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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) No issues found here. Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Mobility for IPv4 Working Group S. Gundavelli, Ed. 3 Internet-Draft K. Leung 4 Intended status: Standards Track Cisco 5 Expires: December 25, 2014 G. Tsirtsis 6 Qualcomm 7 H. Soliman 8 Elevate Technologies 9 A. Petrescu 10 CEA LIST 11 June 23, 2014 13 Flow Binding Support for Mobile IP 14 draft-ietf-mip4-multiple-tunnel-support-08.txt 16 Abstract 18 This specification defines extensions to Mobile IP protocol for 19 allowing a mobile node with multiple interfaces to register a care-of 20 address for each of its network interfaces and to simultaneously 21 establish multiple IP tunnels with its home agent. This essentially 22 allows the mobile node to utilize all the available network 23 interfaces and build an higher aggregated logical pipe with its home 24 agent for its home address traffic. Furthermore, these extensions 25 also allow the mobile node and the home agent to negotiate flow 26 policies for binding individual traffic flows with the registered 27 care-of addresses. 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 http://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 December 25, 2014. 46 Copyright Notice 48 Copyright (c) 2014 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 (http://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 . . . . . . . . . . . . . . . . . . . . . . . . . 3 64 2. Conventions and Terminology . . . . . . . . . . . . . . . . . 3 65 2.1. Conventions . . . . . . . . . . . . . . . . . . . . . . . 3 66 2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 67 3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 4 68 3.1. Example Call Flow . . . . . . . . . . . . . . . . . . . . 5 69 4. Message Extensions . . . . . . . . . . . . . . . . . . . . . . 6 70 4.1. Multipath Extension . . . . . . . . . . . . . . . . . . . 6 71 4.2. Flow-Binding Extension . . . . . . . . . . . . . . . . . . 9 72 4.3. New Error Codes for Registration Reply . . . . . . . . . . 11 73 5. Protocol Operation . . . . . . . . . . . . . . . . . . . . . . 11 74 5.1. Mobile Node Considerations . . . . . . . . . . . . . . . . 11 75 5.2. Home Agent Considerations . . . . . . . . . . . . . . . . 13 76 6. Routing Considerations . . . . . . . . . . . . . . . . . . . . 14 77 7. Protocol Configuration Variables . . . . . . . . . . . . . . . 14 78 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 79 9. Security Considerations . . . . . . . . . . . . . . . . . . . 15 80 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 16 81 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16 82 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 83 12.1. Normative References . . . . . . . . . . . . . . . . . . . 16 84 12.2. Informative References . . . . . . . . . . . . . . . . . . 17 86 1. Introduction 88 With the ubiquitous availability of wireless networks supporting 89 different access technologies, mobile devices are now equipped with 90 multiple wireless interfaces and have the ability to connect to the 91 network over any of those interfaces and access the network. In many 92 deployments, it is desirable for a mobile node to leverage all the 93 available network connections and have IP mobility support for its IP 94 sessions. 96 The operation defined in the Mobile IP Protocol [RFC5944], allows a 97 mobile node to continue to use its home address as it moves around 98 the internet. Based on the mode of operation, there will be a Mobile 99 IP tunnel that will be established between the home agent and the 100 mobile node, or between the home agent and the foreign agent where 101 the mobile node is attached. In both of these modes, there will only 102 be one interface on the mobile node that is receiving the traffic 103 from the home agent. However, this is not efficient and requires an 104 approach where the mobile node can use more than one interfaces for 105 reaching the home network. The objective being efficient use of all 106 available links to obtain higher aggregated bandwidth for the 107 tunneled traffic between the home agent and the mobile node. 109 This specification defines extensions to Mobile IPv4 protocol for 110 allowing a mobile node with multiple interfaces to register a care-of 111 address for each of its network interfaces and to simultaneously 112 establish multiple IP tunnels with its home agent. Furthermore, this 113 specification also defines extensions to allow the mobile node and 114 the home agent to optionally negotiate flow policies for binding 115 individual traffic flows with the registered care-of addresses. 117 2. Conventions and Terminology 119 2.1. Conventions 121 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 122 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 123 document are to be interpreted as described in RFC 2119 [RFC2119]. 125 2.2. Terminology 127 All the mobility related terms used in this document are to be 128 interpreted as defined in [RFC5944] and [RFC3753]. In addition this 129 document uses the following terms. 131 Binding Identifier (BID) 132 It is an identifier for a specific binding of a mobile node. A 133 binding defines an association between a mobile node's home 134 address and its registered care-of address. A mobile node, when 135 it registers multiple bindings with its home agent, each using 136 different care-of addresses, then each of those bindings are given 137 a unique identifier. The Binding Identifier is unique within all 138 the bindings for a given mobile node. 140 Flow Identifier (FID) 142 It is an identifier for a given IP flow, uniquely identified by 143 source address, destination address, protocol type, source port 144 and destination port. In the context of this document, the IP 145 flows associated with a mobile node are the IP flows using its 146 home address. 148 3. Solution Overview 150 The illustration below in Figure-1 is of a mobile node attached to 151 the network over three different access technologies, Wi-Fi, LTE and 152 CDMA. The mobile node is assigned an home address, HoA-1, and has 153 configured the care-of addresses CoA-1 (Wi-Fi), CoA-2 (LTE) and CoA-3 154 (CDMA). The mobile node has registered the three care-of addresses 155 with the home agent and has established Mobile IP tunnels, Tunnel-1, 156 Tunnel-2 and Tunnel-3 over each of those access networks. The IP 157 traffic using mobile node's home address (HoA-1) can be routed 158 through any of the three tunnel paths. The mobile node's IP flows, 159 Flow-1, Flow-2 and Flow-3 are routed between the home agent and the 160 mobile node over these different Mobile IP tunnels based on the 161 negotiated flow policy. 163 Flow-1 164 | 165 |Flow-2 166 | | 167 | |Flow-3 _----_ 168 | | | CoA-1 _( )_ Tunnel-1 169 | | | .---=======( Wi-Fi )========\ Flow-1 170 | | | | (_ _) \ 171 | | | | '----' \ 172 | | | +=====+ _----_ \ +=====+ _----_ 173 | | '-| | CoA-2 _( )_ Tunnel-2 \ | | _( )_ -- 174 | '---| MN |---====( LTE )=========-----| HA |-( Internet )-- 175 '-----| | (_ _) Flow-3 / | | (_ _) -- 176 +=====+ '----' / +=====+ '----' 177 | | _----_ / 178 HoA-1--' | CoA-3 _( )_ Tunnel-3 / 179 .------====( CDMA )========/ Flow-2 180 (_ _) 181 '----' 183 Figure 1: Mobile Node with multiple tunnels to the home agent 185 The above table is an example of how the individual flows are bound 186 to different care-of addresses registered with the home agent. 188 +-------+----------------------+------------------------------------+ 189 | Flow | CoA/Tunnel/BID | Negotiated Flow Policy | 190 | Id | | | 191 +-------+----------------------+------------------------------------+ 192 | 1. | CoA-1/Tunnel-1/BID-1 | All SIP Flows over WiFI | 193 | 2. | CoA-2/Tunnel-2/BID-2 | All HTTP Flows over LTE | 194 | 3. | CoA-3/Tunnel-3/BID-3 | All SSH Flows over CDMA | 195 +-------+----------------------+------------------------------------+ 197 Table 1: Example - Flow Binding Table 199 3.1. Example Call Flow 201 Figure 2 shows a scenario where a mobile node is attached two WLAN 202 and LTE access networks negotiates multipath support with the home 203 agent. Furthermore, the mobile node and the home agent also 204 negotiate the flow policies which bind specific application traffic 205 to specific access networks. 207 +-------+ +-------+ +-------+ +-------+ 208 | MN | | WLAN | | LTE | | HA | 209 | | |Network| |Network| | | 210 +-------+ +-------+ +-------+ +-------+ 211 | | | | 213 * MIP Registration of the Care-of Address obtained from WLAN Network 215 |<--- (1) --------->| | | 216 | | RRQ (Multipath, Flow-Binding) | 217 |---- (2) ----------------------------------------------->| 218 | | RRP | | 219 |<--- (3) ------------------------------------------------| 220 | MIP Tunnel through WLAN Network | 221 |=====(4)===========*=====================================| 223 * MIP Registration of the Care-of Address obtained from LTE Network 225 |<--- (5) ---------------------------->| | 226 | | RRQ (Multipath, Flow-Binding) | 227 |---- (6) ----------------------------------------------->| 228 | | RRP | | 229 |<--- (7) ------------------------------------------------| 230 | MIP Tunnel through LTE Access | 231 |=====(8)==============================*==================| 232 | | 233 * * 234 (Policy-based Routing Rule) (Policy-based Routing Rule) 236 Figure 2: Multipath Negotiation - Call Flow 238 4. Message Extensions 240 This specification defines the following new extensions to Mobile IP. 242 4.1. Multipath Extension 244 This extension is used for requesting multipath support. It 245 indicates that the sender is requesting the home agent to register 246 the current care-of address listed in this Registration Request as 247 one of the many care-addresses through which the mobile node can be 248 reached. It is also for carrying the information specific to the 249 interface to which the care-of addresses that is being registered is 250 bound. 252 This extension is a non-skippable extension and MAY be added by the 253 mobile node to the Registration Request message. There MUST NOT be 254 more than one instance of this extension present in the message. 255 This extension MUST NOT be added by the home agent or by the foreign 256 agent either to the Registration Request or to the Registration 257 Reply. 259 This extension should be protected using the Mobile-Home 260 Authentication extension [RFC5944]. As specified in Section 3.2 and 261 Section 3.6.1.3 of [RFC5944], the mobile node MUST place this 262 Extension before the Mobile-Home Authentication Extension in the 263 registration messages, so that this extension is integrity protected. 265 The format of this extension is as shown below. It adheres to the 266 short extension format described in [RFC5944]. 268 0 1 2 3 269 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 270 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 271 | Type | Length | Sub-Type | If-ATT | 272 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 273 | If-Label | Binding-Id |B|O| Reserved | 274 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 276 Figure 3: Multipath Extension 278 Type 280 Type: 282 Length 284 The length of the extension in octets, excluding Type and 285 Length fields. This field MUST be set to value of 6. 287 Sub-Type 289 This field MUST be set to a value of 1 (Multipath Extension). 291 Interface Access-Technology Type (If-ATT) 293 This 8-bit field identifies the Access-Technology type of the 294 interface through which the mobile node is connected. The 295 permitted values for this are from the Access Technology Type 296 registry defined in [RFC5213]. 298 Interface Label (If-Label) 300 This 8-bit field represents the interface label represented as 301 an unsigned integer. The mobile node identifies the label for 302 each of the interfaces through which it registers a CoA with 303 the home agent. When using static traffic flow policies on the 304 mobile node and the home agent, the label can be used for 305 generating forwarding policies. For example, the operator may 306 have policy which binds traffic for Application "X" needs to 307 interface with Label "Y". When a registration through an 308 interface matching Label "Y" gets activated, the home agent and 309 the mobile node can dynamically generate a forwarding policy 310 for forwarding traffic for Application "X" through mobile IP 311 tunnel matching Label "Y". Both the home agent and the mobile 312 node can route the Application-X traffic through that 313 interface. The permitted values for If-Label are 1 through 314 255. 316 Binding-Identifier (BID) 318 This 8-bit field is used for carrying the binding identifier. 319 It uniquely identifies a specific binding of the mobile node, 320 to which this request can be associated. Each binding 321 identifier is represented as an unsigned integer. The 322 permitted values are 1 through 254. The BID value of 0 and 255 323 are reserved. The mobile node assigns a unique value for each 324 of its interfaces and includes them in the message. 326 Bulk Re-registration Flag (B) 328 This flag, if set to a value of (1), is to notify the home 329 agent to consider this request as a request to update the 330 binding lifetime of all the mobile node's bindings, upon 331 accepting this specific request. This flag MUST NOT be set to 332 a value of (1), if the value of the Registration Overwrite Flag 333 (O) flag is set to a value of (1). 335 Registration Overwrite (O) 337 This flag, if set to a value of (1), notifies the home agent 338 that upon accepting this request, it should replace all of the 339 mobile node's existing bindings with this binding. This flag 340 MUST NOT be set to a value of (1), if the value of the Bulk Re- 341 registration Flag (B) is set to a value of (1). This flag MUST 342 be set to a value of (0), in de-registration requests. 344 Reserved (R) 346 This 14-bit field is unused for now. The value MUST be 347 initialized to (0) by the sender and MUST be ignored by the 348 receiver. 350 4.2. Flow-Binding Extension 352 This extension contains information that can be used by the mobile 353 node and the home agent for binding mobile node's IP flows to a 354 specific multipath registration. There can be more than one instance 355 of this extension present in the message. 357 This extension is a non-skippable extension and MAY be added to the 358 Registration Request by the mobile node, or by the home agent to the 359 Registration Reply. There MUST NOT be more than one instance of this 360 extension present in the message. This extension MUST NOT be added 361 by the foreign agent either to the Registration Request or to the 362 Registration Reply. 364 This extension should be protected by Mobile-Home Authentication 365 extension [RFC5944]. As specified in Section 3.2 and Section 3.6.1.3 366 of [RFC5944], the mobile node MUST place this Extension before the 367 Mobile-Home Authentication Extension in the registration messages, so 368 that this extension is integrity protected. 370 The format of this extension is as shown below. It adheres to the 371 long extension format described in [RFC5944]. 373 0 1 2 3 374 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 375 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 376 | Type | Sub-Type | Length | 377 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 378 | Action | BID Count | ... BID List ... ~ 379 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 380 | TS Format | Traffic Selector ~ 381 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 383 Figure 4: Flow-Binding Extension 385 Type 386 Type: 388 Sub-Type 390 This field MUST be set to a value of 1 (Flow-Binding 391 Extension). 393 Length 395 The length of the extension in octets, excluding Type, Length 396 and Sub-Type fields. 398 Action 400 +---------+-------+-------------------------------------------------+ 401 | Action | Value | Comments | 402 +---------+-------+-------------------------------------------------+ 403 | Drop | 0 | Drop matching packets. A filter rule | 404 | | | indicating a drop action MUST include a single | 405 | | | BID byte, the value of which MAY be set to 255 | 406 | | | by the sender and the value of which SHOULD be | 407 | | | ignored by the receiver. | 408 | Forward | 1 | Forward matching packets to the 1st BID in the | 409 | | | list of BIDs the filter rule is pointing to. | 410 | | | If the 1st BID becomes invalid (i.e., the | 411 | | | corresponding CoA is deregistered) use the next | 412 | | | BID in the list. | 413 +---------+-------+-------------------------------------------------+ 415 Table 2: Action Rules for the Traffic Selector 417 BID Count 419 Total number of binding identifiers that follow this field. 420 Permitted value for this field are 1 through 8; Each binding 421 identifier is represented as an unsigned integer in a single 422 octet field. There is no delimiter between two binding 423 identifier values, they are spaced consecutively. 425 TS Format 427 An 8-bit unsigned integer indicating the Traffic Selector 428 Format. Value (0) is reserved and MUST NOT be used. When the 429 value of TS Format field is set to (1), the format that follows 430 is the IPv4 Binary Traffic Selector specified in section 3.1 of 431 [RFC6088], and when the value of TS Format field is set to (2), 432 the format that follows is the IPv6 Binary Traffic Selector 433 specified in section 3.2 of [RFC6088]. 435 Traffic Selector 437 A variable-length opaque field for including the traffic 438 specification identified by the TS format field. It identifies 439 the traffic selectors for matching the IP traffic and binding 440 them to specific binding identifiers. 442 4.3. New Error Codes for Registration Reply 444 This document defines the following error code values for use by the 445 home agent in the Code field of the Registration Reply. 447 MULTIPATH_NOT_ALLOWED (Multipath Support not allowed for this 448 mobility session): 450 INVALID_FB_IDENTIFIER (Invalid Flow Binding Identifier): 452 5. Protocol Operation 454 5.1. Mobile Node Considerations 456 The configuration variable, EnableMultipathSupport, determines if 457 multipath support is enabled or disabled on the mobile node. If 458 multipath support is not enabled, then this specification does not 459 apply. If multipath support is enabled on a mobile node, then the 460 following considerations apply. 462 o The mobile node should register a care-of address for each of the 463 active egress interfaces that it wishes to register with the home 464 agent. It can do so by sending a Registration Request to the home 465 agent through each of those interfaces. 467 o Each of the Registration Requests that is sent MUST include the 468 care-of address of the respective interface. The Registration 469 Request has to be routed through the specific interface for which 470 the registration is sough for. Some of these interfaces may be 471 connected to networks with a configured foreign agent on the link 472 and in such foreign agent based registrations, the care-of address 473 MUST be the address of the foreign agent. 475 o A Multipath extension Section 4.1 reflecting the interface 476 parameters MUST be present in each of the Registration Requests. 477 This serves as an indication to the home agent that the 478 Registration Request is a Multipath registration and the home 479 agent MUST register this care-of address as one of the many 480 care-of addresses through which the mobile node's home address is 481 reachable. The mobile node MUST place this Extension before the 482 Mobile-Home Authentication Extension in the Registration Request 483 message. 485 o If the mobile node is configured to exchange IP flow policy to the 486 home agent, then the Flow-Binding extension Section 4.2 reflecting 487 the flow policy can be included in the message. Otherwise, the 488 Flow-Binding extension MUST NOT be present in the message. 490 o The mobile node on receiving a Registration Reply with the code 491 value set to MULTIPATH_NOT_ALLOWED, MAY choose to register without 492 the Multipath extension specified in this document. This implies 493 the home agent has not enabled multipath support for this mobility 494 session and hence multipath support must be disabled on the mobile 495 node. 497 o The mobile node on receiving a Registration Reply with the code 498 value set to INVALID_FB_IDENTIFIER, MUST re-register that specific 499 binding for with the home agent. 501 o The mobile node at any time can extend the lifetime of a specific 502 care-of address registration by sending a Registration Request to 503 the home agent with a new lifetime value. The message MUST be 504 sent as the initial multipath registration and must be routed 505 through that specific interface. The message MUST include the 506 Multipath extension Section 4.1 with the value in the Binding-Id 507 field set to the binding identifier assigned to that binding. 508 Alternatively, the home agent can send a single Registration 509 Request with the Bulk Re-registration Flag (B) set to a value of 510 (1). This serves as a request to the home agent to consider this 511 request as a request to update the registration lifetime of all 512 the mobile node's registrations. 514 o The mobile node at any time can de-register a specific care-of 515 address by sending a Registration Request to the home agent with a 516 lifetime value of (0). The message MUST be sent as the initial 517 multipath registration and must be routed through that specific 518 interface. The message must include the Multipath extension 519 Section 4.1 with the value in the Binding-Id field set to the 520 binding identifier assigned to that binding Alternatively, the 521 home agent can send a single Registration Request with the Bulk 522 Re-registration Flag (B) set to a value of (1) and a lifetime 523 value of (0). This serves as a request to the home agent to 524 consider this request as a request to de-register all the mobile 525 node's care-of addresses. 527 o The mobile node at any time can update the parameters of a 528 specific registration by sending a Registration Request to the 529 home agent. This includes change of care-of address associated 530 with a previously registered interface. The message must be sent 531 as the initial multipath registration and must be routed through 532 that specific interface. The message must include the Multipath 533 extension Section 4.1 with the value in the Binding-Id field set 534 to the binding identifier assigned to that binding and the 535 Overwrite Flag (O) flag MUST set to a value of (1). 537 o The mobile node on receiving a Registration Reply with the code 538 value set to 0 (registration accepted), MUST establish a mobile IP 539 tunnel to the home agent using that care-of address. The tunnel 540 encapsulation type and any other parameters are based on the 541 registration for that path. If there is also an exchange of flow 542 policy between the mobile node and the home agent, with the use of 543 Flow-Binding extensions then the mobile node must set up the 544 forwarding plane that matches the flow policy. 546 5.2. Home Agent Considerations 548 The home agent upon receipt of a Registration Request with the 549 Multipath extension from a mobile node, should check the 550 configuration variable, EnableMultipathSupport. If the value of this 551 variable is set to 0, the home agent MUST reject the request with a 552 registration reply and with the code set to MULTIPATH_NOT_ALLOWED. 554 The home agent upon receipt of a Registration Request with the 555 Multipath extension and with the Bulk Re-registration (B) flag in the 556 request set to a value of (1), the home agent upon accepting the 557 request MUST extend the lifetime of all the mobile node's bindings. 559 The home agent upon receipt of a Registration Request with the Flow- 560 Binding Extension must process the extension and upon accepting the 561 flow policy must set up the forwarding plane that matches the flow 562 policy. If the home agent cannot identify any of the binding 563 identifiers then it MUST reject the request with a Registration Reply 564 and with the code set to INVALID_FB_IDENTIFIER. 566 The home agent upon receipt of a Registration Request with the 567 Multipath extension and if the (O) flag in the request set to a value 568 of 1, the home agent upon accepting the request MUST consider this as 569 a request to replace all other mobile node's bindings with just one 570 binding and that is the binding associated with this request. 572 6. Routing Considerations 574 When multipath is enabled for a mobility session, there are 575 potentially multiple mobile IP tunnels established between a mobile 576 node and its home agent. These Mobile IP tunnels appear to the 577 forwarding plane as equal-cost, point-to-point links. 579 If there is also an exchange of flow policy between the mobile node 580 and the home agent, with the use of Flow-Binding extensions 581 Section 4.2, then the mobile node's IP traffic can be routed by the 582 mobility entities as per the negotiated flow policy. However, if 583 multipath is enabled for a mobility session, without the use of any 584 flow policy exchange, then both the mobile node and the home agent 585 are required to have a pre-configured static flow policy. The 586 specific details on the semantics of this static flow policy is 587 outside the scope of this document. 589 In the absence of any established traffic flow policies, most IP 590 hosts support two alternative traffic load-balancing schemes, Per- 591 flow and Per-packet load balancing. These load balancing schemes 592 allow the forwarding plane to evenly distribute traffic based on the 593 criteria of either a per-packet or on a per-flow basis, across all 594 the available equal-cost links through which a destination can be 595 reached. The default forwarding behavior of Per-flow load balancing 596 will ensure a given flow always takes the same path and will 597 eliminate any packet re-ordering issues and that is critical for 598 delay sensitive traffic. Whereas the per-destination load balancing 599 scheme leverages all the paths much more affectively, but with the 600 potential issue of packet re-ordering on the receiver end. A host 601 can choose to enable any of these approaches. Therefore, this 602 specification recommends the use of per-flow load balancing. 604 7. Protocol Configuration Variables 606 The following protocol configuration variables are required for 607 system management and these variables MUST be configurable on all the 608 mobility entities. The configured values for these protocol 609 variables MUST survive service restarts. 611 EnableMultipathSupport 613 This flag indicates whether or not the mobility entity on which 614 this protocol variable is configured needs to enable Multipath 615 support feature. This protocol variable is applicable to both the 616 home agent and the mobile node. 618 The default value for this flag is set to value of (1), indicating 619 that the multipath support is enabled. 621 When the value for this flag is set to value of (0), multipath 622 support is disabled. 624 8. IANA Considerations 626 This document requires the following IANA actions. 628 o Action-1: This specification defines a new Mobile IP extension, 629 Multipath extension. It is a non-skippable extension to the 630 Mobile IPv4 header in accordance to the short extension format of 631 [RFC5944]. The format of this option is described in Section 4.1. 632 The type value for this extension needs to be allocated 633 from the registry, "Extensions to Mobile IP Registration 634 Messages", at < http://www.iana.org/assignments/mobileip-numbers/ 635 mobileip-numbers.xhtml>. RFC Editor: Please replace in 636 Section 4.1 with the assigned value and update this section 637 accordingly. 639 o Action-2: This specification defines a new Mobile IP extension, 640 Flow-Binding extension. It is a non-skippable extension to the 641 Mobile IPv4 header in accordance to the long extension format of 642 [RFC5944]. The format of this option is described in Section 4.2. 643 The type value for this extension needs to be allocated 644 from the registry, "Extensions to Mobile IP Registration 645 Messages", at < http://www.iana.org/assignments/mobileip-numbers/ 646 mobileip-numbers.xhtml>. RFC Editor: Please replace in 647 Section 4.2 with the assigned value and update this section 648 accordingly. 650 o Action-3: This document defines new status code value, 651 MULTIPATH_NOT_ALLOWED (), INVALID_FB_IDENTIFIER () 652 for use by the home agent in the Code field of the Registration 653 Reply, as described in Section 4.3. This value needs to be 654 assigned from the "Registration denied by the home agent" registry 655 at . The 656 allocated value has to be greater than 127. RFC Editor: Please 657 replace in Section 4.3 with the assigned value and update 658 this section accordingly. 660 9. Security Considerations 662 This specification allows a mobile node to establish multiple Mobile 663 IP tunnels with its home agent, by registering a care-of address for 664 each of its active roaming interfaces. This essentially allows the 665 mobile node's IP traffic to be routed through any of the tunnel paths 666 based on a static or a dynamically negotiated flow policy. This new 667 capability has no impact on the protocol security. Furthermore, this 668 specification defines two new Mobile IP extensions, Multipath 669 extension and the Flow-Binding extension. These extensions are 670 specified to be included in Mobile IP control messages, which are 671 authenticated and integrity protected as described in [RFC5944]. 672 Therefore, this specification does not weaken the security of Mobile 673 IP Protocol, and does not introduce any new security vulnerabilities. 675 10. Contributors 677 This document reflects discussions and contributions from the 678 following people: 680 Ahmad Muhanna 682 asmuhanna@yahoo.com 684 Srinivasa Kanduru 686 skanduru@gmail.com 688 Vince Park 690 vpark@qualcomm.com 692 11. Acknowledgements 694 We like to thank Qin Wu, Shahriar Rahman, Mohana Jeyatharan, Yungui 695 Wang, Hui Deng Behcet Sarikaya, Jouni Korhonen, Michaela Vanderveen 696 and Antti Makela for their review and comments on this draft. 698 12. References 700 12.1. Normative References 702 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 703 Requirement Levels", BCP 14, RFC 2119, March 1997. 705 [RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., 706 and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008. 708 [RFC5944] Perkins, C., "IP Mobility Support for IPv4, Revised", 709 RFC 5944, November 2010. 711 [RFC6088] Tsirtsis, G., Giarreta, G., Soliman, H., and N. Montavont, 712 "Traffic Selectors for Flow Bindings", RFC 6088, 713 January 2011. 715 12.2. Informative References 717 [RFC3753] Manner, J. and M. Kojo, "Mobility Related Terminology", 718 RFC 3753, June 2004. 720 Authors' Addresses 722 Sri Gundavelli (editor) 723 Cisco 724 170 West Tasman Drive 725 San Jose, CA 95134 726 USA 728 EMail: sgundave@cisco.com 730 Kent Leung 731 Cisco 732 170 West Tasman Drive 733 San Jose, CA 95134 734 USA 736 EMail: kleung@cisco.com 738 George Tsirtsis 739 Qualcomm 741 EMail: tsirtsis@qualcomm.com 743 Hesham Soliman 744 Elevate Technologies 746 EMail: hesham@elevatemobile.com 748 Alexandru Petrescu 749 CEA LIST 750 Communicating Systems Laboratory, Point Courrier 94 751 Gif-sur-Yvette F-91191 752 France 754 Phone: +33 169089223 755 EMail: alexandru.petrescu@cea.fr