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Bierman 8 YumaWorks 9 September 25, 2020 11 Comparison of NMDA datastores 12 draft-ietf-netmod-nmda-diff-07 14 Abstract 16 This document defines an RPC operation to compare management 17 datastores that comply with the NMDA architecture. 19 Status of This Memo 21 This Internet-Draft is submitted in full conformance with the 22 provisions of BCP 78 and BCP 79. 24 Internet-Drafts are working documents of the Internet Engineering 25 Task Force (IETF). Note that other groups may also distribute 26 working documents as Internet-Drafts. The list of current Internet- 27 Drafts is at https://datatracker.ietf.org/drafts/current/. 29 Internet-Drafts are draft documents valid for a maximum of six months 30 and may be updated, replaced, or obsoleted by other documents at any 31 time. It is inappropriate to use Internet-Drafts as reference 32 material or to cite them other than as "work in progress." 34 This Internet-Draft will expire on March 29, 2021. 36 Copyright Notice 38 Copyright (c) 2020 IETF Trust and the persons identified as the 39 document authors. All rights reserved. 41 This document is subject to BCP 78 and the IETF Trust's Legal 42 Provisions Relating to IETF Documents 43 (https://trustee.ietf.org/license-info) in effect on the date of 44 publication of this document. Please review these documents 45 carefully, as they describe your rights and restrictions with respect 46 to this document. Code Components extracted from this document must 47 include Simplified BSD License text as described in Section 4.e of 48 the Trust Legal Provisions and are provided without warranty as 49 described in the Simplified BSD License. 51 Table of Contents 53 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 54 2. Key Words . . . . . . . . . . . . . . . . . . . . . . . . . . 3 55 3. Definitions and Acronyms . . . . . . . . . . . . . . . . . . 3 56 4. Data Model Overview . . . . . . . . . . . . . . . . . . . . . 4 57 5. YANG Data Model . . . . . . . . . . . . . . . . . . . . . . . 6 58 6. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 59 7. Performance Considerations . . . . . . . . . . . . . . . . . 14 60 8. Possible Future Extensions . . . . . . . . . . . . . . . . . 15 61 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 62 9.1. Updates to the IETF XML Registry . . . . . . . . . . . . 15 63 9.2. Updates to the YANG Module Names Registry . . . . . . . . 16 64 10. Security Considerations . . . . . . . . . . . . . . . . . . . 16 65 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 17 66 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 17 67 12.1. Normative References . . . . . . . . . . . . . . . . . . 17 68 12.2. Informative References . . . . . . . . . . . . . . . . . 18 69 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 71 1. Introduction 73 The revised Network Management Datastore Architecture (NMDA) 74 [RFC8342] introduces a set of new datastores that each hold YANG- 75 defined data [RFC7950] and represent a different "viewpoint" on the 76 data that is maintained by a server. New YANG datastores that are 77 introduced include , which contains validated configuration 78 data that a client application intends to be in effect, and 79 , which contains at least conceptually operational state 80 data (such as statistics) as well as configuration data that is 81 actually in effect. 83 NMDA introduces in effect a concept of "lifecycle" for management 84 data, allowing to clearly distinguish between data that is part of a 85 configuration that was supplied by a user, configuration data that 86 has actually been successfully applied and that is part of the 87 operational state, and overall operational state that includes both 88 applied configuration data as well as status and statistics. 90 As a result, data from the same management model can be reflected in 91 multiple datastores. Clients need to specify the target datastore to 92 be specific about which viewpoint of the data they want to access. 93 This way, an application can differentiate whether they are (for 94 example) interested in the configuration that has been applied and is 95 actually in effect, or in the configuration that was supplied by a 96 client and that is supposed to be in effect. 98 Due to the fact that data can propagate from one datastore to 99 another, it is possibly for differences between datastores to occur. 100 Some of this is entirely expected, as there may be a time lag between 101 when a configuration is given to the device and reflected in 102 , until when it actually takes effect and is reflected in 103 . However, there may be cases when a configuration item 104 that was to be applied may not actually take effect at all or needs 105 an unusually long time to do so. This can be the case due to certain 106 conditions not being met, resource dependencies not being resolved, 107 or even implementation errors in corner conditions. 109 When configuration that is in effect is different from configuration 110 that was applied, many issues can result. It becomes more difficult 111 to operate the network properly due to limited visibility of actual 112 status which makes it more difficult to analyze and understand what 113 is going on in the network. Services may be negatively affected (for 114 example, breaking a service instance resulting in service is not 115 properly delivered to a customer) and network resources be 116 misallocated. 118 Applications can potentially analyze any differences between two 119 datastores by retrieving the contents from both datastores and 120 comparing them. However, in many cases this will be at the same time 121 costly and extremely wasteful. 123 This document introduces a YANG data model which defines RPCs, 124 intended to be used in conjunction with NETCONF [RFC6241] or RESTCONF 125 [RFC8040], that allow a client to request a server to compare two 126 NMDA datastores and report any differences. 128 2. Key Words 130 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 131 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 132 "OPTIONAL" in this document are to be interpreted as described in BCP 133 14 [RFC2119] [RFC8174] when, and only when, they appear in all 134 capitals, as shown here. 136 3. Definitions and Acronyms 138 NMDA: Network Management Datastore Architecture 140 RPC: Remote Procedure Call 142 4. Data Model Overview 144 At the core of the solution is a new management operation, , 145 that allows to compare two datastores for the same data. The 146 operation checks whether there are any differences in values or in 147 data nodes that are contained in either datastore, and returns any 148 differences as output. The output is returned in the format 149 specified in YANG-Patch [RFC8072]. 151 The YANG data model defines the operation as a new RPC. 152 The operation takes the following input parameters: 154 o source: The source identifies the datastore that will serve as 155 reference for the comparison, for example . 157 o target: The target identifies the datastore to compare against the 158 source. 160 o filter-spec: This is a choice between different filter constructs 161 to identify the portions of the datastore to be retrieved. It 162 acts as a node selector that specifies which data nodes are within 163 the scope of the comparison and which nodes are outside the scope. 164 This allows a comparison operation to be applied only to a 165 specific portion of the datastore that is of interest, such as a 166 particular subtree. (The filter dow not contain expressions that 167 would match values data nodes, as this is not required by most use 168 cases and would complicate the scheme, from implementation to 169 dealing with race conditions.) 171 o all: When set, this parameter indicates that all differences 172 should be included, including differences pertaining to schema 173 nodes that exist in only one of the datastores. When this 174 parameter is not included, a prefiltering step is automatically 175 applied to exclude data from the comparison that does not pertain 176 to both datastores: if the same schema node is not present in both 177 datastores, then all instances of that schema node and all its 178 descendants are excluded from the comparison. This allows client 179 applications to focus on the differences that constitute true 180 mismatches of instance data without needing to specify more 181 complex filter constructs. 183 o exclude-origin: When set, this parameter indicates that origin 184 metadata should not not be included as part of RPC output. When 185 this parameter is omitted, origin metadata in comparisons that 186 involve is by default included. 188 The operation provides the following output parameter: 190 o differences: This parameter contains the list of differences. 191 Those differences are encoded per YANG-Patch data model defined in 192 RFC8072. When a datastore node in the source of the comparison is 193 not present in the target of the comparison, this can be indicated 194 either as a "delete" or as a "remove" in the patch as there is no 195 differentiation between those operations for the purposes of the 196 comparison. The YANG-Patch data model is augmented to indicate 197 the value of source datastore nodes in addition to the patch 198 itself that would need to be applied to the source to produce the 199 target. When the target datastore is , "origin" 200 metadata is included as part of the patch. Including origin 201 metadata can help in some cases explain the cause of a difference, 202 for example when a data node is part of but the origin 203 of the same data node in is reported as "system". 205 The data model is defined in the ietf-nmda-compare YANG module. Its 206 structure is shown in the following figure. The notation syntax 207 follows [RFC8340]. 209 module: ietf-nmda-compare 210 rpcs: 211 +---x compare 212 +---w input 213 | +---w source identityref 214 | +---w target identityref 215 | +---w all? empty 216 | +---w exclude-origin? empty 217 | +---w (filter-spec)? 218 | +--:(subtree-filter) 219 | | +---w subtree-filter? 220 | +--:(xpath-filter) 221 | +---w xpath-filter? yang:xpath1.0 {nc:xpath}? 222 +--ro output 223 +--ro (compare-response)? 224 +--:(no-matches) 225 | +--ro no-matches? empty 226 +--:(differences) 227 +--ro differences 228 +--ro yang-patch 229 +--ro patch-id string 230 +--ro comment? string 231 +--ro edit* [edit-id] 232 +--ro edit-id string 233 +--ro operation enumeration 234 +--ro target target-resource-offset 235 +--ro point? target-resource-offset 236 +--ro where? enumeration 237 +--ro value? 238 +--ro source-value? 240 Structure of ietf-nmda-compare 242 5. YANG Data Model 244 file "ietf-nmda-compare@2020-09-18.yang" 245 module ietf-nmda-compare { 247 yang-version 1.1; 248 namespace "urn:ietf:params:xml:ns:yang:ietf-nmda-compare"; 250 prefix cmp; 252 import ietf-yang-types { 253 prefix yang; 254 reference "RFC 6991: Common YANG Data Types"; 255 } 256 import ietf-datastores { 257 prefix ds; 258 reference "RFC 8342: Network Management Datastore 259 Architecture (NMDA)"; 260 } 261 import ietf-yang-patch { 262 prefix ypatch; 263 reference "RFC 8072: YANG Patch Media Type"; 264 } 265 import ietf-netconf { 266 prefix nc; 267 reference "RFC6241: Network Configuration Protocol (NETCONF)"; 268 } 270 organization "IETF"; 271 contact 272 "WG Web: 273 WG List: 275 Author: Alexander Clemm 276 278 Author: Yingzhen Qu 279 281 Author: Jeff Tantsura 282 284 Author: Andy Bierman 285 "; 287 description 288 "The YANG data model defines a new operation, , that 289 can be used to compare NMDA datastores. 291 The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL 292 NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED', 293 'MAY', and 'OPTIONAL' in this document are to be interpreted as 294 described in BCP 14 (RFC 2119) (RFC 8174) when, and only when, 295 they appear in all capitals, as shown here. 297 Copyright (c) 2020 IETF Trust and the persons identified as 298 authors of the code. All rights reserved. 300 Redistribution and use in source and binary forms, with or 301 without modification, is permitted pursuant to, and subject to 302 the license terms contained in, the Simplified BSD License set 303 forth in Section 4.c of the IETF Trust's Legal Provisions 304 Relating to IETF Documents 305 (https://trustee.ietf.org/license-info). 307 This version of this YANG module is part of RFC XXXX; see the 308 RFC itself for full legal notices."; 310 revision 2020-09-18 { 311 description 312 "Initial revision"; 313 reference 314 "RFC XXXX: Comparison of NMDA datastores"; 315 } 317 /* RPC */ 318 rpc compare { 319 description 320 "NMDA compare operation."; 321 input { 322 leaf source { 323 type identityref { 324 base ds:datastore; 325 } 326 mandatory true; 327 description 328 "The source datastore to be compared."; 329 } 330 leaf target { 331 type identityref { 332 base ds:datastore; 333 } 334 mandatory true; 335 description 336 "The target datastore to be compared."; 337 } 338 leaf all { 339 type empty; 340 description 341 "When this leaf is provided, all data nodes are compared, 342 whether their schema node pertains to both datastores or 343 not. When this leaf is omitted, a prefiltering step is 344 automatically applied that excludes data nodes from the 345 comparison that can occur in only one datastore but not 346 the other. Specifically, if one of the datastores 347 (source or target) contains only configuration data and 348 the other datastore is , data nodes for 349 which config is false are excluded from the comparison."; 350 } 351 leaf exclude-origin { 352 type empty; 353 description 354 "When this leaf is provided, origin metadata is not 355 included as part of RPC output. When this leaf is 356 omitted, origin metadata in comparisons that involve 357 is by default included."; 358 } 359 choice filter-spec { 360 description 361 "Identifies the portions of the datastores to be 362 compared."; 363 anydata subtree-filter { 364 description 365 "This parameter identifies the portions of the 366 target datastore to retrieve."; 367 reference "RFC 6241, Section 6."; 368 } 369 leaf xpath-filter { 370 if-feature nc:xpath; 371 type yang:xpath1.0; 372 description 373 "This parameter contains an XPath expression 374 identifying the portions of the target 375 datastore to retrieve."; 376 reference "RFC 6991: Common YANG Data Types"; 377 } 378 } 379 } 380 output { 381 choice compare-response { 382 description 383 "Comparison results."; 384 leaf no-matches { 385 type empty; 386 description 387 "This leaf indicates that the filter did not match 388 anything and nothing was compared."; 389 } 390 container differences { 391 description 392 "The list of differences, encoded per RFC8072 with an 393 augmentation to include source values where applicable. 394 When a datastore node in the source is not present in 395 the target, this can be indicated either as a 'delete' 396 or as a 'remove' as there is no difference between 397 them for the purposes of the comparison."; 398 uses ypatch:yang-patch { 399 augment "yang-patch/edit" { 400 description 401 "Provide the value of the source of the patch, 402 respectively of the comparison, in addition to 403 the target value, where applicable."; 404 anydata source-value { 405 when "../operation = 'delete'" 406 + "or ../operation = 'merge'" 407 + "or ../operation = 'move'" 408 + "or ../operation = 'replace'" 409 + "or ../operation = 'remove'"; 410 description 411 "The anydata 'value' is only used for 'delete', 412 'move', 'merge', 'replace', and 'remove' 413 operations."; 414 } 415 reference "RFC 8072: YANG Patch Media Type"; 416 } 417 } 418 } 419 } 420 } 421 } 422 } 423 425 6. Example 427 The following example compares the difference between 428 and for a subtree under "interfaces". The subtree 429 contains a subset of objects that are defined in a YANG data model 430 for the management of interfaces defined in [RFC8343]. The excerpt 431 of the data model whose instantiation is basis of the comparison is 432 as follows: 434 container interfaces { 435 description 436 "Interface parameters."; 437 list interface { 438 key "name"; 439 leaf name { 440 type string; 441 description 442 "The name of the interface". 443 } 444 leaf description { 445 type string; 446 description 447 "A textual description of the interface."; 448 } 449 leaf enabled { 450 type boolean; 451 default "true"; 452 description 453 "This leaf contains the configured, desired state of the 454 interface.";" 455 } 456 } 457 } 459 The contents of and datastores: 461 //INTENDED 462 463 464 eth0 465 false 466 ip interface 467 468 470 //OPERATIONAL 471 474 475 eth0 476 true 478 479 480 does not contain object "description" that is contained 481 in . Another object, "enabled", has differences in values, 482 being "true" in and "false" in . A third 483 object, "name", is the same in both cases. The origin of the objects 484 in is "learned", which may help explain the 485 discrepancies. 487 RPC request to compare (source of the comparison) with 488 (target of the comparison): 490 492 494 ds:operational 495 ds:intended 496 498 /if:interfaces 499 500 501 503 RPC reply, when a difference is detected: 505 508 511 512 interface status 513 514 diff between operational (source) and intended (target) 515 516 517 1 518 replace 519 /ietf-interfaces:interface=eth0/enabled 520 521 false 522 523 524 true 525 526 527 528 2 529 create 530 /ietf-interfaces:interface=eth0/description 531 532 ip interface 533 534 535 536 537 539 The same request in RESTCONF (using JSON format): 541 POST /restconf/operations/ietf-nmda-compare:compare HTTP/1.1 542 Host: example.com 543 Content-Type: application/yang-data+json 544 Accept: application/yang-d 545 { "ietf-nmda-compare:input" { 546 "source" : "ietf-datastores:operational" 547 "target" : "ietf-datastores:intended" 548 "xpath-filter" : \ 549 "/ietf-interfaces:interfaces" 550 } 551 } 552 The same response in RESTCONF (using JSON format): 554 HTTP/1.1 200 OK 555 Date: Thu, 26 Jan 2019 20:56:30 GMT 556 Server: example-server 557 Content-Type: application/yang-d 558 { "ietf-nmda-compare:output" : { 559 "differences" : { 560 "ietf-yang-patch:yang-patch" : { 561 "patch-id" : "interface status", 562 "comment" : "diff between intended (source) and operational", 563 "edit" : [ 564 { 565 "edit-id" : "1", 566 "operation" : "replace", 567 "target" : "/ietf-interfaces:interface=eth0/enabled", 568 "value" : { 569 "ietf-interfaces:interface/enabled" : "false" 570 }, 571 "source-value" : { 572 "ietf-interfaces:interface/enabled" : "true", 573 "@ietf-interfaces:interface/enabled" : { 574 "ietf-origin:origin" : "ietf-origin:learned" 575 } 576 } 577 }, 578 { 579 "edit-id" : "2", 580 "operation" : "create", 581 "target" : "/ietf-interfaces:interface=eth0/description", 582 "value" : { 583 "ietf-interface:interface/description" : "ip interface" 584 } 585 } 586 ] 587 } 588 } 589 } 590 } 592 7. Performance Considerations 594 The compare operation can be computationally expensive. While 595 responsible client applications are expected to use the operation 596 responsibly and sparingly only when warranted, implementations need 597 to be aware of the fact that excessive invocation of this operation 598 will burden system resources and need to ensure that system 599 performance will not be adversely impacted. One possibility for an 600 implementation to mitigate against such a possibility is to limit the 601 number of requests that is served to a client, or to any number of 602 clients, in any one time interval, rejecting requests made at a 603 higher frequency than the implementation can reasonably sustain. 605 8. Possible Future Extensions 607 It is conceivable to extend the compare operation with a number of 608 possible additional features in the future. 610 Specifically, it is possible to define an extension with an optional 611 feature for dampening. This will allow clients to specify a minimum 612 time period for which a difference must persist for it to be 613 reported. This will enable clients to distinguish between 614 differences that are only fleeting from ones that are not and that 615 may represent a real operational issue and inconsistency within the 616 device. 618 For this purpose, an additional input parameter can be added to 619 specify the dampening period. Only differences that pertain for at 620 least the dampening time are reported. A value of 0 or omission of 621 the parameter indicates no dampening. Reporting of differences MAY 622 correspondingly be delayed by the dampening period from the time the 623 request is received. 625 To implement this feature, a server implementation might run a 626 comparison when the RPC is first invoked and temporarily store the 627 result. Subsequently, it could wait until after the end of the 628 dampening period to check whether the same differences are still 629 observed. The differences that still persist are then returned. 631 9. IANA Considerations 633 9.1. Updates to the IETF XML Registry 635 This document registers one URI in the IETF XML registry [RFC3688]. 636 Following the format in [RFC3688], the following registration is 637 requested: 639 URI: urn:ietf:params:xml:ns:yang:ietf-nmda-compare 641 Registrant Contact: The IESG. 643 XML: N/A, the requested URI is an XML namespace. 645 9.2. Updates to the YANG Module Names Registry 647 This document registers a YANG module in the YANG Module Names 648 registry [RFC7950]. Following the format in [RFC7950], the following 649 registration is requested: 651 name: ietf-nmda-compare 653 namespace: urn:ietf:params:xml:ns:yang:ietf-nmda-compare 655 prefix: cmp 657 reference: RFC XXXX 659 10. Security Considerations 661 The YANG module specified in this document defines a schema for data 662 that is designed to be accessed via network management protocols such 663 as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer 664 is the secure transport layer, and the mandatory-to-implement secure 665 transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer 666 is HTTPS, and the mandatory-to-implement secure transport is TLS 667 [RFC8446]. 669 The NETCONF access control model [RFC8341] provides the means to 670 restrict access for particular NETCONF or RESTCONF users to a 671 preconfigured subset of all available NETCONF or RESTCONF protocol 672 operations and content. 674 The RPC operation defined in this YANG module, "compare", may be 675 considered sensitive or vulnerable in some network environments. It 676 is thus important to control access to this operation. This is the 677 sensitivity/vulnerability of RPC operation "compare": 679 Comparing datastores for differences requires a certain amount of 680 processing resources at the server. An attacker could attempt to 681 attack a server by making a high volume of comparison requests. 682 Server implementations can guard against such scenarios in several 683 ways. For one, they can implement the NETCONF access control model 684 in order to require proper authorization for requests to be made. 685 Second, server implementations can limit the number of requests that 686 they serve to a client in any one time interval, rejecting requests 687 made at a higher frequency than the implementation can reasonably 688 sustain. 690 11. Acknowledgments 692 We thank Rob Wilton, Martin Bjorklund, Mahesh Jethanandani, Lou 693 Berger, Kent Watsen, Phil Shafer, Ladislav Lhotka, Tim Carey, and 694 Reshad Rahman for valuable feedback and suggestions. 696 12. References 698 12.1. Normative References 700 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 701 Requirement Levels", BCP 14, RFC 2119, 702 DOI 10.17487/RFC2119, March 1997, 703 . 705 [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, 706 DOI 10.17487/RFC3688, January 2004, 707 . 709 [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., 710 and A. Bierman, Ed., "Network Configuration Protocol 711 (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, 712 . 714 [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure 715 Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, 716 . 718 [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", 719 RFC 6991, DOI 10.17487/RFC6991, July 2013, 720 . 722 [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", 723 RFC 7950, DOI 10.17487/RFC7950, August 2016, 724 . 726 [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF 727 Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, 728 . 730 [RFC8072] Bierman, A., Bjorklund, M., and K. Watsen, "YANG Patch 731 Media Type", RFC 8072, DOI 10.17487/RFC8072, February 732 2017, . 734 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 735 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 736 May 2017, . 738 [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", 739 BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, 740 . 742 [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration 743 Access Control Model", STD 91, RFC 8341, 744 DOI 10.17487/RFC8341, March 2018, 745 . 747 [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., 748 and R. Wilton, "Network Management Datastore Architecture 749 (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, 750 . 752 [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol 753 Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, 754 . 756 12.2. Informative References 758 [RFC8343] Bjorklund, M., "A YANG Data Model for Interface 759 Management", RFC 8343, DOI 10.17487/RFC8343, March 2018, 760 . 762 Authors' Addresses 764 Alexander Clemm 765 Futurewei 766 2330 Central Expressway 767 Santa Clara, CA 95050 768 USA 770 Email: ludwig@clemm.org 772 Yingzhen Qu 773 Futurewei 774 2330 Central Expressway 775 Santa Clara, CA 95050 776 USA 778 Email: yqu@futurewei.com 780 Jeff Tantsura 781 Apstra 783 Email: jefftant.ietf@gmail.com 784 Andy Bierman 785 YumaWorks 787 Email: andy@yumaworks.com