idnits 2.17.1 draft-ietf-dots-use-cases-20.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (September 05, 2019) is 1692 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Outdated reference: A later version (-13) exists of draft-ietf-dots-multihoming-02 Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 DOTS R. Dobbins 3 Internet-Draft Arbor Networks 4 Intended status: Informational D. Migault 5 Expires: March 8, 2020 Ericsson 6 R. Moskowitz 7 HTT Consulting 8 N. Teague 9 Iron Mountain Data Centers 10 L. Xia 11 Huawei 12 K. Nishizuka 13 NTT Communications 14 September 05, 2019 16 Use cases for DDoS Open Threat Signaling 17 draft-ietf-dots-use-cases-20 19 Abstract 21 The DDoS Open Threat Signaling (DOTS) effort is intended to provide 22 protocols to facilitate interoperability across disparate DDoS 23 mitigation solutions. This document presents sample use cases which 24 describe the interactions expected between the DOTS components as 25 well as DOTS messaging exchanges. These use cases are meant to 26 identify the interacting DOTS components, how they collaborate, and 27 what are the typical information to be exchanged. 29 Status of This Memo 31 This Internet-Draft is submitted in full conformance with the 32 provisions of BCP 78 and BCP 79. 34 Internet-Drafts are working documents of the Internet Engineering 35 Task Force (IETF). Note that other groups may also distribute 36 working documents as Internet-Drafts. The list of current Internet- 37 Drafts is at https://datatracker.ietf.org/drafts/current/. 39 Internet-Drafts are draft documents valid for a maximum of six months 40 and may be updated, replaced, or obsoleted by other documents at any 41 time. It is inappropriate to use Internet-Drafts as reference 42 material or to cite them other than as "work in progress." 44 This Internet-Draft will expire on March 8, 2020. 46 Copyright Notice 48 Copyright (c) 2019 IETF Trust and the persons identified as the 49 document authors. All rights reserved. 51 This document is subject to BCP 78 and the IETF Trust's Legal 52 Provisions Relating to IETF Documents 53 (https://trustee.ietf.org/license-info) in effect on the date of 54 publication of this document. Please review these documents 55 carefully, as they describe your rights and restrictions with respect 56 to this document. Code Components extracted from this document must 57 include Simplified BSD License text as described in Section 4.e of 58 the Trust Legal Provisions and are provided without warranty as 59 described in the Simplified BSD License. 61 Table of Contents 63 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 64 2. Terminology and Acronyms . . . . . . . . . . . . . . . . . . 3 65 3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 3 66 3.1. Upstream DDoS Mitigation by an Upstream Internet Transit 67 Provider . . . . . . . . . . . . . . . . . . . . . . . . 3 68 3.2. DDoS Mitigation by a Third Party DDoS Mitigation Service 69 Provider . . . . . . . . . . . . . . . . . . . . . . . . 7 70 3.3. DDoS Orchestration . . . . . . . . . . . . . . . . . . . 9 71 4. Security Considerations . . . . . . . . . . . . . . . . . . . 13 72 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 73 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13 74 7. Informative References . . . . . . . . . . . . . . . . . . . 13 75 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 77 1. Introduction 79 At the time of writing, distributed denial-of-service (DDoS) attack 80 mitigation solutions are largely based upon siloed, proprietary 81 communications schemes with vendor lock-in as a side-effect. This 82 can result in the configuration, provisioning, operation, and 83 activation of these solutions being a highly manual and often time- 84 consuming process. Additionally, coordinating multiple DDoS 85 mitigation solutions simultaneously is fraught with both technical 86 and process-related hurdles. This greatly increases operational 87 complexity which, in turn, can degrade the efficacy of mitigations. 89 The DDoS Open Threat Signaling (DOTS) effort is intended to specify 90 protocols that facilitate interoperability between diverse DDoS 91 mitigation solutions and ensure greater integration in term of attack 92 detection, mitigation requests, and attack characterization patterns. 93 As DDoS solutions are broadly heterogeneous among vendors, the 94 primary goal of DOTS is to provide high-level interaction amongst 95 differing DDoS solutions, such as detecting, initiating, terminating 96 DDoS mitigation assistance or requesting the status of a DDoS 97 mitigation. 99 This document provides sample use cases to provide inputs for the 100 design of the DOTS protocols. The use cases are not exhaustive and 101 future use cases are expected to emerge as DOTS is adopted and 102 evolves. 104 2. Terminology and Acronyms 106 This document makes use of the same terminology and definitions as 107 [RFC8612]. In addition it uses the terms defined below: 109 o DDoS Mitigation Service Provider: designates the administrative 110 entity providing the DDoS Mitigation Service. 112 o DDoS Mitigation System (DMS): A system that performs DDoS 113 mitigation. The DDoS Mitigation System may be composed by a 114 cluster of hardware and/or software resources, but could also 115 involve an orchestrator that may take decisions such as 116 outsourcing partial or more of the mitigation to another DDoS 117 Mitigation System. 119 o DDoS Mitigation: The action performed by the DDoS Mitigation 120 System. 122 o DDoS Mitigation Service: designates a service provided to a 123 customer to mitigate DDoS attacks. Service subscriptions usually 124 involve Service Level Agreement (SLA) that have to be met. It is 125 the responsibility of the DDoS Service provider to instantiate the 126 DDoS Mitigation System to meet these SLAs. 128 o Internet Transit Provider (ITP): designates the entity that 129 delivers the traffic to a customer network. It can be an Internet 130 Service Provider (ISP), or an upstream entity delivering the 131 traffic to the ISP. 133 3. Use Cases 135 3.1. Upstream DDoS Mitigation by an Upstream Internet Transit Provider 137 This use case describes how an enterprise or a residential customer 138 network may take advantage of a pre-existing relation with its 139 Internet Transit Provider (ITP) in order to mitigate a DDoS attack 140 targeting its network. 142 To improve the clarity of our purpose, the targeted network will be 143 designated as enterprise network, but the same scenario applies to 144 any downstream network, including residential network and cloud 145 hosting network. 147 As the ITP provides connectivity to the enterprise network, it is 148 already on the path of the inbound and outbound traffic of the 149 enterprise network and well aware of the networking parameters 150 associated to the enterprise network WAN connectivity. This eases 151 both the configuration and the instantiation of a DDoS Mitigation 152 Service. 154 This section considers two kind of DDoS Mitigation Service between an 155 enterprise network and an ITP: 157 o The upstream ITP may instantiate a DDoS Mitigation System (DMS) 158 upon receiving a request from the enterprise network. This 159 typically corresponds to the case when the enterprise network is 160 under attack. 162 o On the other hand, the ITP may identify an enterprise network as 163 the source of an attack and send a mitigation request to the 164 enterprise DMS to mitigate this at the source. 166 The two scenarios, thought different, have similar interactions 167 between the DOTS client and server. For the sake of simplicity, only 168 the first scenario will be detailed in this section. Nevertheless, 169 the second scenario is also in scope of DOTS. 171 In the first scenario, as depicted in Figure 1, an enterprise network 172 with self-hosted Internet-facing properties such as Web servers, 173 authoritative DNS servers, and VoIP servers has a DMS deployed to 174 protect those servers and applications from DDoS attacks. In 175 addition to on-premise DDoS defense capability, the enterprise has 176 contracted with its ITP for DDoS Mitigation Services which threaten 177 to overwhelm their WAN link(s) bandwidth. 179 +------------------+ +------------------+ 180 | Enterprise | | Upstream | 181 | Network | | Internet Transit | 182 | | | Provider | 183 | +--------+ | | DDoS Attack 184 | | DDoS | | <================================= 185 | | Target | | <================================= 186 | +--------+ | | +------------+ | 187 | | +-------->| DDoS | | 188 | | | |S | Mitigation | | 189 | | | | | System | | 190 | | | | +------------+ | 191 | | | | | 192 | | | | | 193 | | | | | 194 | +------------+ | | | | 195 | | DDoS |<---+ | | 196 | | Mitigation |C | | | 197 | | System | | | | 198 | +------------+ | | | 199 +------------------+ +------------------+ 201 * C is for DOTS client functionality 202 * S is for DOTS server functionality 204 Figure 1: Upstream Internet Transit Provider DDoS Mitigation 206 The enterprise DMS is configured such that if the incoming Internet 207 traffic volume exceeds 50% of the provisioned upstream Internet WAN 208 link capacity, the DMS will request DDoS mitigation assistance from 209 the upstream transit provider. More sophisticated detection means 210 may be considered. 212 The requests to trigger, manage, and finalize a DDoS Mitigation 213 between the enterprise DMS and the ITP is performed using DOTS. The 214 enterprise DMS implements a DOTS client while the ITP implements a 215 DOTS server which is integrated with their DMS in this example. 217 When the enterprise DMS locally detects an inbound DDoS attack 218 targeting its resources (e.g., servers, hosts, or applications), it 219 immediately begins a DDoS Mitigation. 221 During the course of the attack, the inbound traffic volume to the 222 enterprise network exceeds the 50% threshold and the enterprise DMS 223 escalates the DDoS mitigation. The enterprise DMS DOTS client 224 signals to the DOTS server on the upstream ITP to initiate DDoS 225 Mitigation. The DOTS server replies to the DOTS client that it can 226 serve this request, and mitigation is initiated on the ITP network by 227 the ITP DMS. 229 Over the course of the attack, the DOTS server of the ITP 230 periodically informs the DOTS client on the enterprise DMS mitigation 231 status, statistics related to DDoS attack traffic mitigation, and 232 related information. Once the DDoS attack has ended, or decreased to 233 the certain level that the enterprise DMS can handle by itself, the 234 DOTS server signals the enterprise DMS DOTS client that the attack 235 has subsided. 237 The DOTS client on the enterprise DMS then requests the ITP to 238 terminate the DDoS Mitigation. The DOTS server on the ITP receives 239 this request and once the mitigation has ended, confirms the end of 240 upstream DDoS Mitigation to the enterprise DMS DOTS client. 242 The following is an overview of the DOTS communication model for this 243 use-case: 245 o (a) A DDoS attack is initiated against resources of a network 246 organization (here, the enterprise) which has deployed a DOTS- 247 capable DMS - typically a DOTS client. 249 o (b) The enterprise DMS detects, classifies, and begins the DDoS 250 Mitigation. 252 o (c) The enterprise DMS determines that its capacity and/or 253 capability to mitigate the DDoS attack is insufficient, and sends 254 via its DOTS client a DOTS DDoS Mitigation request to one or more 255 DOTS servers residing on the upstream ITP. 257 o (d) The DOTS server which receives the DOTS Mitigation request 258 determines that it has been configured to honor requests from the 259 requesting DOTS client, and honors its DDoS Mitigation by 260 orchestrating its DMS. 262 o (e) While the DDoS Mitigation is active, the DOTS server regularly 263 transmits DOTS DDoS Mitigation status updates to the DOTS client. 265 o (f) Informed by the DOTS server status update that the attack has 266 ended or subsided, the DOTS client transmits a DOTS DDoS 267 Mitigation termination request to the DOTS server. 269 o (g) The DOTS server terminates DDoS Mitigation, and sends the 270 notification to the DOTS client. 272 Note that communications between the enterprise DOTS client and the 273 upstream ITP DOTS server may take place in-band within the main 274 Internet WAN link between the enterprise and the ITP; out-of-band via 275 a separate, dedicated wireline network link utilized solely for DOTS 276 signaling; or out-of-band via some other form of network connectivity 277 such as a third-party wireless 4G network connectivity. 279 Note also that a DOTS client that sends a DOTS Mitigation request may 280 be also triggered by a network admin that manually confirms the 281 request to the upstream ITP, in which case the request may be sent 282 from an application such as a web browser or a dedicated mobile 283 application. 285 Note also that when the enterprise is multihomed and connected to 286 multiple upstream ITPs, each ITP is only able to provide a DDoS 287 Mitigation Service for the traffic it transits. As a result, the 288 enterprise network may require to coordinate the various DDoS 289 Mitigation Services associated to each link. More multi-homing 290 considerations are discussed in [I-D.ietf-dots-multihoming]. 292 3.2. DDoS Mitigation by a Third Party DDoS Mitigation Service Provider 294 This use case differs from the previous use case described in 295 Section 3.1 in that the DDoS Mitigation Service is not provided by an 296 upstream ITP. In other words, as represented in Figure 2, the 297 traffic is not forwarded through the DDoS Mitigation Service Provider 298 by default. In order to steer the traffic to the DDoS Mitigation 299 Service Provider, some network configuration changes are required. 300 As such, this use case is likely to match large enterprises or large 301 data centers, but not exclusively. 303 Another typical scenario for this use case is the relation between 304 DDoS Mitigation Service Providers forming an overlay of DMS. When a 305 DDoS Mitigation Service Provider mitigating a DDoS attack reaches it 306 resources capacities, it may chose to delegate the DDoS Mitigation to 307 another DDoS Mitigation Service Provider. 309 +------------------+ +------------------+ 310 | Enterprise | | Upstream | 311 | Network | | Internet Transit | 312 | | | Provider | 313 | +--------+ | | DDoS Attack 314 | | DDoS | | <================================= 315 | | Target | | <================================= 316 | +--------+ | | | 317 | | | | 318 | | +------------------+ 319 | | 320 | | +------------------+ 321 | | | DDoS Mitigation | 322 | | | Service Provider | 323 | | | | 324 | +------------+ | | +------------+ | 325 | | DDoS |<------------>| DDoS | | 326 | | Mitigation |C | | S| Mitigation | | 327 | | System | | | | System | | 328 | +------------+ | | +------------+ | 329 +------------------+ +------------------+ 331 * C is for DOTS client functionality 332 * S is for DOTS server functionality 334 Figure 2: DDoS Mitigation between an Enterprise Network and Third 335 Party DDoS Mitigation Service Provider 337 In this scenario, an enterprise network has entered into a pre- 338 arranged DDoS mitigation assistance agreement with one or more other 339 DDoS Mitigation Service Providers in order to ensure that sufficient 340 DDoS mitigation capacity and/or capabilities may be activated in the 341 event that a given DDoS attack threatens to overwhelm the ability of 342 the enterprise's or any other given DMS to mitigate the attack on its 343 own. 345 The pre-arrangement typically includes the agreement on the 346 mechanisms used to redirect the traffic to the DDoS Mitigation 347 Service Provider, as well as the mechanism to re-inject the traffic 348 back to the Enterprise Network. Redirection to the DDoS Mitigation 349 Service Provider typically involves BGP prefix announcement or DNS 350 redirection, while re-injection of the scrubbed traffic to the 351 enterprise network may be performed via tunneling mechanisms (e.g., 352 GRE). These exact mechanisms used for traffic steering are out of 353 scope. 355 In some cases the communication between the enterprise DOTS client 356 and the DOTS server of the DDoS Mitigation Service Provider may go 357 through the ITP carrying the DDoS attack, which would affect the 358 communication. On the other hand, the communication between the DOTS 359 client and DOTS server may take a path that is not undergoing a DDoS 360 attack. 362 +------------------+ +------------------+ 363 | Enterprise | | Upstream | 364 | Network | | Internet Transit | 365 | | | Provider | 366 | +--------+ | | DDoS Attack 367 | | DDoS | |<----------------+ | ++==== 368 | | Target | | Mitigated | | || ++= 369 | +--------+ | | | | || || 370 | | | | | || || 371 | | +--------|---------+ || || 372 | | | || || 373 | | +--------|---------+ || || 374 | | | DDoS Mitigation | || || 375 | | | Service Provider | || || 376 | | | | | || || 377 | +------------+ | | +------------+ | || || 378 | | DDoS |<------------>| DDoS | | || || 379 | | mitigation |C | |S | mitigation |<===++ || 380 | | system | | | | system |<======++ 381 | +------------+ | | +------------+ | 382 +------------------+ +------------------+ 384 * C is for DOTS client functionality 385 * S is for DOTS server functionality 387 Figure 3: Redirection to a DDoS Mitigation Service Provider 389 When the enterprise network is under attack or at least is reaching 390 its capacity or ability to mitigate a given DDoS attack traffic, the 391 DOTS client sends a DOTS request to the DDoS Mitigation Service 392 Provider to initiate network traffic diversion - as represented in 393 Figure 3 - and DDoS mitigation activities. Ongoing attack and 394 mitigation status messages may be passed between the enterprise 395 network and the DDoS Mitigation Service Provider using DOTS. If the 396 DDoS attack has stopped or the severity of the attack has subsided, 397 the DOTS client can request the DDoS Mitigation Service Provider to 398 stop the DDoS Mitigation. 400 3.3. DDoS Orchestration 402 In this use case, one or more DDoS telemetry systems or monitoring 403 devices monitor a network - typically an ISP network, an enterprise 404 network, or a data center. Upon detection of a DDoS attack, these 405 DDoS telemetry systems alert an orchestrator in charge of 406 coordinating the various DMS's within the domain. The DDoS telemetry 407 systems may be configured to provide required information, such as a 408 preliminary analysis of the observation to the orchestrator. 410 The orchestrator analyses the various information it receives from 411 DDoS telemetry system, and initiates one or multiple DDoS mitigation 412 strategies. For example, the orchestrator could select the DDoS 413 mitigation system in the enterprise network or one provided by the 414 ITP. 416 DDoS Mitigation System selection and DDoS Mitigation techniques may 417 depends on the type of the DDoS attack. In some case, a manual 418 confirmation or selection may also be required to choose a proposed 419 strategy to initiate a DDoS Mitigation. The DDoS Mitigation may 420 consist of multiple steps such as configuring the network, or 421 updating already instantiated DDoS mitigation functions. Eventually, 422 the coordination of the mitigation may involve external DDoS 423 mitigation resources such as a transit provider or a Third Party DDoS 424 Mitigation Service Provider. 426 The communication used to trigger a DDoS Mitigation between the DDoS 427 telemetry and monitoring systems and the orchestrator is performed 428 using DOTS. The DDoS telemetry system implements a DOTS client while 429 the orchestrator implements a DOTS server. 431 The communication between a network administrator and the 432 orchestrator is also performed using DOTS. The network administrator 433 uses a web interface which interacts with a DOTS client, while the 434 orchestrator implements a DOTS server. 436 The communication between the orchestrator and the DDoS Mitigation 437 Systems is performed using DOTS. The orchestrator implements a DOTS 438 client while the DDoS Mitigation Systems implement a DOTS server. 440 The configuration aspects of each DDoS Mitigation System, as well as 441 the instantiations of DDoS mitigation functions or network 442 configuration is not part of DOTS. Similarly, the discovery of 443 available DDoS mitigation functions is not part of DOTS; and as such 444 is out of scope. 446 +----------+ 447 | network |C (Enterprise Network) 448 | adminis |<-+ 449 | trator | | 450 +----------+ | 451 | 452 +----------+ | S+--------------+ +-----------+ 453 |telemetry/| +->| |C S| DDoS |+ 454 |monitoring|<--->| Orchestrator |<--->| mitigation|| 455 |systems |C S| |<-+ | systems || 456 +----------+ +--------------+C | +-----------+| 457 | +----------+ 458 -----------------------------------|----------------- 459 | 460 | 461 (Internet Transit Provider) | 462 | +-----------+ 463 | S| DDoS |+ 464 +->| mitigation|| 465 | systems || 466 +-----------+| 467 * C is for DOTS client functionality +----------+ 468 * S is for DOTS server functionality 470 Figure 4: DDoS Orchestration 472 The DDoS telemetry systems monitor various network traffic and 473 perform some measurement tasks. 475 These systems are configured so that when an event or some 476 measurement indicators reach a predefined level their associated DOTS 477 client sends a DOTS mitigation request to the orchestrator DOTS 478 server. The DOTS mitigation request may be associated with some 479 optional mitigation hints to let the orchestrator know what has 480 triggered the request. 482 Upon receipt of the DOTS mitigation request from the DDoS telemetry 483 system, the orchestrator DOTS server responds with an acknowledgment, 484 to avoid retransmission of the request for mitigation. The 485 orchestrator may begin collecting additional fine-grained and 486 specific information from various DDoS telemetry systems in order to 487 correlate the measurements and provide an analysis of the event. 488 Eventually, the orchestrator may ask for additional information from 489 the DDoS telemetry system; however, the collection of this 490 information is out of scope. 492 The orchestrator may be configured to start a DDoS Mitigation upon 493 approval from a network administrator. The analysis from the 494 orchestrator is reported to the network administrator via a web 495 interface. If the network administrator decides to start the 496 mitigation, the network administrator triggers the DDoS mitigation 497 request using the web interface of a DOTS client communicating to the 498 orchestrator DOTS server. This request is expected to be associated 499 with a context that provides sufficient information to the 500 orchestrator DOTS server to infer the DDoS Mitigation to elaborate 501 and coordinate. 503 Upon receiving a request to mitigate a DDoS attack performed over a 504 target, the orchestrator may evaluate the volumetry of the attack as 505 well as the value that the target represents. The orchestrator may 506 select the DDoS Mitigation Service Provider based on the attack 507 severity. It may also coordinate the DDoS Mitigation performed by 508 the DDoS Mitigation Service Provider with some other tasks such as 509 for example, moving the target to another network so new sessions 510 will not be impacted. The orchestrator requests a DDoS Mitigation to 511 the selected DDoS mitigation systems via its DOTS client, as 512 described in Section 3.1. 514 The orchestrator DOTS client is notified that the DDoS Mitigation is 515 effective by the selected DDoS mitigation systems. The orchestrator 516 DOTS servers returns back this information to the network 517 administrator. 519 Similarly, when the DDoS attack has stopped, the orchestrator DOTS 520 client are being notified and the orchestrator's DOTS servers 521 indicate to the DDoS telemetry systems as well as to the network 522 administrator the end of the DDoS Mitigation. 524 In addition to the above DDoS Orchestration, the selected DDoS 525 mitigation system can return back a mitigation request to the 526 orchestrator as an offloading. For example, when the DDoS attack 527 becomes severe and the DDoS mitigation system's utilization rate 528 reaches its maximum capacity, the DDoS mitigation system can send 529 mitigation requests with additional hints such as its blocked traffic 530 information to the orchestrator. Then the orchestrator can take 531 further actions like requesting forwarding nodes such as routers to 532 filter the traffic. In this case, the DDoS mitigation system 533 implements a DOTS client while the orchestrator implements a DOTS 534 server. Similar to other DOTS use cases, the offloading scenario 535 assumes that some validation checks are followed by the DMS, the 536 orchestrator, or both (e.g., avoid exhausting the resources of the 537 forwarding nodes or disrupting the service). These validation checks 538 are part of the mitigation, and are therefore out of the scope of the 539 document. 541 4. Security Considerations 543 The document does not describe any protocol. 545 DOTS is at risk from three primary attacks: DOTS agent impersonation, 546 traffic injection, and signaling blocking. 548 Impersonation and traffic injection mitigation can be mitigated 549 through current secure communications best practices. Preconfigured 550 mitigation steps to take on the loss of keepalive traffic can 551 partially mitigate signal blocking, but in general it is impossible 552 to comprehensively defend against an attacker that can selectively 553 block any or all traffic 555 Additional details of DOTS security requirements can be found in 556 [RFC8612]. 558 Service disruption may be experienced if inadequate mitigation 559 actions are applied. These considerations are out of the scope of 560 DOTS. 562 5. IANA Considerations 564 No IANA considerations exist for this document. 566 6. Acknowledgments 568 The authors would like to thank among others Tirumaleswar Reddy; 569 Andrew Mortensen; Mohamed Boucadair; Artyom Gavrichenkov; Jon 570 Shallow, Yuuhei Hayashi, the DOTS WG chairs, Roman Danyliw and Tobias 571 Gondrom as well as the Security AD Benjamin Kaduk for their valuable 572 feedback. 574 We also would like to thank Stephan Fouant that was part of the 575 initial co-authors of the documents. 577 7. Informative References 579 [I-D.ietf-dots-multihoming] 580 Boucadair, M., K, R., and W. Pan, "Multi-homing Deployment 581 Considerations for Distributed-Denial-of-Service Open 582 Threat Signaling (DOTS)", draft-ietf-dots-multihoming-02 583 (work in progress), July 2019. 585 [RFC8612] Mortensen, A., Reddy, T., and R. Moskowitz, "DDoS Open 586 Threat Signaling (DOTS) Requirements", RFC 8612, 587 DOI 10.17487/RFC8612, May 2019, 588 . 590 Authors' Addresses 592 Roland Dobbins 593 Arbor Networks 594 Singapore 596 EMail: rdobbins@arbor.net 598 Daniel Migault 599 Ericsson 600 8275 Trans Canada Route 601 Saint Laurent, QC 4S 0B6 602 Canada 604 EMail: daniel.migault@ericsson.com 606 Robert Moskowitz 607 HTT Consulting 608 Oak Park, MI 48237 609 USA 611 EMail: rgm@labs.htt-consult.com 613 Nik Teague 614 Iron Mountain Data Centers 615 UK 617 EMail: nteague@ironmountain.co.uk 619 Liang Xia 620 Huawei 621 No. 101, Software Avenue, Yuhuatai District 622 Nanjing 623 China 625 EMail: Frank.xialiang@huawei.com 626 Kaname Nishizuka 627 NTT Communications 628 GranPark 16F 3-4-1 Shibaura, Minato-ku 629 Tokyo 108-8118 630 Japan 632 EMail: kaname@nttv6.jp