MAG Multipath Binding Option
The information below is for an old version of the document.
This is an older version of an Internet-Draft that was ultimately published as RFC 8278.
|Authors||Pierrick Seite , Alper E. Yegin , Sri Gundavelli|
|RFC stream||Internet Engineering Task Force (IETF)|
GENART Telechat review (of -04) by Robert Sparks Ready w/nits
INTDIR Early review (of -02) by Sheng Jiang Almost ready
|Additional resources||Mailing list discussion|
|Stream||WG state||WG Document|
|IESG||IESG state||I-D Exists|
|Send notices to||(None)|
DMM WG P. Seite Internet-Draft Orange Intended status: Standards Track A. Yegin Expires: June 18, 2016 Samsung S. Gundavelli Cisco December 16, 2015 MAG Multipath Binding Option draft-ietf-dmm-mag-multihoming-00.txt Abstract The document [RFC4908] proposes to rely on multiple Care-of Addresses (CoAs) capabilities of Mobile IP [RFC6275] an Network Mobility (NEMO; [RFC3963]) to enable Multihoming technology for Small-Scale Fixed Networks. In the continuation of [RFC4908], this document specifies a multiple proxy Care-of Addresses (pCoAs) extension for Proxy Mobile IPv6 [RFC5213]. This extension allows a multihomed Mobile Access Gateway (MAG) to register more than one proxy care-of-address to the Local Mobility Anchor (LMA). 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. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on June 18, 2016. Copyright Notice Copyright (c) 2015 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of Seite, et al. Expires June 18, 2016 [Page 1] Internet-Draft MAG Multipath Binding Option December 2015 publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. 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 . . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Example Call Flow . . . . . . . . . . . . . . . . . . . . 5 3.2. Traffic distribution schemes . . . . . . . . . . . . . . . 6 4. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . 7 4.1. MAG Multipath-Binding Option . . . . . . . . . . . . . . . 7 4.2. MAG Identifier Option . . . . . . . . . . . . . . . . . . 9 4.3. New Status Code for Proxy Binding Acknowledgement . . . . 10 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8.1. Normative References . . . . . . . . . . . . . . . . . . . 11 8.2. Informative References . . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12 Seite, et al. Expires June 18, 2016 [Page 2] Internet-Draft MAG Multipath Binding Option December 2015 1. Introduction Using several links, the multihoming technology can improve connectivity availability and quality of communications; the goals and benefits of multihoming are as follows: 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 was introducing the concept of multiple Care-of Addresses (CoAs) [RFC5648] that have been specified since then. In the continuation of [RFC4908], a Proxy Mobile IPv6 [RFC5213] based multihomed achitecture could be defined. The motivation to update [RFC4908] with proxy Mobile IPv6 is to leverage on latest mobility working group achievments, namely: 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]. 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. Seite, et al. Expires June 18, 2016 [Page 3] Internet-Draft MAG Multipath Binding Option December 2015 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 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, tunnel can be used at the same time. This document overcome 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: Seite, et al. Expires June 18, 2016 [Page 4] Internet-Draft MAG Multipath Binding Option December 2015 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 MAG functionality. A logical-NAI with ALWAYS-ON configuration is enabled on the MAG. The mobility session that is created on the LMA is for the logical-NAI. The IP hosts MN_1 and MN_2 are assigned IP addresses from the delegated mobile network prefix. +=====+ +=====+ +=====+ +=====+ +=====+ +=====+ | MN_1| | MN_2| | MAG | | WLAN| | LTE | | LMA | +=====+ +=====+ +=====+ +=====+ +=====+ +=====+ | | | | | | | | | | | | | | | (1) ATTACH | | | | | | <--------> | | | | | | (2) ATTACH | | | | | <---------------------->| | | | | (3) PBU (NAI, MAG-NAI, DMNP, MMB) | | | | ------------------------*----------> | | | | (4) PBA (NAI, DMNP) | | | | <-----------------------*----------- | | | | (5) TUNNEL INTERFACE CREATION | | | |-============== TUNNEL ==*===========-| | | | | | | | (6) PBU (NAI, MAG-NAI, DMNP, MMB) | | | | -----------*-----------------------> | | | | (7) PBA (NAI, DMNP) | | | | <----------*------------------------ | | | | (8) TUNNEL INTERFACE CREATION | | | |-===========*== TUNNEL ==============-| | (9) | | | <------------------> | | | | (10) | | | |<-----------> | | Figure 2: Functional Separation of the Control and User Plane Seite, et al. Expires June 18, 2016 [Page 5] Internet-Draft MAG Multipath Binding Option December 2015 3.2. Traffic distribution schemes IP mobility protocols allow to establish the forwarding plane over the WAN interfaces of a multihomed MAG. Then, traffic distribution schemes define the way to distribute data packets over these paths (i.e. IP tunnels). Traffic distribution can be managed either on a per-flow or on a per-packet basis: o per-flow traffic management: each IP flow (both upstream and downstream) is mapped to a given mobile IP tunnel, corresponding to a given WAN interface. This scenario is based on IP flow mobility mechanism using the Flow binding extension [RFC6089]. The mobility anchor provides IP session continuity when an IP flow is moved from one WAN interfaces to another. The flow binding extension allows the IP mobility anchor and the MAG to exchange, and synchronize, IP flow management policies (i.e. policy routing rules associating traffic selectors [RFC6088] to mobility bindings). o Per-packet management: distribute the IP packets of a same IP flow, or of a group of IP flows, over more than one WAN interface. In this scenario, traffic management slightly differs from the default mobile IP behaviour; the mobility entities (mobility anchor and client) distribute packets, belonging to a same IP flow, over more than one bindings simultaneously. The definition of control algorithm of a Per-packet distribution scheme (how to distribute packets) is out the scope of this document. When operating at the packet level, traffic distribution scheme may introduce packet latency and out-of-order delivery. It may require the mobility entities (MAG and mobility anchor) to be able to reorder (ans thus, to buffer) received packets before delivering. A possible implementation is to use GRE as mobile tunnelling mechanism, together with the GRE KEY option [RFC5845] to add sequence number to GRE packets, and so, to allow the receiver to perform reordering. However, more detailed buffering and reordering considerations are out of the scope of this document. The traffic distribution scheme may require the MAG and the to exchange interface metrics to make traffic steering decision.For example, the MAG may send it link bandwidth to the mobility anchor, so that the latter can make traffic forwarding decision accordingly. In this case, the vendor specific mobility option [RFC5094] can be used for that purpose. Per-flow and per-packet distribution schemes are not exclusive mechanisms; they can cohabit in the same multi-access system. For example, High throughput services (e.g. video streaming) may benefit Seite, et al. Expires June 18, 2016 [Page 6] Internet-Draft MAG Multipath Binding Option December 2015 from per-packet distribution scheme, while some other may not. Typically VoIP application are sensitive to latency and thus should not be split over different WAN paths. In this situation, the mobility entities (MAG and mobility anchor) must exchange traffic management policies to associate distribution scheme, traffic and WAN interface (physical or virtual). [RFC6088] and [RFC6089] define traffic management on a flow basis but there is no such policy on a per packet basis. 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. Seite, et al. Expires June 18, 2016 [Page 7] Internet-Draft MAG Multipath Binding Option December 2015 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]. This 8-bit field represents the interface label represented as an unsigned integer. The mobile node identifies the label for each of the interfaces through which it registers a CoA with the home agent. When using static traffic flow policies on the mobile node and the home agent, the label can be used for generating forwarding policies. For example, the operator may have policy which binds traffic for Application "X" needs to interface with Label "Y". When a registration through an interface matching Label "Y" gets activated, the home agent and the mobile node can dynamically generate a forwarding policy for forwarding traffic for Application "X" through mobile IP tunnel matching Label "Y". Both the home agent and the mobile node can route the Application-X traffic through that interface. The permitted values for If-Label are 1 through 255. This 8-bit field is used for carrying the binding identifier. It uniquely identifies a specific binding of the mobile node, to which this request can be associated. Each binding identifier is represented as an unsigned integer. The permitted values are 1 through 254. The BID value of 0 and 255 are reserved. The mobile access gateway assigns a unique value for each of its interfaces and includes them in the message. 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) flag is set to a value of (1). 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. Seite, et al. Expires June 18, 2016 [Page 8] Internet-Draft MAG Multipath Binding Option December 2015 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. Seite, et al. Expires June 18, 2016 [Page 9] Internet-Draft MAG Multipath Binding Option December 2015 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. CANNOT_SUPPORT_MULTIPATH_BINDING (Cannot Support Multipath Binding): <IANA-4> 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-4: This document defines a new status value, CANNOT_SUPPORT_MULTIPATH_BINDING (<IANA-4>) 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> 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 and either based on a static or a dynamically negotiated flow policy. This new capability has no impact on the protocol security. Furthermore, this specification Seite, et al. Expires June 18, 2016 [Page 10] Internet-Draft MAG Multipath Binding Option December 2015 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. 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>. [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>. [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>. [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>. [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>. [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>. [RFC5845] Muhanna, A., Khalil, M., Gundavelli, S., and K. Leung, "Generic Routing Encapsulation (GRE) Key Option for Proxy Seite, et al. Expires June 18, 2016 [Page 11] Internet-Draft MAG Multipath Binding Option December 2015 Mobile IPv6", RFC 5845, DOI 10.17487/RFC5845, June 2010, <http://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>. [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>. [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>. [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>. 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>. [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>. [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>. Seite, et al. Expires June 18, 2016 [Page 12] Internet-Draft MAG Multipath Binding Option December 2015 Authors' Addresses Pierrick Seite Orange 4, rue du Clos Courtel, BP 91226 Cesson-Sevigne 35512 France Email: firstname.lastname@example.org Alper Yegin Samsung Istanbul Turkey Email: email@example.com Sri Gundavelli Cisco 170 West Tasman Drive San Jose, CA 95134 USA Email: firstname.lastname@example.org Seite, et al. Expires June 18, 2016 [Page 13]