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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 (July 13, 2020) is 1383 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Outdated reference: A later version (-06) exists of draft-contreras-teas-slice-nbi-01 Summary: 1 error (**), 0 flaws (~~), 3 warnings (==), 1 comment (--).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: January 14, 2021 R. Pang 6 China Unicom 7 L. Han 8 China Mobile 9 T. Niwa 10 KDDI 11 J. Jin 12 LG U+ 13 C. Liu 14 China Unicom 15 N. Nageshar 16 Individual 17 July 13, 2020 19 5G End-to-end Network Slice Mapping from the view of Transport Network 20 draft-geng-teas-network-slice-mapping-02 22 Abstract 24 Network Slicing is one of the core featrures in 5G. End-to-end 25 network slice consists of 3 major types of network segments: Access 26 Network (AN), Mobile Core Network (CN) and Transport Network (TN). 27 This draft describes the procedure of mapping relationship between 5G 28 end-to-end network slice and transport network slice defined in IETF. 29 This draft also intends to expose some gaps in the existing network 30 management plane and data plane to support inter-domain network slice 31 mapping. Further work may require cooperation between IETF and 3GPP 32 (or other standard organizations). The definition of data model, 33 signaling protocol extension and new encapsulation are out of the 34 scope of this draft. 36 Requirements Language 38 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 39 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 40 document are to be interpreted as described in RFC 2119 [RFC2119]. 42 Status of This Memo 44 This Internet-Draft is submitted in full conformance with the 45 provisions of BCP 78 and BCP 79. 47 Internet-Drafts are working documents of the Internet Engineering 48 Task Force (IETF). Note that other groups may also distribute 49 working documents as Internet-Drafts. The list of current Internet- 50 Drafts is at https://datatracker.ietf.org/drafts/current/. 52 Internet-Drafts are draft documents valid for a maximum of six months 53 and may be updated, replaced, or obsoleted by other documents at any 54 time. It is inappropriate to use Internet-Drafts as reference 55 material or to cite them other than as "work in progress." 57 This Internet-Draft will expire on January 14, 2021. 59 Copyright Notice 61 Copyright (c) 2020 IETF Trust and the persons identified as the 62 document authors. All rights reserved. 64 This document is subject to BCP 78 and the IETF Trust's Legal 65 Provisions Relating to IETF Documents 66 (https://trustee.ietf.org/license-info) in effect on the date of 67 publication of this document. Please review these documents 68 carefully, as they describe your rights and restrictions with respect 69 to this document. Code Components extracted from this document must 70 include Simplified BSD License text as described in Section 4.e of 71 the Trust Legal Provisions and are provided without warranty as 72 described in the Simplified BSD License. 74 Table of Contents 76 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 77 2. Terminologies . . . . . . . . . . . . . . . . . . . . . . . . 3 78 3. Network Slice Mapping Structure . . . . . . . . . . . . . . . 4 79 3.1. Requirements Profile . . . . . . . . . . . . . . . . . . 5 80 3.2. Identifiers . . . . . . . . . . . . . . . . . . . . . . . 6 81 3.3. Relevant functions . . . . . . . . . . . . . . . . . . . 6 82 4. Network Slice Mapping Procedure . . . . . . . . . . . . . . . 7 83 4.1. Network Slice Mapping in Management Plane . . . . . . . . 8 84 4.2. Network Slice Mapping in Control Plane . . . . . . . . . 9 85 4.3. Network Slice Mapping in data plane . . . . . . . . . . . 10 86 4.3.1. Data Plane Mapping Considerations . . . . . . . . . . 10 87 4.3.2. Data Plane Mapping Design . . . . . . . . . . . . . . 10 88 5. Network Slice Mapping Summary . . . . . . . . . . . . . . . . 15 89 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 90 7. Security Considerations . . . . . . . . . . . . . . . . . . . 15 91 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 92 9. Normative References . . . . . . . . . . . . . . . . . . . . 15 93 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 95 1. Introduction 97 Driven by the new applications of 5G, the concept of network slicing 98 is defined to provide a logical network with specific capabilities 99 and characteristics. Network slice contains a set of network 100 functions and allocated resources(e.g. Computation, storage and 101 network resources). According to [TS28530], a 5G end-to-end network 102 slice is composed of three major types network segments: Radio Access 103 Network (RAN), Transport Network (TN) and Mobile Core Network (CN). 104 Transport network is supposed to provide the required connectivity 105 between AN and CN, which specific performance commitment. For each 106 end-to-end network slice, the topology and performance requirement 107 for transport network can be very different, which requires transport 108 network to have the capability of supporting multiple different 109 transport network slices. 111 A transport network slice is a virtual (logical) network with a 112 particular network topology and a set of shared or dedicated network 113 resources, which are used to provide the network slice consumer with 114 the required connectivity, appropriate isolation and specific Service 115 Level Agreement (SLA). A transport network slice could span multiple 116 technology (IP, Optical) and multiple administrative domains. 117 Depending on the consumer's requirement, a transport network slice 118 could be isolated from other concurrent transport network slices, in 119 terms of data plane, control plane and management plane. Transport 120 network slice is being defined and discussed in IETF. 122 Editor's Note: The work of 124 The procedure of end-to-end network slice instance creation, network 125 slice subnet instance creation and network slice instance termination 126 in management plane are defined in [TS28531]. The end-to-end network 127 slice allocation is defined in ETSI [ZSM003]. But there is no 128 specifications about how to map end-to-end network slice in 5G system 129 to transport network slice. This draft describes the procedure of 130 mapping 5G end-to-end network slice into transport network slice in 131 management plane, control plane and user plane. 133 2. Terminologies 135 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 136 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 137 document are to be interpreted as described in [RFC2119]. 139 The following terms are used in this document: 141 NS: Network Slice 142 NSI: Network Slice Instance 144 NSSI: Network Slice Subnet Instance 146 NSSAI: Network Slice Selection Assistance Information 148 S-NSSAI: Single Network Slice Selection Assistance Information 150 AN: Access Network 152 RAN: Radio Access Network 154 TN: Transport Network 156 CN: Mobile Core Network 158 DSCP: Differentiated Services Code Point 160 CSMF: Communication Service Management Function 162 NSMF: Network Slice Management Function 164 NSSMF: Network Slice Subnet Management Function 166 GST: General Slice Template 168 TNSII: Transport Network Slice Interworking Identifier 170 TNSI: Transport Network Slice Identifier 172 PDU: Protocol Data Unit 174 Editor's Note: Terminologies defined in 3GPP, e.g.,Network Slice 175 Subnet Management Function(NSSMF), Network Slice Subnet 176 Instance(NSSI) and Network Slice Selection Assistance 177 Information(NSSAI), is used in the end-to-end network slice mapping, 178 which may not be used necessarily within the transport network. 180 3. Network Slice Mapping Structure 182 The following figure shows the necessary elements for mapping end-to- 183 end network slice into transport network slice. All these network 184 slice elements are classified into three groups: requirements/ 185 capabilities, identifiers and relevant functions. 187 +-----------------+ 188 | CSMF | 189 +--------+--------+ 190 | 191 +--------V--------+ 192 | NSMF | 193 +-----------------+ 194 +----------| NSI Identifier |----------+ 195 | | Service Profile | | 196 | | TN Network- | | 197 | | -Slice Profile | | 198 | +-----------------+ | 199 | | | 200 +------V------+ +----------V----------+ +------V------+ 201 | AN NSSMF | | TN NSSMF | | CN NSSMF | 202 +-------------+ +---------------------+ +-------------+ 203 | AN-NSSI- | | TN-NSSI Identifier | | CN-NSSI- | 204 | -Identifier | | Function Management| | -Identifier | 205 | ... | | ... | | ... | Management 206 +-------------+ +---------------------+ +-------------+ Plane 207 | | | | ----------------- 208 |<----------PDU session (S-NSSAI)---------->| Control 209 | | | | Plane 210 V V V V ----------------- 211 /\ +-----+ +-----+ +-------+ Data 212 /AN\ -----| PE |-----...-----| PE |----| UPF | Plane 213 /____\ +-----+ +-----+ +-------+ 214 |-->TNSII<--|------>TNSI<-------|-->TNSII<--| 216 3.1. Requirements Profile 218 In order to satisfy a tenant's request for a network slice with 219 certain characteristics, creating a new network slice or using 220 existing network slice instance is constrained by the customer's 221 requirement and the capability of the network slices. 223 o Service Profile: represents the properties of network slice 224 related requirement that should be supported by the network slice 225 instance in 5G network. Service profile is defined in [TS28541] 226 6.3.3. 228 o TN Network Slice Profile: represents the properties of transport 229 network slice related requirement that should be supported by the 230 transport network slice in a 5G network. Slice Profile is defined 231 in [TS28541] 6.3.4. TN Network slice profile is newly defined in 232 this draft. 234 3.2. Identifiers 236 Network slice related identifiers in management plane, control plane 237 and user(data) plane play an important role in end-to-end network 238 slice mapping. 240 o Single Network Slice Selection Assistance Information(S-NSSAI): 241 end-to-end network slice identifier in control plane, which is 242 defined in [TS23501]; 244 o Network Slice Instance(NSI) Identifier:end-to-end network slice 245 identifier in management plane, which is created in NSMF; NSI is 246 is set of Network Function instances and the required resources 247 (e.g. compute, storage and networking resources) which form a 248 deployed Network Slice, which is defined in [TS23501]; ; 250 o Transport Network Slice Instance(TN-NSSI) Identifier: transport 251 network slice identifier in management plane, which is created in 252 TN NSSMF; TN-NSSI is newly defined in this draft. 254 o Transport Network Slice Interworking Identifier (TNSII): network 255 slice identifier which is used for mapping end-to-end network 256 slice into transport network slice in user plane. TNSII is newly 257 defined in this draft. 259 o Transport Network Slice Identifier(TNSI): transport network slice 260 identifier in data plane(user plane). TNSI is newly defined in 261 this draft. 263 The relationship between these identifiers are specifies in the 264 following sections. 266 3.3. Relevant functions 268 There are a set of slice relevant functions that are necessary for 269 transport network slice management: 271 o Topology management 273 o QoS management 275 o Resource management 277 o Measurement management 279 o ... 281 Some of these functions are implemented inside the transport network 282 and independent from the end-to-end network slice, e.g., topology 283 management, QoS management, resource management; Some of the 284 functions are related to the end-to-end network slice and should 285 cooperate with other network elements from other domain, e.g., 286 Measurement management. 288 4. Network Slice Mapping Procedure 290 This section provides a general procedure of network slice mapping: 292 +--------------------------------+ 293 | Requirement Matching | 294 +---------------+----------------+ 295 | 296 V 297 +--------------------------------+ 298 | NSI<->TN NSSI Mapping | 299 +---------------+----------------+ 300 | 301 V 302 +--------------------------------+ 303 | S-NSSAI Selection | 304 +---------------+----------------+ 305 | 306 V 307 +--------------------------------+ 308 |S-NSSAI<---------->TNSII Mapping| 309 | (NSI<->TN NSSI) | 310 +---------------+----------------+ 311 | 312 V 313 +--------------------------------+ 314 | TNSII<->TNSI Mapping | 315 +--------------------------------+ 317 1. NSMF receives the request from CSMF for allocation of a network 318 slice instance with certain characteristics. 320 2. Based on the service requirement , NSMF acquires requirements for 321 the end-to-end network slice instance , which is defined in Service 322 Profile([TS28541] section 6.3.3). 324 3. NSMF derives transport network slice related requirements from 325 the Service profile, and maintains them in Transport Network Slice 326 Profile, So as to CN Slice Profile and AN Slice Profile, in order to 327 decide on the constituent NSSIs(including AN NSSI, CN NSSI and TN 328 NSSI) of the NSI, based on the service profile and the endpoint 329 information(AN/CN edge nodes). 331 4. NSMF sends the Transport Network Slice Profile, endpoint 332 information, along with other TS NBI attributes to TN NSSMF for TN 333 NSSI allocation. 335 5. TN NSSMF allocates TN NSSI which could satisfy the requirement of 336 Transport Network Slice Profile between the specified endpoints (AN/ 337 CN edge nodes) and sends the TN NSSI Identifier to NSMF. 339 6. NSMF acquires the mapping relationship between NSI and TN NSSI. 341 7. NSMF matains the mapping relationship between NSI and S-NSSAI and 342 the mapping relationship between TN NSSI and TNSII, which could be 343 used to set up mapping relationship between S-NSSAI and TNSII. 345 8. When a PDU session is set up between AN and CN, an S-NSSAI is 346 slected for the PDU session. 348 9. AN/CN edge nodes encapsulate the packet using TNSII, according to 349 the selected S-NSSAI. Network Slice could also be differentiated by 350 physical interface, if different network slices are transported 351 through different interface; 353 10. The edge node of transport network parses the TNSII from the 354 packet and maps the packet to the corresponding transport network 355 slice. It may encapsulate packet with TNSI. The nodes in transport 356 network transit the packet inside the corresponding transport network 357 slice according to TNSI. 359 The procedure of end-to-end network slice mapping involves the 360 mapping in three network planes: management plane, control plane and 361 data plane. 363 4.1. Network Slice Mapping in Management Plane 365 The transport network management Plane maintains the interface 366 between NSMF and TN NSSMF, which 1) guarantees that transport network 367 slice could connect the AN and CN with specified characteristics that 368 satisfy the requirements of communication; 2) builds up the mapping 369 relationship between NSI identifier and TN NSSI identifier; 3) 370 maintains the end-to-end slice relevant functions; 372 Service Profile defined in[TS28541] represents the requirement of 373 end-to-end network slice instance in 5G network. Parameters defined 374 in Service Profile include Latency, resource sharing level, 375 availability and so on. How to decompose the end-to-end requirement 376 to the transport network requirement is one of the key issues in 377 Network slice requirement mapping. GSMA(Global System for Mobile 378 Communications Association) defines the [GST] to indicate the network 379 slice requirement from the view of service provider. 380 [I-D.contreras-teas-slice-nbi] analysis the parameters of GST and 381 categorize the parameters into three classes, including the 382 attributes with direct impact on the transport network slice 383 definition. It is a good start for selecting the transport network 384 relevant parameters in order to define Network Slice Profile for 385 Transport Network. Network slice requirement parameters are also 386 necessary for the definition of transport network northbound 387 interface. 389 Inside the TN NSSMF, it is supposed to maintain the attributes of the 390 transport network slice. If the attributes of an existing TN NSSI 391 could satisfy the requirement from TN Network Slice Profile, the 392 existing TN NSSI could be selected and the mapping is finished If 393 there is no existing TN NSSI which could satisfy the requirement, a 394 new TN NSSI is supposed to be created by the NSSMF with new 395 attributes. 397 TN NSSI resource reservation should be considered to avoid over 398 allocation from multiple requests from NSMF (but the detailed 399 mechanism should be out of scope in the draft) 401 TN NSSMF sends the selected or newly allocated TN NSSI identifier to 402 NSMF. The mapping relationship between NSI identifier and TN NSSI 403 identifier is maintained in both NSMF and TN NSSMF. 405 YANG data model for the Transport Slice NBI, which could be used by a 406 higher level system which is the Transport slice consumer of a 407 Transport Slice Controller (TSC) to request, configure, and manage 408 the components of a transport slices, is defined in 409 [I-D.wd-teas-transport-slice-yang]. 411 4.2. Network Slice Mapping in Control Plane 413 There is no explicit interaction between transport network and AN/CN 414 in the control plane, but the S-NSSAI defined in [TS23501] is treated 415 as the end-to-end network slice identifier in the control plane of AN 416 and CN, which is used in UE registration and PDU session setup. In 417 this draft, we assume that there is mapping relationship between 418 S-NSSAI and NSI in the management plane, thus it could be mapped to a 419 transport network slice . 421 Editor's note: The mapping relationship between NSI defined in 422 [TS23501] and S-NSSAI defined in [TS23501] is still in discussion. 424 4.3. Network Slice Mapping in data plane 426 If multiple network slices are carried through one physical interface 427 between AN/CN and TN, transport network slice interworking 428 identifier(TNSII) in the data plane needs to be introduced. If 429 different network slices are transported through different physical 430 interfaces, Network Slices could be distinguished by the interface 431 directly. Thus TNSII is not the only option for network slice 432 mapping, while it may help in introducing new network slices. 434 4.3.1. Data Plane Mapping Considerations 436 The mapping relationship between AN or CN network slice identifier 437 (either S-NSSAI in control plane or NSI/NSSI in management plane) and 438 TNSII needs to be maintained in AN/CN network nodes, and the mapping 439 relationship between TNSII and TNSI is maintained in the edge node of 440 transport network. When the packet of a uplink flow goes from AN to 441 TN, the packet is encapsulated based on the TNSII; then the 442 encapsulation of TNSII is read by the edge node of transport network, 443 which maps the packet to the corresponding transport network slice. 445 Editor's Note: We have considered to add "Network Instance" defined 446 in [TS23501]in the draft. However, after the discussion with 3GPP 447 people, we think the concept of "network instance" is a 'neither 448 Necessary nor Sufficient Condition' for network slice. Network 449 Instance could be determined by S-NSSAI, it could also depends on 450 other information; Network slice could also be allocated without 451 network instance (in my understanding) And, TNSII is not a 452 competitive concept with network instance.TNSII is a concept for the 453 data plane interconnection with transport network, network instance 454 may be used by AN and CN nodes to associate a network slice with 455 TNSII 457 4.3.2. Data Plane Mapping Design 459 The following picture shows the end-to-end network slice in data 460 plane: 462 +--+ +-----+ +----------------+ 463 |UE|- - - -|(R)AN|---------------------------| UPF | 464 +--+ +-----+ +----------------+ 465 |<----AN NS---->|<----------TN NS---------->|<----CN NS----->| 467 The mapping between 3GPP slice and transport slice in user plane 468 could happens in: 470 (R)AN: User data goes from (radio) access network to transport 471 network 473 UPF: User data goes from core network functions to transport network 475 Editor's Note: As figure 4.7.1. in [TS28530] describes, TN NS will 476 not only exist between AN and CN but may also within AN NS and CN NS. 477 However, here we just show the TN between AN and CN as an example to 478 avoid unncessary complexity. 480 The following picture shows the user plane protocol stack in end-to- 481 end 5G system. 483 +-----------+ | | | 484 |Application+--------------------|------------------|---------------| 485 +-----------+ | | +-----------+ | 486 | PDU Layer +--------------------|------------------|-| PDU Layer | | 487 +-----------+ +-------------+ | +-------------+ | +-----------+ | 488 | | | ___Relay___ |--|--| ___Relay___ |-|-| | | 489 | | | \/ GTP-U|--|--|GTP-U\/ GTP-U|-|-| GTP-U | | 490 | 5G-AN | |5G-AN +------+ | +------+------+ | +-----------+ | 491 | Protocol | |Protoc|UDP/IP|--|--|UDP/IP|UDP/IP|-|-| UDP/IP | | 492 | Layers | |Layers+------+ | +------+------+ | +-----------+ | 493 | | | | L2 |--|--| L2 | L2 |-|-| L2 | | 494 | | | +------+ | +------+------+ | +-----------+ | 495 | | | | L1 |--|--| L1 | L1 |-|-| L1 | | 496 +-----------+ +-------------+ | +-------------+ | +-----------+ | 497 UE 5G-AN | UPF | UPF | 498 N3 N9 N6 500 The following figure shows the typical encapsulation in N3 interface 501 which could be used to carry the transport network slice interworking 502 identifier (TNSII) between AN/CN and TN. 504 +------------------------+ 505 | Application Protocols | 506 +------------------------+ 507 | IP (User) | 508 +------------------------+ 509 | GTP | 510 +------------------------+ 511 | UDP | 512 +------------------------+ 513 | IP | 514 +------------------------+ 515 | Ethernet | 516 +------------------------+ 518 4.3.2.1. Layer 3 and Layer 2 Encapsulations 520 If the encapsulation above IP layer is not visible to Transport 521 Network, it is not able to be used for network slice interworking 522 with transport network. In this case, IP header and Ethernet header 523 could be considered to provide information of network slice 524 interworking from AN or CN to TN. 526 +------------------------+----------- 527 | Application Protocols | ^ 528 +------------------------+ | 529 | IP (User) | Invisible 530 +------------------------+ for 531 | GTP | TN 532 +------------------------+ | 533 | UDP | V 534 +------------------------+------------ 535 | IP | 536 +------------------------+ 537 | Ethernet | 538 +------------------------+ 540 The following field in IP header and Ethernet header could be 541 considered : 543 IP Header: 545 o DSCP: It is traditionally used for the mapping of QoS identifier 546 between AN/CN and TN network. Although some values (e.g. The 547 unassigned code points) may be borrowed for the network slice 548 interworking, it may cause confusion between QoS mapping and 549 network slicing mapping.; 551 o Destination Address: It is possible to allocate different IP 552 addresses for entities in different network slice, then the 553 destination IP address could be used as the network slice 554 interworking identifier. However, it brings additional 555 requirement to IP address planning. In addition, in some cases 556 some AN or CN network slices may use duplicated IP addresses. 558 o Option fields/headers: It requires that both AN and CN nodes can 559 support the encapsulation and decapsulation of the options. 561 Ethernet header 563 o VLAN ID: It is widely used for the interconnection between AN/CN 564 nodes and the edge nodes of transport network for the access to 565 different VPNs. One possible problem is that the number of VLAN 566 ID can be supported by AN nodes is typically limited, which 567 effects the number of transport network slices a AN node can 568 attach to. Another problem is the total amount of VLAN ID (4K) 569 may not provide a comparable space as the network slice 570 identifiers of mobile networks. 572 Two or more options described above may also be used together as the 573 TNSII, while it would make the mapping relationship more complex to 574 maintain. 576 In some other case, when AN or CN could support more layer 3 577 encapsulations, more options are available as follows: 579 If the AN or CN could support MPLS, the protocol stack could be as 580 follows: 582 +------------------------+----------- 583 | Application Protocols | ^ 584 +------------------------+ | 585 | IP (User) | Invisible 586 +------------------------+ for 587 | GTP | TN 588 +------------------------+ | 589 | UDP | V 590 +------------------------+------------ 591 | MPLS | 592 +------------------------+ 593 | IP | 594 +------------------------+ 595 | Ethernet | 596 +------------------------+ 598 A specified MPLS label could be used to as a TNSII. 600 If the AN or CN could support SRv6, the protocol stack is as follows: 602 +------------------------+----------- 603 | Application Protocols | ^ 604 +------------------------+ | 605 | IP (User) | Invisible 606 +------------------------+ for 607 | GTP | TN 608 +------------------------+ | 609 | UDP | V 610 +------------------------+------------ 611 | SRH | 612 +------------------------+ 613 | IPv6 | 614 +------------------------+ 615 | Ethernet | 616 +------------------------+ 618 The following field could be considered to identify a network slice: 620 SRH: 622 o SRv6 functions: AN/CN is supposed to support the new function 623 extension of SRv6. 625 o Optional TLV: AN/CN is supposed to support the extension of 626 optional TLV of SRH. 628 4.3.2.2. Above Layer 3 Encapsulations 630 If the encapsulation above IP layer is visible to Transport Network, 631 it is able to be used to identify a network slice. In this case, UPD 632 and GTP-U could be considered to provide information of network slice 633 interworking between AN or CN and TN. 635 +------------------------+---------- 636 | Application Protocols | | 637 +------------------------+ Invisible 638 | IP (User) | for 639 +------------------------+ TN 640 | GTP | | 641 +------------------------+------------ 642 | UDP | 643 +------------------------+ 644 | IP | 645 +------------------------+ 646 | Ethernet | 647 +------------------------+ 649 The following field in UDP header could be considered: 651 UDP Header: 653 o UDP Source port: The UDP source port is sometimes used for load 654 balancing. Using it for network slice mapping would require to 655 disable the load-balancing behavior. 657 5. Network Slice Mapping Summary 659 The following picture shows the mapping relationship between the 660 network slice identifier in management plane, control plane and user 661 plane. 663 AN/CN | TN 664 Management +---------+ | +---------+ 665 Plane | NSI |<--------|------->| TN NSSI | 666 +---------+ | +---------+ 667 | | | 668 | | | 669 Control +-----V-----+ | +----------+----------+ 670 Plane | S-NSSAI | | | | 671 +-----------+ | | | 672 | +----V----+ +----V----+ 673 +----------->| TNSII |<--------->| TNSI | 674 User | /Port |<--------->| | 675 Plane +---------+ +---------+ 676 | 678 6. IANA Considerations 680 TBD 682 Note to RFC Editor: this section may be removed on publication as an 683 RFC. 685 7. Security Considerations 687 TBD 689 8. Acknowledgements 691 The authors would like to thank Shunsuke Homma for reviewing the 692 draft and giving valuable comments. 694 9. Normative References 696 [GST] "Generic Network Slice Template", 697 . 700 [I-D.contreras-teas-slice-nbi] 701 Contreras, L., Homma, S., and J. Ordonez-Lucena, 702 "Considerations for defining a Transport Slice NBI", 703 draft-contreras-teas-slice-nbi-01 (work in progress), 704 March 2020. 706 [I-D.wd-teas-transport-slice-yang] 707 Bo, W., Dhody, D., Han, L., and R. Rokui, "A Yang Data 708 Model for Transport Slice NBI", draft-wd-teas-transport- 709 slice-yang-02 (work in progress), July 2020. 711 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 712 Requirement Levels", BCP 14, RFC 2119, 713 DOI 10.17487/RFC2119, March 1997, 714 . 716 [TS23501] "3GPP TS23.501", 717 . 720 [TS28530] "3GPP TS28.530", 721 . 724 [TS28531] "3GPP TS28.531", 725 . 728 [TS28541] "3GPP TS 28.541", 729 . 732 [ZSM003] "ETSI ZSM003", 733 . 736 Authors' Addresses 738 Xuesong Geng 739 Huawei Technologies 741 Email: gengxuesong@huawei.com 743 Jie Dong 744 Huawei Technologies 746 Email: jie.dong@huawei.com 747 Ran Pang 748 China Unicom 750 Email: pangran@chinaunicom.cn 752 Liuyan Han 753 China Mobile 755 Email: hanliuyan@chinamobile.com 757 Tomonobu Niwa 758 KDDI 760 Email: to-niwa@kddi.com 762 Jaehwan Jin 763 LG U+ 765 Email: daenamu1@lguplus.co.kr 767 Chang Liu 768 China Unicom 770 Email: liuc131@chinaunicom.cn 772 Nikesh Nageshar 773 Individual 775 Email: nikesh.nageshar@gmail.com