DMM WG P. Seite Internet-Draft Orange Intended status: Standards Track A. Yegin Expires:January 1,March 10, 2018 Actility S. Gundavelli CiscoJune 30,September 6, 2017 MAG Multipath Binding Optiondraft-ietf-dmm-mag-multihoming-04.txtdraft-ietf-dmm-mag-multihoming-05.txt Abstract This specification defines extensions to the Proxy Mobile IPv6 protocol for allowing a mobile access gateway to register more than one proxy care-of-address with the local mobility anchor and to simultaneously establish multiple IP tunnels with the local mobility anchor. This capability allows the mobile access gateway to utilize all the available access networks for routing mobile node's IP traffic. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. 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Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions and Terminology . . . . . . . . . . . . . . . . . 4 2.1. Conventions . . . . . . . . . . . . . . . . . . . . . . . 5 2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5 3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Example Call Flow . . . . . . . . . . . . . . . . . . . . 5 3.2. Traffic distribution schemes . . . . . . . . . . . . . . .67 4. Protocol Extensions . . . . . . . . . . . . . . . . . . . . .78 4.1. MAG Multipath-Binding Option . . . . . . . . . . . . . . .78 4.2. MAG Identifier Option . . . . . . . . . . . . . . . . . .910 4.3. New Status Code for Proxy Binding Acknowledgement . . . .1011 4.4. Signaling Considerations . . . . . . . . . . . . . . . . . 11 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . .1112 6. Security Considerations . . . . . . . . . . . . . . . . . . .1112 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .1213 8. References . . . . . . . . . . . . . . . . . . . . . . . . . .1213 8.1. Normative References . . . . . . . . . . . . . . . . . . .1213 8.2. Informative References . . . . . . . . . . . . . . . . . .1314 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .1314 1. Introduction Multihoming support on IP hosts can greatly improve the user experience. With the simultaneoous use of multiple access networks, multihoming brings better network connectivity, reliability and improved quality of communication. Following are some of the goals and benefits of multihoming support: o Redundancy/Fault-Recovery o Load balancing o Load sharing o Preferences settings According to [RFC4908], users of Small-Scale Networks can take benefit of multihoming using mobile IP [RFC6275] and Network Mobility (NEMO) [RFC3963] architecture in a mobile and fixed networking environment. This document is introducing the concept of multiple Care-of Addresses (CoAs) [RFC5648] that have been specified since then. The motivation for this work is to extend Proxy Mobile IPv6 protocol with multihoming extensions [RFC4908] for realizing the following capabilities: o using GRE as mobile tuneling, possibly with its key extension [RFC5845] (a possible reason to use GRE is given on Section 3.2). o using UDP encapsulation [RFC5844] in order to support NAT traversal in IPv4 networking environment. o Prefix Delegation mechanism [RFC7148]. o Using the vendor specific mobility option [RFC5094], for example to allow the MAG and LMA to exchange information (e.g. WAN interface QoS metrics) allowing to make appropriate traffic steering decision. Proxy Mobile IPv6 (PMIPv6) relies on two mobility entities: the mobile access gateway (MAG), which acts as the default gateway for the end-node and the local mobility anchor (LMA), which acts as the topological anchor point. Point-to-point links are established, using IP-in-IP tunnels, between MAG and LMA. Then, the MAG and LMA are distributing traffic over these tunnels. All PMIPv6 operations are performed on behalf of the end-node and its corespondent node, it thus makes PMIPv6 well adapted to multihomed architecture as considered in [RFC4908]. Taking the LTE and WLAN networking environments as an example, the PMIPv6 based multihomed architecture is depicted on Figure 1. Flow-1,2 and 3 are distributed either on Tunnel-1 (over LTE) or Tunnel-2 (over WLAN), while Flow-4 is spread on both Tunnel-1 and 2. Flow-1 | |Flow-2 _----_ | | CoA-1 _( )_ Tunnel-1 | | .---=======( LTE )========\ Flow-1 | | | (_ _) \Flow-4 | | | '----' \ | | +=====+ \ +=====+ _----_ | '-| | \ | | _( )_ '---| MAG | | LMA |-( Internet )-- .---| | | | (_ _) | .-| | / | | '----' | | +=====+ / +=====+ | | | _----_ / | | | CoA-2 _( )_ Tunnel-2 / | | .---=======( WLAN )========/ Flow-2 | | (_ _) Flow-3 | | '----'Flow-4|Flow-3 | Flow0-4 Figure 1: Multihomed MAG using Proxy Mobile IPv6 The current version of Proxy Mobile IPv6 does not allow a MAG to register more than one proxy Care-of-Adresse to the LMA. In other words, only one MAG/LMA link, i.e. IP-in-IP tunnel, can be used at the same time. This document overcomes this limitation by defining the multiple proxy Care-of Addresses (pCoAs) extension for Proxy Mobile IPv6. 2. Conventions and Terminology 2.1. Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. 2.2. Terminology All mobility related terms used in this document are to be interpreted as defined in [RFC5213], [RFC5844] and [RFC7148]. Additionally, this document uses the following terms: IP-in-IP IP-within-IP encapsulation [RFC2473], [RFC4213] 3. Overview 3.1. Example Call Flow Figure 2 is the callflow detailing multi-access support with PMIPv6. The MAG in this example scenario is equipped with both WLAN and LTE interfaces and is also configured with the multihoming functionality. The steps of the callflow are as follows: Steps (1) and (2): the MAG attaches to both WLAN and LTE networks; the MAG obtains respectively two different proxy care-of-addresses (pCoA). Step (3): The MAG sends, over the WLAN access, a Proxy Binding Update (PBU) message, with the new MAG Multipath Binding (MMB) and MAG Identifier (MAG-NAI) options to the LMA. The request can be for a physical mobile node attached to the MAG, or for a logical mobile node configured on the mobile node. Alogical-NAI (MAG-NAI) with ALWAYS-ON configurationlogical mobile node is ALWAYS- ATTACHED mobile node configuration enabled on the MAG. The mobility session that is created (i.e. create a Binding Cache Entry) on the LMAis for the logical-NAI. The LMA and allocates a Home Network Prefix (HNP), that shallwill bedelegated to mobile nodes, to the MAG.marked with multipath support. Step (4): the LMA sends back a Proxy Binding Acknowledgement (PBA) including the HNP and other session parameters allocatedto the MAG.for that mobility session. Step (5): IP tunnel (IP-in-IP, GRE ...) is created over the WLAN access. Steps (6) to (8): The MAG repeats steps (3) to (5) on the LTE access. The MAG includes the HNP, received on step (4) in the PBU. The LMA update its binding cache by creating a new mobility session for this MAG. Steps (9) and (10): The IP hosts MN_1 and MN_2 are assigned IP addresses from the mobile network prefix delegated by the MAG. +=====+ +=====+ +=====+ +=====+ +=====+ +=====+ | MN_1| | MN_2| | MAG | | WLAN| | LTE | | LMA | +=====+ +=====+ +=====+ +=====+ +=====+ +=====+ | | | | | | | | | | | | | | | (1) ATTACH | | | | | | <--------> | | | | | | (2) ATTACH | | | | | <---------------------->| | | | | (3) PBU (MAG-NAI,MMB)MMB, ...) | | | | ------------------------*-------------->| | | | | | | | Accept PBU | | | (allocate HNP, | | | create BCE) | | | (4) PBA (MAG-NAI,HNP)MMB, ...) | | | | <-----------------------*---------------| | | | (5) TUNNEL INTERFACE CREATION over WLAN | | | |-============== TUNNEL ==*==============-| | | | | | | | (6) PBU (MAG-NAI,HNP, MMB)MMB, ...) | | | | -----------*--------------------------->| | | | | | | | Accept PBU | | | (update BCE) | | | (7) PBA (MAG-NAI,HNP)MMB, ...) | | | | <----------*--------------------------- | | | | (8) TUNNEL INTERFACE CREATION over LTE | | | |-===========*== TUNNEL =================-| | (9) ATTACH | | | <---------------> | | | |(10) ATTACH| | | |<--------> | | Figure 2: Functional Separation of the Control and User Plane 3.2. Traffic distribution schemes Whenreceiving packets fromtheMN,MAG has registered multipath binding with the LMA, there will be multiple established overlay tunnels between them. The MAGdistributes packets overand the LMA can use any one, or more of the available tunnels paths for routing the mobile node's IP traffic. This specification does not recommend, or define any specific traffic distribution scheme, however it identifies two well-known approaches thathave been established.implementations can potentially use. These approaches are, Per-flow and Per-packet Traffic distributioncan be managed either on a per-flow or on a per-packet basis:schemes. Per-Flow Traffic Distribution: oPer-flow traffic management:In this approach the MAG and the LMA associate each of the IPflow (both upstreamflows (upstream and downstream)is mappedto agiven tunnel, corresponding tospecific tunnel path. The packets in a givenWAN interface. Flow binding extension [RFC6089] is used to exchange, and synchronize,IP flowmanagement policies (i.e. rules associating traffic selectors [RFC6088] to a tunnel). o Per-packet management: the LMA andare always routed on theMAG distribute packets, belonging to asameIP flow, over more than one bindings (i.e.overlay tunnel path; they are never split and routed concurrently on more than oneWAN interface). Packet distribution cantunnel path. It is possible a given flow may bedone either at the transport level, e.g. using MPTCP or at When operating at the IP packet level, different packets distribution algorithms are possible. For example,moved from one tunnel path to another, but thealgorithm may give precedenceflow is never split. The decision toonebind a givenaccess:IP flow to a specific tunnel path is based on traffic distribution policy. This traffic distribution policy is either statically configured on both the MAGoverflowsand the LMA, or dynamically negotiated over Proxy Mobile IPv6 signaling. The Flow Binding extension [RFC6089] and Traffic Selectors for Flow Bindings [RFC6088] defines the mechanism and the semantics for exchanging the trafficfrompolicy between two tunnel peers and theprimary access, e.g. WLAN, tosame mechanism and thesecond one, only when load on primary access reachesmobility options are used here. Per-Packet Traffic Distribution: o In this approach, packets belonging a giventhreshold.IP flow will be split and routed across more than one tunnel paths. The exact approach for traffic distribution, or the distributionalgorithmweights isleft to implementer but whateveroutside the scope of this specification. In a very simplistic approach, assuming the established tunnel paths have symmetric characteristics, thealgorithm is, packets distribution likely introduces packet latency and out-of- order delivery. LMA and MAG shall thus be able to make reordering beforepacketsdelivery. Sequence numbercan be equally distributed on all the available tunnel paths. In a different scenario when the links have different speeds, the chosen approach can beused for that purpose, for example using GRE with sequence number option [RFC5845]. However, more detailed considerationsbased onreordering and IP packetweighted distributionscheme (e.g. definition of packets distribution algorithm) are out the scope(Ex: n:m ratio). However, in any ofthis document. Because latency introduced by per-packet can cause injurythese chosen approaches, implementations have tosome application, per-flow and per-packet distribution schemes couldbeused in conjunction. For example, high throughput services (e.g. video streaming) may benefit from per-packet distribution scheme, while latencysensitiveapplications (e.g. VoIP) are not be spread over different WAN paths. IP flow mobility extensions, [RFC6089]to issues related to asymmetric link characteristics and[RFC6088], canthe resulting issues such as re-ordering, buffering and the impact to the application performance. Care must beusedtaken to ensure there is no negative impact toprovisiontheMAG with such flow policies.application performance due to the use of this approach. 4. Protocol Extensions 4.1. MAG Multipath-Binding Option The MAG Multipath-Binding option is a new mobility header option defined for use with Proxy Binding Update and Proxy Binding Acknowledgement messages exchanged between the local mobility anchor and the mobile access gateway. This mobility header option is used for requesting multipath support. It indicates that the mobile access gateway is requesting the local mobility anchor to register the current care-of address associated with the request as one of the many care-addresses through which the mobile access gateway can be reached. It is also for carrying the information related to the access network associated with the care-of address. The MAG Multipath-Binding option has an alignment requirement of 8n+2. Its format is as shown in Figure 3: 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | If-ATT | If-Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Binding-Id |B|O| RESERVED | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: MAG Multipath Binding Option Type <IANA-1> To be assigned by IANA. Length 8-bit unsigned integer indicating the length of the option in octets, excluding the type and length fields. Interface Access-Technology Type (If-ATT) This 8-bit field identifies the Access-Technology type of the interface through which the mobile node is connected. The permitted values for this are from the Access Technology Type registry defined in [RFC5213]. Interface Label (If-Label) This 8-bitfieldunsigned integer represents the interface label. The interface labelrepresented asis anunsigned integer. The MAG identifiesidentifier configured on thelabel for eachWAN interface of the MAG. All the WAN interfacesthrough which it registersof the MAG that are used for sending PBU messages are configured with apCoAlabel. The labels merely identify the type of WAN interface and are primarily used in Application routing policies. For example, a Wi-Fi interfaces can be configured with a label RED and a LTE interface with a label BLUE. Furthermore, theLMA. When using static traffic flow policiessame label may be configured on two WAN interfaces of similar characteristics (Ex: Two Ethernet interfaces with themobile node andsame label). Interfaces labels are signaled from theLMA,MAG to LMA in thelabel canPBU messages and both the LMA and MAG will be able to mark each of the dynamically created Binding/Tunnel with the associated label. These labels are usedforin generatingforwarding rules. For example,consistent application routing rules on theoperator may have policy which binds traffic for Application "X" to an interface with Label "Y". When a registration through an interface matching Label "Y" gets activated,both the LMA and themobile nodeMAG. For example, there candynamically generatebe aforwardingpolicyfor forwarding traffic for Application "X" through the tunnel matchingrequiring HTTP packets to be routed over interface that has Label"Y". Both the LMARED, and if any of themobile node can routeRED interfaces are not available, theApplication-Xtrafficthrough thatneeds to be routed over the BLUE interface. Thepermitted values for If-Label are 1 through 255.MAG and the LMA will be able to apply this Routing Rule with the exchange of Labels in PBU messages and by associating the application flows to tunnels with the matching labels. Binding-Identifier (BID) This 8-bitfieldunsigned integer is used forcarrying the binding identifier. It uniquely identifies a specific binding ofidentifying themobile node, to which this request can be associated. Each binding identifier is represented as an unsigned integer.binding. The permitted values are 1 through 254. TheBID value ofvalues, 0 and 255 are reserved. The MAG identifies each of the mobileaccess gateway assignsnode's binding with a uniquevalue for each of its interfaces andidentifier. The MAG includesthemthe identifier in themessage.PBU message and when the PBU request is accepted by the LMA, the resulting Binding is associated with this binding identifier. Bulk Re-registration Flag (B) This flag, if set to a value of (1), is to notify the local mobility anchor to consider this request as a request to update the binding lifetime of all the mobile node's bindings, upon accepting this specific request. This flag MUST NOT be set to a value of (1), if the value of the Registration Overwrite Flag (O) is set to a value of (1). Binding Overwrite (O) This flag, if set to a value of (1), notifies the local mobility anchor that upon accepting this request, it should replace all of the mobile node's existing bindings with this binding. This flag MUST NOT be set to a value of (1), if the value of the Bulk Re- registration Flag (B) is set to a value of (1). This flag MUST be set to a value of (0), in de-registration requests. Reserved This field is unused in this specification. The value MUST be set to zero (0) by the sender and MUST be ignored by the receiver. 4.2. MAG Identifier Option The MAG Identifier option is a new mobility header option defined for use with Proxy Binding Update and Proxy Binding Acknowledgement messages exchanged between the local mobility anchor and the mobile access gateway. This mobility header option is used for conveying the MAG's identity. This option does not have any alignment requirements. 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Subtype | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identifier ... ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: MAG Identifier Option Type <IANA-2> To be assigned by IANA. Length 8-bit unsigned integer indicating the length of the option in octets, excluding the type and length fields. Subtype One byte unsigned integer used for identifying the type of the Identifier field. Accepted values for this field are the registered type values from the Mobile Node Identifier Option Subtypes registry. Reserved This field is unused in this specification. The value MUST be set to zero (0) by the sender and MUST be ignored by the receiver. Identifier A variable length identifier of type indicated in the Subtype field. 4.3. New Status Code for Proxy Binding Acknowledgement This document defines the following new Status Code value for use in Proxy Binding Acknowledgement message. The LMA SHOULD use this error code when rejecting a Proxy Binding Update message from a MAG requesting a multipath binding. Following is the potential reason for rejecting the request: o The LMA does not support multipath binding. CANNOT_SUPPORT_MULTIPATH_BINDING (Cannot Support Multipath Binding): <IANA-4> 4.4. Signaling Considerations o The MAG when requesting multipath support MUST include the MAG Multipath Binding Option (Section 4.1) in each of the PBU messages that it sends through the different WAN interfaces. The inclusion of this option serves as a hint that the MAG is requesting Multipath support. Furthermore, the MAG Identifier option MUST also be present in the PBU message. o If the LMA is a legacy LMA that does not support this specification, the LMA will skip the MAG Multipath Binding option (and MAG NAI option) and process the rest of the message as specified in the base Proxy Mobile IPv6 specification ([RFC5213]). Furthermore, the LMA will not include the MAG Multipath Binding option (or the MAG NAI Option)in the PBA message. The MAG on receiving the PBA message without the MAG Multipath Binding option SHOULD disable Multipath support for the mobile node. o If the mobile node is not authorized for Multipath support, then the LMA will reject the request by sending a PBA message with the Status field value set to CANNOT_SUPPORT_MULTIPATH_BINDING (Section 4.3). The LMA will echo the MAG Multipath Binding option and the MAG NAI option in the PBA message. The MAG on receiving this message SHOULD disable Multipath support for the mobile node. o If the request for multipath support is accepted, then the LMA SHOULD enable multipath support for the mobile node and SHOULD also echo the MAG Multipath Binding option and the MAG NAI option in the corresponding PBA message. 5. IANA Considerations This document requires the following IANA actions. o Action-1: This specification defines a new mobility option, the MAG Multipath-Binding option. The format of this option is described in Section 4.1. The type value <IANA-1> for this mobility option needs to be allocated from the Mobility Options registry at <http://www.iana.org/assignments/mobility-parameters>. RFC Editor: Please replace <IANA-1> in Section 4.1 with the assigned value and update this section accordingly. o Action-2: This specification defines a new mobility option, the MAG Identifier option. The format of this option is described in Section 4.2. The type value <IANA-2> for this mobility option needs to be allocated from the Mobility Options registry at <http://www.iana.org/assignments/mobility-parameters>. RFC Editor: Please replace <IANA-2> in Section 4.2 with the assigned value and update this section accordingly. o Action-3: This document defines a new status value, CANNOT_SUPPORT_MULTIPATH_BINDING (<IANA-3>) for use in Proxy Binding Acknowledgement message, as described in Section 4.3. This value is to be assigned from the "Status Codes" registry at <http://www.iana.org/assignments/mobility-parameters>. The allocated value has to be greater than 127. RFC Editor: Please replace<IANA-4><IANA-3> in Section 4.3 with the assigned value and update this section accordingly. 6. Security Considerations This specification allows a mobile access gateway to establish multiple Proxy Mobile IPv6 tunnels with a local mobility anchor, by registering a care-of address for each of its connected access networks. This essentially allows the mobile node's IP traffic to be routed through any of the tunnel paths based on the negotiated flow policy. This new capability has no impact on the protocol security. Furthermore, this specification defines two new mobility header options, MAG Multipath-Binding option and the MAG Identifier option. These options are carried like any other mobility header option as specified in [RFC5213]. Therefore, it inherits security guidelines from [RFC5213]. Thus, this specification does not weaken the security of Proxy Mobile IPv6 Protocol, and does not introduce any new security vulnerabilities. 7. Acknowledgements The authors of this draft would like to acknowledge the discussions and feedback on this topic from the members of the DMM working group. The authors would also like to thank Jouni Korhonen, Jong Hyouk Lee, Dirk Von-Hugo, Seil Jeon, CarlosBernardos andBernardos, RobertSparksSparks, Adam Roach, Kathleen Moriarty, Hilarie Orman, Ben Campbell, Warren Kumari, Mirja Kuehlewind, for their review feedback. 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/ RFC2119, March 1997,<http://www.rfc-editor.org/info/rfc2119>.<https://www.rfc-editor.org/info/rfc2119>. [RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. Thubert, "Network Mobility (NEMO) Basic Support Protocol", RFC 3963, DOI 10.17487/RFC3963, January 2005,<http://www.rfc-editor.org/info/rfc3963>.<https://www.rfc-editor.org/info/rfc3963>. [RFC5094] Devarapalli, V., Patel, A., and K. Leung, "Mobile IPv6 Vendor Specific Option", RFC 5094, DOI 10.17487/RFC5094, December 2007,<http://www.rfc-editor.org/info/rfc5094>.<https://www.rfc-editor.org/info/rfc5094>. [RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V., Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", RFC 5213, DOI 10.17487/RFC5213, August 2008,<http://www.rfc-editor.org/info/rfc5213>.<https://www.rfc-editor.org/info/rfc5213>. [RFC5648] Wakikawa, R., Ed., Devarapalli, V., Tsirtsis, G., Ernst, T., and K. Nagami, "Multiple Care-of Addresses Registration", RFC 5648, DOI 10.17487/RFC5648, October 2009,<http://www.rfc-editor.org/info/rfc5648>.<https://www.rfc-editor.org/info/rfc5648>. [RFC5844] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy Mobile IPv6", RFC 5844, DOI 10.17487/RFC5844, May 2010,<http://www.rfc-editor.org/info/rfc5844>.<https://www.rfc-editor.org/info/rfc5844>. [RFC5845] Muhanna, A., Khalil, M., Gundavelli, S., and K. Leung, "Generic Routing Encapsulation (GRE) Key Option for Proxy Mobile IPv6", RFC 5845, DOI 10.17487/RFC5845, June 2010,<http://www.rfc-editor.org/info/rfc5845>.<https://www.rfc-editor.org/info/rfc5845>. [RFC6088] Tsirtsis, G., Giarreta, G., Soliman, H., and N. Montavont, "Traffic Selectors for Flow Bindings", RFC 6088, DOI 10.17487/RFC6088, January 2011,<http://www.rfc-editor.org/info/rfc6088>.<https://www.rfc-editor.org/info/rfc6088>. [RFC6089] Tsirtsis, G., Soliman, H., Montavont, N., Giaretta, G., and K. Kuladinithi, "Flow Bindings in Mobile IPv6 and Network Mobility (NEMO) Basic Support", RFC 6089, DOI 10.17487/RFC6089, January 2011,<http://www.rfc-editor.org/info/rfc6089>.<https://www.rfc-editor.org/info/rfc6089>. [RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July 2011,<http://www.rfc-editor.org/info/rfc6275>.<https://www.rfc-editor.org/info/rfc6275>. [RFC7148] Zhou, X., Korhonen, J., Williams, C., Gundavelli, S., and CJ. Bernardos, "Prefix Delegation Support for Proxy Mobile IPv6", RFC 7148, DOI 10.17487/RFC7148, March 2014,<http://www.rfc-editor.org/info/rfc7148>.<https://www.rfc-editor.org/info/rfc7148>. 8.2. Informative References [RFC2473] Conta, A. and S. Deering, "Generic Packet Tunneling in IPv6 Specification", RFC 2473, DOI 10.17487/RFC2473, December 1998,<http://www.rfc-editor.org/info/rfc2473>.<https://www.rfc-editor.org/info/rfc2473>. [RFC4213] Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms for IPv6 Hosts and Routers", RFC 4213, DOI 10.17487/ RFC4213, October 2005,<http://www.rfc-editor.org/info/rfc4213>.<https://www.rfc-editor.org/info/rfc4213>. [RFC4908] Nagami, K., Uda, S., Ogashiwa, N., Esaki, H., Wakikawa, R., and H. Ohnishi, "Multi-homing for small scale fixed network Using Mobile IP and NEMO", RFC 4908, DOI 10.17487/ RFC4908, June 2007,<http://www.rfc-editor.org/info/rfc4908>.<https://www.rfc-editor.org/info/rfc4908>. Authors' Addresses Pierrick Seite Orange 4, rue du Clos Courtel, BP 91226 Cesson-Sevigne 35512 France Email: pierrick.seite@orange.com Alper Yegin Actility Turkey Email: alper.yegin@actility.com Sri Gundavelli Cisco 170 West Tasman Drive San Jose, CA 95134 USA Email: sgundave@cisco.com