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Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document doesn't use any RFC 2119 keywords, yet seems to have RFC 2119 boilerplate text. -- The document date (February 14, 2020) is 1526 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Unused Reference: 'ZSM003' is defined on line 713, but no explicit reference was found in the text == Outdated reference: A later version (-06) exists of draft-contreras-teas-slice-nbi-00 Summary: 1 error (**), 0 flaws (~~), 4 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group X. Geng 3 Internet-Draft J. Dong 4 Intended status: Informational Huawei Technologies 5 Expires: August 17, 2020 T. Niwa 6 KDDI 7 J. Jin 8 LG U+ 9 February 14, 2020 11 5G End-to-end Network Slice Mapping from the view of Transport Network 12 draft-geng-teas-network-slice-mapping-00 14 Abstract 16 Network Slicing is one of the core featrures in 5G. End-to-end 17 network slicing consists of 3 major types of network segments: Access 18 Network (AN), Mobile Core Network (CN) and Transport Network (TN). 19 This draft describes the procedure of mapping relationship between 5G 20 end-to-end network slice into and transport network slice defined in 21 IETF. This draft also intends to expose some gaps in the existing 22 network management plane and data plane to support inter-domain 23 network slice mapping. Further work may require cooperation between 24 IETF and 3GPP (or other standard organizations). The definition of 25 data model, signaling protocol extension and new encapsulation is out 26 of the scope of this draft. 28 Requirements Language 30 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 31 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 32 document are to be interpreted as described in RFC 2119 [RFC2119]. 34 Status of This Memo 36 This Internet-Draft is submitted in full conformance with the 37 provisions of BCP 78 and BCP 79. 39 Internet-Drafts are working documents of the Internet Engineering 40 Task Force (IETF). Note that other groups may also distribute 41 working documents as Internet-Drafts. The list of current Internet- 42 Drafts is at https://datatracker.ietf.org/drafts/current/. 44 Internet-Drafts are draft documents valid for a maximum of six months 45 and may be updated, replaced, or obsoleted by other documents at any 46 time. It is inappropriate to use Internet-Drafts as reference 47 material or to cite them other than as "work in progress." 48 This Internet-Draft will expire on August 17, 2020. 50 Copyright Notice 52 Copyright (c) 2020 IETF Trust and the persons identified as the 53 document authors. All rights reserved. 55 This document is subject to BCP 78 and the IETF Trust's Legal 56 Provisions Relating to IETF Documents 57 (https://trustee.ietf.org/license-info) in effect on the date of 58 publication of this document. Please review these documents 59 carefully, as they describe your rights and restrictions with respect 60 to this document. Code Components extracted from this document must 61 include Simplified BSD License text as described in Section 4.e of 62 the Trust Legal Provisions and are provided without warranty as 63 described in the Simplified BSD License. 65 Table of Contents 67 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 68 2. Terminologies . . . . . . . . . . . . . . . . . . . . . . . . 3 69 3. Network Slice Mapping Structure . . . . . . . . . . . . . . . 4 70 3.1. Requirements Profile . . . . . . . . . . . . . . . . . . 5 71 3.2. Identifiers . . . . . . . . . . . . . . . . . . . . . . . 6 72 3.3. Relevant functions . . . . . . . . . . . . . . . . . . . 6 73 4. Network Slice Mapping Procedure . . . . . . . . . . . . . . . 7 74 4.1. Network Slice Mapping in Management Plane . . . . . . . . 8 75 4.2. Network Slice Mapping in Control Plane . . . . . . . . . 9 76 4.3. Network Slice Mapping in data plane . . . . . . . . . . . 10 77 4.3.1. Data Plane Mapping Considerations . . . . . . . . . . 10 78 4.3.2. Data Plane Mapping Design . . . . . . . . . . . . . . 10 79 5. Network Slice Mapping Summary . . . . . . . . . . . . . . . . 15 80 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 81 7. Security Considerations . . . . . . . . . . . . . . . . . . . 15 82 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 83 9. Normative References . . . . . . . . . . . . . . . . . . . . 15 84 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 86 1. Introduction 88 Driven by the new applications of 5G, the concept of network slicing 89 is defined to provide a logical network with specific network 90 capabilities and network characteristics. Network slice contains a 91 set of network functions and the required resources(e.g. 92 Computation, storage and network resources).According to [TS28530], a 93 5G end-to-end network slice consists of three major types network 94 segments: Radio Access Network (RAN), Transport Network (TN) and 95 Mobile Core Network (CN). Transport network is supposed to provide 96 the required connectivity between AN and CN, which specific 97 performance commitment. For each end-to-end network slice, the 98 topology and performance requirement on transport network can be very 99 different, which requires transport network to have the capability of 100 supporting multiple different transport network slices. 102 A transport network slice is a virtual (logical) network with a 103 particular network topology and a set of shared or dedicated network 104 resources, which are used to provide the network slice consumer with 105 the required connectivity, appropriate isolation and specific Service 106 Level Agreement (SLA). A transport network slice could span multiple 107 technology (IP, Optical) and multiple administrative domains. 108 Depending on the consumer's requirement, a transport network slice 109 could be isolated from other, often concurrent transport network 110 slices in terms of data plane, control plane and management plane. 111 Transport network slice is being defined and discussed in IETF. 113 The procedure of end-to-end network slice instance creation, network 114 slice subnet instance creation and network slice instance termination 115 in management plane are defined in [TS28531]. The end-to-end network 116 slice allocation is defined in ETSI ZSM003. But there is no 117 specifications about how to map end-to-end network slice in 5G system 118 to transport network slice. This draft describes the procedure of 119 mapping 5G end-to-end network slice into transport network slice in 120 management plane, control plane and user plane. 122 2. Terminologies 124 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 125 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 126 document are to be interpreted as described in [RFC2119]. 128 The following terms are used in this document: 130 NS: Network Slice 132 NSI: Network Slice Instance 134 NSSI: Network Slice Subnet Instance 136 NSSAI: Network Slice Selection Assistance Information 138 S-NSSAI: Single Network Slice Selection Assistance Information 140 AN: Access Network 142 RAN: Radio Access Network 143 TN: Transport Network 145 CN: Mobile Core Network 147 DSCP: Differentiated Services Code Point 149 CSMF: Communication Service Management Function 151 NSMF: Network Slice Management Function 153 NSSMF: Network Slice Subnet Management Function 155 GST: General Slice Template 157 TNSII: Transport Network Slice Interworking Identifier 159 TNSI: Transport Network Slice Identifier 161 PDU: Protocol Data Unit 163 Editor's Note: Terminologies defined in 3GPP, e.g.,Network Slice 164 Subnet Management Function(NSSMF), Network Slice Subnet 165 Instance(NSSI) and Network Slice Selection Assistance 166 Information(NSSAI), is used in the end-to-end network slice mapping, 167 which may not be used necessarily within the transport network. 169 3. Network Slice Mapping Structure 171 The following figure shows the necessary elements for mapping end-to- 172 end network slice into transport network slice. All these network 173 slice elements are classified into three groups: requirements/ 174 capabilities, identifiers and relevant functions. 176 +-----------------+ 177 | CSMF | 178 +--------+--------+ 179 | 180 +--------V--------+ 181 | NSMF | 182 +-----------------+ 183 +----------| NSI Identifier |----------+ 184 | | Service Profile | | 185 | | TN Network- | | 186 | | -Slice Profile | | 187 | +-----------------+ | 188 | | | 189 +------V------+ +----------V----------+ +------V------+ 190 | AN NSSMF | | TN NSSMF | | CN NSSMF | 191 +-------------+ +---------------------+ +-------------+ 192 | AN-NSSI- | | TN-NSSI Identifier | | CN-NSSI- | 193 | -Identifier | | Function Management| | -Identifier | 194 | ... | | ... | | ... | Management 195 +-------------+ +---------------------+ +-------------+ Plane 196 | | | | ----------------- 197 |<----------PDU session (S-NSSAI)---------->| Control 198 | | | | Plane 199 V V V V ----------------- 200 /\ +-----+ +-----+ +-------+ Data 201 /AN\ -----| PE |-----...-----| PE |----| UPF | Plane 202 /____\ +-----+ +-----+ +-------+ 203 |-->TNSII<--|------>TNSI<-------|-->TNSII<--| 205 TNSII: Transport Network Slice Interworking Identifier 206 TNSI: Transport Network Slice Identifier 208 3.1. Requirements Profile 210 In order to satisfy a tenant's request for a network slice with 211 certain characteristics, creating a new network slice or using 212 existing network slice instance is constrained by the customer's 213 requirement and the capability of the network slices. 215 o Service Profile: represents the properties of network slice 216 related requirement that should be supported by the network slice 217 instance in 5G network. Service profile is defined in [TS28541] 218 6.3.3. 220 o TN Network Slice Profile: represents the properties of transport 221 network slice related requirement that should be supported by the 222 transport network slice in a 5G network. Slice Profile is defined 223 in [TS28541] 6.3.4. TN Network slice profile is newly defined in 224 this draft. 226 3.2. Identifiers 228 Network slice related identifiers in management plane, control plane 229 and user(data) plane play an important role in end-to-end network 230 slice mapping. 232 o Single Network Slice Selection Assistance Information(S-NSSAI): 233 end-to-end network slice identifier in control plane, which is 234 defined in [TS23501]; 236 o Network Slice Instance(NSI) Identifier: end-to-end network slice 237 identifier in management plane, which is created in NSMF; NSI is 238 is set of Network Function instances and the required resources 239 (e.g. compute, storage and networking resources) which form a 240 deployed Network Slice, which is defined in [TS23501]; 242 o Transport Network Slice Instance(TN-NSSI) Identifier: transport 243 network slice identifier in management plane, which is created in 244 TN NSSMF; TN-NSSI is newly defined in this draft. 246 o Transport Network Slice Interworking Identifier (TNSII): network 247 slice identifier which is used for mapping end-to-end network 248 slice into transport network slice in user plane. TNSII is newly 249 defined in this draft. 251 o Transport Network Slice Identifier(TNSI): transport network slice 252 identifier in data plane(user plane). TNSI is newly defined in 253 this draft. 255 The relationship between these identifiers are specifies in the 256 following sections. 258 3.3. Relevant functions 260 There are a set of slice relevant functions that are necessary for 261 transport network slice management: 263 o Topology management 265 o QoS management 267 o Resource management 269 o Measurement management 270 o ... 272 Some of these functions are implemented inside the transport network 273 and independent from the end-to-end network slice, e.g., topology 274 management, QoS management, resource management; Some of the 275 functions are related to the end-to-end network slice and should 276 cooperate with other network elements from other domain, e.g., 277 Measurement management. 279 4. Network Slice Mapping Procedure 281 This section provides a general procedure of network slice mapping: 283 +--------------------------------+ 284 | Requirement Matching | 285 +---------------+----------------+ 286 | 287 V 288 +--------------------------------+ 289 | NSI<->NSSI Mapping | 290 +---------------+----------------+ 291 | 292 V 293 +--------------------------------+ 294 | S-NSSAI Selection | 295 +---------------+----------------+ 296 | 297 V 298 +--------------------------------+ 299 | S-NSSAI<->TNSII Mapping | 300 +---------------+----------------+ 301 | 302 V 303 +--------------------------------+ 304 | TNSII<->TNSI Mapping | 305 +--------------------------------+ 307 1. NSMF receives the request from CSMF for allocation of the network 308 slice instance with certain characteristics. 310 2. Based on the service requirement , the Network Slice Management 311 Function(NSMF) acquires the properties of network slice related 312 requirement that should be supported by the network slice instance in 313 5G network, which is defined in Service Profile([TS28541] section 314 6.3.3). 316 3. NSMF needs to decide on the constituent NSSIs(including AN NSSI, 317 CN NSSI and TN NSSI) to be created using the information from service 318 profile and the endpoint information(AN/CN edge nodes) . So NSMF 319 derives transport network slice related requirements from the Service 320 profile, and maintains them in Transport Network Slice Profile. So 321 as to CN Slice Profile and AN Slice Profile. 323 4. Transport Network Slice Profile is sent to TN NSSMF to request 324 allocation of the required TN NSSI(s). 326 5. TN NSSMF allocates TN network slicing subnet instance(TN NSSI) 327 which could satisfy the requirement between the specified endpoints 328 (AN/CN edge nodes) in Transport Network Slice Profile and sends the 329 TN NSSI Identifier to NSMF. 331 6. NSMF acquires the mapping relationship between NSI Identifier and 332 TN NSSI Identifier. 334 7. When a PDU session is set up between AN and CN, S-NSSAI is used 335 to choose network slice instance for the PDU session. 337 8. For a user packet in a particular network slice that to be sent 338 to transport network, the AN/CN edge nodes encapsulate the packet 339 using the transport network slice interworking identifier (TNSII) 340 according to the S-NSSAI or the NSI. Network Slice could also be 341 differentiated by physical interface, if different network slices are 342 transported through different interface; 344 9. The edge node of transport network parses the TNSII from the 345 packet and maps the packet to the corresponding transport network 346 slice. It may encapsulate a transport network slice identifier 347 (TNSI) into the packet. . 349 10. The nodes in transport network transit the packet inside the 350 corresponding transport network slice. 352 The procedure of end-to-end network slice mapping involves the 353 mapping in three network planes: management plane, control plane and 354 data plane. 356 4.1. Network Slice Mapping in Management Plane 358 The transport network management Plane maintains the interface 359 between NSMF and TN NSSMF, which 1) guarantees that transport network 360 slice could connect the AN and CN with specified characteristics that 361 satisfy the requirements of communication; 2) builds up the mapping 362 relationship between NSI identifier and TN NSSI identifier; 3) 363 maintains the end-to-end slice relevant functions; 364 Service Profile defined in[TS28541] represents the requirement of 365 end-to-end network slice instance in 5G network. Parameters defined 366 in Service Profile include Latency, resource sharing level, 367 availability and so on. How to decompose the end-to-end requirement 368 to the transport network requirement is one of the key issues in 369 Network slice requirement mapping. GSMA(Global System for Mobile 370 Communications Association) defines the [GST] to indicate the network 371 slice requirement from the view of service provider. 372 [I-D.contreras-teas-slice-nbi] analysis the parameters of GST and 373 categorize the parameters into three classes, including the 374 attributes with direct impact on the transport network slice 375 definition. It is a good start for selecting the transport network 376 relevant parameters in order to define Network Slice Profile for 377 Transport Network. Network slice requirement parameters are also 378 necessary for the definition of transport network northbound 379 interface. 381 Inside the TN NSSMF, it is supposed to maintain the attributes of the 382 transport network slice. If the attributes of an existing TN NSSI 383 could satisfy the requirement from TN Network Slice Profile, the 384 existing TN NSSI could be selected and the mapping is finished If 385 there is no existing TN NSSI which could satisfy the requirement, a 386 new TN NSSI is supposed to be created by the NSSMF with new 387 attributes. 389 TN NSSI resource reservation should be considered to avoid over 390 allocation from multiple requests from NSMF (but the detailed 391 mechanism should be out of scope in the draft) 393 TN NSSMF sends the selected or newly allocated TN NSSI identifier to 394 NSMF. The mapping relationship between NSI identifier and TN NSSI 395 identifier is maintained in both NSMF and TN NSSMF. 397 4.2. Network Slice Mapping in Control Plane 399 There is no explicit interaction between transport network and AN/CN 400 in the control plane, but the S-NSSAI defined in[TS23501] is treated 401 as the end-to-end network slice identifier in the control plane of AN 402 and CN, which is used in UE registration and PDU session setup. In 403 this draft, we assume that there is mapping relationship between 404 S-NSSAI and NSI in the management plane, thus it could be mapped to a 405 transport network slice . 407 Editor's note: The mapping relationship between NSI defined in 408 [TS23501] and S-NSSAI defined in [TS23501] is still in discussion. 410 4.3. Network Slice Mapping in data plane 412 If multiple network slices are carried through one physical interface 413 between AN/CN and TN, transport network slice interworking 414 identifier(TNSII) in the data plane needs to be introduced. If 415 different network slices are transported through different physical 416 interfaces, Network Slices could be distinguished by the interface 417 directly. Thus TNSII is not the only option for network slice 418 mapping, while it may help in introducing new network slices. 420 4.3.1. Data Plane Mapping Considerations 422 The mapping relationship between AN or CN network slice identifier 423 (either S-NSSAI in control plane or NSI/NSSI in management plane) and 424 TNSII needs to be maintained in AN/CN network nodes, and the mapping 425 relationship between TNSII and TNSI is maintained in the edge node of 426 transport network. When the packet of a uplink flow goes from AN to 427 TN, the packet is encapsulated based on the TNSII; then the 428 encapsulation of TNSII is read by the edge node of transport network, 429 which maps the packet to the corresponding transport network slice. 431 Editor's Note: We have considered to add "Network Instance" defined 432 in [TS23501]in the draft. However, after the discussion with 3GPP 433 people, we think the concept of "network instance" is a 'neither 434 Necessary nor Sufficient Condition' for network slice. Network 435 Instance could be determined by S-NSSAI, it could also depends on 436 other information; Network slice could also be allocated without 437 network instance (in my understanding) And, TNSII is not a 438 competitive concept with network instance.TNSII is a concept for the 439 data plane interconnection with transport network, network instance 440 may be used by AN and CN nodes to associate a network slice with 441 TNSII 443 4.3.2. Data Plane Mapping Design 445 The following picture shows the end-to-end network slice in data 446 plane: 448 +--+ +-----+ +----------------+ 449 |UE|- - - -|(R)AN|---------------------------| UPF | 450 +--+ +-----+ +----------------+ 451 |<----AN NS---->|<----------TN NS---------->|<----CN NS----->| 453 The mapping between 3GPP slice and transport slice in user plane 454 could happens in: 456 (R)AN: User data goes from (radio) access network to transport 457 network 459 UPF: User data goes from core network functions to transport network 461 Editor's Note: As figure 4.7.1. in [TS28530] describes, TN NS will 462 not only exist between AN and CN but may also within AN NS and CN NS. 463 However, here we just show the TN between AN and CN as an example to 464 avoid unncessary complexity. 466 The following picture shows the user plane protocol stack in end-to- 467 end 5G system. 469 +-----------+ | | | 470 |Application+--------------------|------------------|---------------| 471 +-----------+ | | +-----------+ | 472 | PDU Layer +--------------------|------------------|-| PDU Layer | | 473 +-----------+ +-------------+ | +-------------+ | +-----------+ | 474 | | | ___Relay___ |--|--| ___Relay___ |-|-| | | 475 | | | \/ GTP-U|--|--|GTP-U\/ GTP-U|-|-| GTP-U | | 476 | 5G-AN | |5G-AN +------+ | +------+------+ | +-----------+ | 477 | Protocol | |Protoc|UDP/IP|--|--|UDP/IP|UDP/IP|-|-| UDP/IP | | 478 | Layers | |Layers+------+ | +------+------+ | +-----------+ | 479 | | | | L2 |--|--| L2 | L2 |-|-| L2 | | 480 | | | +------+ | +------+------+ | +-----------+ | 481 | | | | L1 |--|--| L1 | L1 |-|-| L1 | | 482 +-----------+ +-------------+ | +-------------+ | +-----------+ | 483 UE 5G-AN | UPF | UPF | 484 N3 N9 N6 486 The following figure shows the typical encapsulation in N3 interface 487 which could be used to carry the transport network slice interworking 488 identifier (TNSII) between AN/CN and TN. 490 +------------------------+ 491 | Application Protocols | 492 +------------------------+ 493 | IP (User) | 494 +------------------------+ 495 | GTP | 496 +------------------------+ 497 | UDP | 498 +------------------------+ 499 | IP | 500 +------------------------+ 501 | Ethernet | 502 +------------------------+ 504 4.3.2.1. Layer 3 and Layer 2 Encapsulations 506 If the encapsulation above IP layer is not visible to Transport 507 Network, it is not able to be used for network slice interworking 508 with transport network. In this case, IP header and Ethernet header 509 could be considered to provide information of network slice 510 interworking from AN or CN to TN. 512 +------------------------+----------- 513 | Application Protocols | ^ 514 +------------------------+ | 515 | IP (User) | Invisible 516 +------------------------+ for 517 | GTP | TN 518 +------------------------+ | 519 | UDP | V 520 +------------------------+------------ 521 | IP | 522 +------------------------+ 523 | Ethernet | 524 +------------------------+ 526 The following field in IP header and Ethernet header could be 527 considered : 529 IP Header: 531 o DSCP: It is traditionally used for the mapping of QoS identifier 532 between AN/CN and TN network. Although some values (e.g. The 533 unassigned code points) may be borrowed for the network slice 534 interworking, it may cause confusion between QoS mapping and 535 network slicing mapping.; 537 o Destination Address: It is possible to allocate different IP 538 addresses for entities in different network slice, then the 539 destination IP address could be used as the network slice 540 interworking identifier. However, it brings additional 541 requirement to IP address planning. In addition, in some cases 542 some AN or CN network slices may use duplicated IP addresses. 544 o Option fields/headers: It requires that both AN and CN nodes can 545 support the encapsulation and decapsulation of the options. 547 Ethernet header 549 o VLAN ID: It is widely used for the interconnection between AN/CN 550 nodes and the edge nodes of transport network for the access to 551 different VPNs. One possible problem is that the number of VLAN 552 ID can be supported by AN nodes is typically limited, which 553 effects the number of transport network slices a AN node can 554 attach to. Another problem is the total amount of VLAN ID (4K) 555 may not provide a comparable space as the network slice 556 identifiers of mobile networks. 558 Two or more options described above may also be used together as the 559 TNSII, while it would make the mapping relationship more complex to 560 maintain. 562 In some other case, when AN or CN could support more layer 3 563 encapsulations, more options are available as follows: 565 If the AN or CN could support MPLS, the protocol stack could be as 566 follows: 568 +------------------------+----------- 569 | Application Protocols | ^ 570 +------------------------+ | 571 | IP (User) | Invisible 572 +------------------------+ for 573 | GTP | TN 574 +------------------------+ | 575 | UDP | V 576 +------------------------+------------ 577 | MPLS | 578 +------------------------+ 579 | IP | 580 +------------------------+ 581 | Ethernet | 582 +------------------------+ 584 A specified MPLS label could be used to as a TNSII. 586 If the AN or CN could support SRv6, the protocol stack is as follows: 588 +------------------------+----------- 589 | Application Protocols | ^ 590 +------------------------+ | 591 | IP (User) | Invisible 592 +------------------------+ for 593 | GTP | TN 594 +------------------------+ | 595 | UDP | V 596 +------------------------+------------ 597 | SRH | 598 +------------------------+ 599 | IPv6 | 600 +------------------------+ 601 | Ethernet | 602 +------------------------+ 604 The following field could be considered to identify a network slice: 606 SRH: 608 o SRv6 functions: AN/CN is supposed to support the new function 609 extension of SRv6. 611 o Optional TLV: AN/CN is supposed to support the extension of 612 optional TLV of SRH. 614 4.3.2.2. Above Layer 3 Encapsulations 616 If the encapsulation above IP layer is visible to Transport Network, 617 it is able to be used to identify a network slice. In this case, UPD 618 and GTP-U could be considered to provide information of network slice 619 interworking between AN or CN and TN. 621 +------------------------+---------- 622 | Application Protocols | | 623 +------------------------+ Invisible 624 | IP (User) | for 625 +------------------------+ TN 626 | GTP | | 627 +------------------------+------------ 628 | UDP | 629 +------------------------+ 630 | IP | 631 +------------------------+ 632 | Ethernet | 633 +------------------------+ 635 The following field in UDP header could be considered: 637 UDP Header: 639 o UDP Source port: The UDP source port is sometimes used for load 640 balancing. Using it for network slice mapping would require to 641 disable the load-balancing behavior. 643 5. Network Slice Mapping Summary 645 The following picture shows the mapping relationship between the 646 network slice identifier in management plane, control plane and user 647 plane. 649 AN/CN | TN 650 Management +---------+ | +---------+ 651 Plane | NSI |<--------|------->| TN NSSI | 652 +---------+ | +---------+ 653 | | | 654 | | | 655 Control +-----V-----+ | +----------+----------+ 656 Plane | S-NSSAI | | | | 657 +-----------+ | | | 658 | +----V----+ +----V----+ 659 +----------->| TNSII |<--------->| TNSI | 660 User | /Port |<--------->| | 661 Plane +---------+ +---------+ 662 | 664 6. IANA Considerations 666 TBD 668 Note to RFC Editor: this section may be removed on publication as an 669 RFC. 671 7. Security Considerations 673 TBD 675 8. Acknowledgements 677 The authors would like to thank Shunsuke Homma for reviewing the draft and 678 giving valuable comments. 680 9. Normative References 682 [GST] "Generic Network Slice Template", 2016, 683 . 686 [I-D.contreras-teas-slice-nbi] 687 Contreras, L., Homma, S., and J. Ordonez-Lucena, 688 "Considerations for defining a Transport Slice NBI", 689 draft-contreras-teas-slice-nbi-00 (work in progress), 690 November 2019. 692 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 693 Requirement Levels", BCP 14, RFC 2119, 694 DOI 10.17487/RFC2119, March 1997, 695 . 697 [TS23501] "3GPP TS23.501", 2016, 698 . 701 [TS28530] "3GPP TS28.530", 2016, 702 . 705 [TS28531] "3GPP TS28.531", 2016, 706 . 709 [TS28541] "3GPP TS 28.541", 2016, 710 . 713 [ZSM003] "End to end management and orchestration of network 714 slicing", 2016, 715 . 718 Authors' Addresses 720 Xuesong Geng 721 Huawei Technologies 723 Email: gengxuesong@huawei.com 725 Jie Dong 726 Huawei Technologies 728 Email: jie.dong@huawei.com 729 Tomonobu Niwa 730 KDDI 732 Email: to-niwa@kddi.com 734 Jaewhan JIN 735 LG U+ 737 Email: daenamu1@lguplus.co.kr