.15.4", Work in Progress, Internet-Draft, 877 draft-ietf-6tisch-architecture-27, 18 October 2019, 878 . 881 [RAW-PS] Thubert, P. and G. Papadopoulos, "Reliable and Available 882 Wireless Problem Statement", Work in Progress, Internet- 883 Draft, draft-pthubert-raw-problem-statement-04, 23 October 884 2019, . 887 [RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas, 888 "Deterministic Networking Architecture", RFC 8655, 889 DOI 10.17487/RFC8655, October 2019, 890 . 892 [PCE] IETF, "Path Computation Element", November 2019, 893 . 895 Appendix A. Applications 897 A.1. Loose Source Routing in Non-storing Mode 899 A RPL implementation operating in a very constrained LLN typically 900 uses the Non-Storing Mode of Operation as represented in Figure 7. 901 In that mode, a RPL node indicates a parent-child relationship to the 902 Root, using a Destination Advertisement Object (DAO) that is unicast 903 from the node directly to the Root, and the Root typically builds a 904 source routed path to a destination down the DODAG by recursively 905 concatenating this information. 907 ------+--------- 908 | Internet 909 | 910 +-----+ 911 | | Border Router 912 | | (RPL Root) 913 +-----+ ^ | | 914 | | DAO | ACK | 915 o o o o | | | Strict 916 o o o o o o o o o | | | Source 917 o o o o o o o o o o | | | Route 918 o o o o o o o o o | | | 919 o o o o o o o o | v v 920 o o o o 921 LLN 923 Figure 7: RPL non-storing mode of operation 925 Based on the parent-children relationships expressed in the non- 926 storing DAO messages,the Root possesses topological information about 927 the whole network, though this information is limited to the 928 structure of the DODAG for which it is the destination. A packet 929 that is generated within the domain will always reach the Root, which 930 can then apply a source routing information to reach the destination 931 if the destination is also in the DODAG. Similarly, a packet coming 932 from the outside of the domain for a destination that is expected to 933 be in a RPL domain reaches the Root. 935 It results that the Root, or then some associated centralized 936 computation engine such as a PCE, can determine the amount of packets 937 that reach a destination in the RPL domain, and thus the amount of 938 energy and bandwidth that is wasted for transmission, between itself 939 and the destination, as well as the risk of fragmentation, any 940 potential delays because of a paths longer than necessary (shorter 941 paths exist that would not traverse the Root). 943 As a network gets deep, the size of the source routing header that 944 the Root must add to all the downward packets becomes an issue for 945 nodes that are many hops away. In some use cases, a RPL network 946 forms long lines and a limited amount of well-Targeted routing state 947 would allow to make the source routing operation loose as opposed to 948 strict, and save packet size. Limiting the packet size is directly 949 beneficial to the energy budget, but, mostly, it reduces the chances 950 of frame loss and/or packet fragmentation, which is highly 951 detrimental to the LLN operation. Because the capability to store a 952 routing state in every node is limited, the decision of which route 953 is installed where can only be optimized with a global knowledge of 954 the system, a knowledge that the Root or an associated PCE may 955 possess by means that are outside of the scope of this specification. 957 This specification enables to store source-routed or storing mode 958 state in intermediate routers, which enables to limit the excursion 959 of the source route headers in deep networks. Once a P-DAO exchange 960 has taken place for a given Target, if the Root operates in non 961 storing mode, then it may elide the sequence of routers that is 962 installed in the network from its source route headers to destination 963 that are reachable via that Target, and the source route headers 964 effectively become loose. 966 A.2. Transversal Routes in storing and non-storing modes 968 RPL is optimized for Point-to-Multipoint (P2MP) and Multipoint-to- 969 Point (MP2P), whereby routes are always installed along the RPL DODAG 970 respectively from and towards the DODAG Root. Transversal Peer to 971 Peer (P2P) routes in a RPL network will generally suffer from some 972 elongated (stretched) path versus the best possible path, since 973 routing between 2 nodes always happens via a common parent, as 974 illustrated in Figure 8: 976 * in non-storing mode, all packets routed within the DODAG flow all 977 the way up to the Root of the DODAG. If the destination is in the 978 same DODAG, the Root must encapsulate the packet to place a 979 Routing Header that has the strict source route information down 980 the DODAG to the destination. This will be the case even if the 981 destination is relatively close to the source and the Root is 982 relatively far off. 984 * In storing mode, unless the destination is a child of the source, 985 the packets will follow the default route up the DODAG as well. 986 If the destination is in the same DODAG, they will eventually 987 reach a common parent that has a route to the destination; at 988 worse, the common parent may also be the Root. From that common 989 parent, the packet will follow a path down the DODAG that is 990 optimized for the Objective Function that was used to build the 991 DODAG. 993 ------+--------- 994 | Internet 995 | 996 +-----+ 997 | | Border Router 998 | | (RPL Root) 999 +-----+ 1000 X 1001 ^ v o o 1002 ^ o o v o o o o o 1003 ^ o o o v o o o o o 1004 ^ o o v o o o o o 1005 S o o o D o o o 1006 o o o o 1007 LLN 1009 Figure 8: Routing Stretch between S and D via common parent X 1011 It results that it is often beneficial to enable transversal P2P 1012 routes, either if the RPL route presents a stretch from shortest 1013 path, or if the new route is engineered with a different objective. 1014 For that reason, earlier work at the IETF introduced the "Reactive 1015 Discovery of Point-to-Point Routes in Low Power and Lossy Networks" 1016 [RFC6997], which specifies a distributed method for establishing 1017 optimized P2P routes. This draft proposes an alternate based on a 1018 centralized route computation. 1020 ------+--------- 1021 | Internet 1022 | 1023 +-----+ 1024 | | Border Router 1025 | | (RPL Root) 1026 +-----+ 1027 | 1028 o o o o 1029 o o o o o o o o o 1030 o o o o o o o o o o 1031 o o o o o o o o o 1032 S>>A>>>B>>C>>>D o o o 1033 o o o o 1034 LLN 1036 Figure 9: Projected Transversal Route 1038 This specification enables to store source-routed or storing mode 1039 state in intermediate routers, which enables to limit the stretch of 1040 a P2P route and maintain the characteristics within a given SLA. An 1041 example of service using this mechanism oculd be a control loop that 1042 would be installed in a network that uses classical RPL for 1043 asynchronous data collection. In that case, the P2P path may be 1044 installed in a different RPL Instance, with a different objective 1045 function. 1047 Appendix B. Examples 1049 B.1. Using storing mode P-DAO in non-storing mode MOP 1051 In non-storing mode, the DAG Root maintains the knowledge of the 1052 whole DODAG topology, so when both the source and the destination of 1053 a packet are in the DODAG, the Root can determine the common parent 1054 that would have been used in storing mode, and thus the list of nodes 1055 in the path between the common parent and the destination. For 1056 Instance in the diagram shown in Figure 10, if the source is node 41 1057 and the destination is node 52, then the common parent is node 22. 1059 ------+--------- 1060 | Internet 1061 | 1062 +-----+ 1063 | | Border Router 1064 | | (RPL Root) 1065 +-----+ 1066 | \ \____ 1067 / \ \ 1068 o 11 o 12 o 13 1069 / | / \ 1070 o 22 o 23 o 24 o 25 1071 / \ | \ \ 1072 o 31 o 32 o o o 35 1073 / / | \ | \ 1074 o 41 o 42 o o o 45 o 46 1075 | | | | \ | 1076 o 51 o 52 o 53 o o 55 o 56 1078 LLN 1080 Figure 10: Example DODAG forming a logical tree topology 1082 With this draft, the Root can install a storing mode routing states 1083 along a segment that is either from itself to the destination, or 1084 from one or more common parents for a particular source/destination 1085 pair towards that destination (in this particular example, this would 1086 be the segment made of nodes 22, 32, 42). 1088 In the example below, say that there is a lot of traffic to nodes 55 1089 and 56 and the Root decides to reduce the size of routing headers to 1090 those destinations. The Root can first send a DAO to node 45 1091 indicating Target 55 and a Via segment (35, 45), as well as another 1092 DAO to node 46 indicating Target 56 and a Via segment (35, 46). This 1093 will save one entry in the routing header on both sides. The Root 1094 may then send a DAO to node 35 indicating Targets 55 and 56 a Via 1095 segment (13, 24, 35) to fully optimize that path. 1097 Alternatively, the Root may send a DAO to node 45 indicating Target 1098 55 and a Via segment (13, 24, 35, 45) and then a DAO to node 46 1099 indicating Target 56 and a Via segment (13, 24, 35, 46), indicating 1100 the same DAO Sequence. 1102 B.2. Projecting a storing-mode transversal route 1104 In this example, say that a PCE determines that a path must be 1105 installed between node S and node D via routers A, B and C, in order 1106 to serve the needs of a particular application. 1108 The Root sends a P-DAO with a Target option indicating the 1109 destination D and a sequence Via Information option, one for S, which 1110 is the ingress router of the segment, one for A and then for B, which 1111 are an intermediate routers, and one for C, which is the egress 1112 router. 1114 ------+--------- 1115 | Internet 1116 | 1117 +-----+ 1118 | | Border Router 1119 | | (RPL Root) 1120 +-----+ 1121 | P-DAO message to C 1122 o | o o 1123 o o o | o o o o o 1124 o o o | o o o o o o 1125 o o V o o o o o o 1126 S A B C D o o o 1127 o o o o 1128 LLN 1130 Figure 11: P-DAO from Root 1132 Upon reception of the P-DAO, C validates that it can reach D, e.g. 1133 using IPv6 Neighbor Discovery, and if so, propagates the P-DAO 1134 unchanged to B. 1136 B checks that it can reach C and of so, installs a route towards D 1137 via C. Then it propagates the P-DAO to A. 1139 The process recurses till the P-DAO reaches S, the ingress of the 1140 segment, which installs a route to D via A and sends a DAO-ACK to the 1141 Root. 1143 ------+--------- 1144 | Internet 1145 | 1146 +-----+ 1147 | | Border Router 1148 | | (RPL Root) 1149 +-----+ 1150 ^ P-DAO-ACK from S 1151 / o o o 1152 / o o o o o o o 1153 | o o o o o o o o o 1154 | o o o o o o o o 1155 S A B C D o o o 1156 o o o o 1157 LLN 1159 Figure 12: P-DAO-ACK to Root 1161 As a result, a transversal route is installed that does not need to 1162 follow the DODAG structure. 1164 ------+--------- 1165 | Internet 1166 | 1167 +-----+ 1168 | | Border Router 1169 | | (RPL Root) 1170 +-----+ 1171 | 1172 o o o o 1173 o o o o o o o o o 1174 o o o o o o o o o o 1175 o o o o o o o o o 1176 S>>A>>>B>>C>>>D o o o 1177 o o o o 1178 LLN 1180 Figure 13: Projected Transversal Route 1182 Authors' Addresses 1184 Pascal Thubert (editor) 1185 Cisco Systems, Inc 1186 Building D, 45 Allee des Ormes - BP1200 1187 06254 Mougins - Sophia Antipolis 1188 France 1190 Phone: +33 497 23 26 34 1191 Email: pthubert@cisco.com 1193 Rahul Arvind Jadhav 1194 Huawei Tech 1195 Kundalahalli Village, Whitefield, 1196 Bangalore 560037 1197 Karnataka 1198 India 1200 Phone: +91-080-49160700 1201 Email: rahul.ietf@gmail.com 1203 Matthew Gillmore 1204 Itron, Inc 1205 Building D, 2111 N Molter Road 1206 Liberty Lake, 99019 1207 United States 1209 Phone: +1.800.635.5461 1210 Email: matthew.gillmore@itron.com