Netext WG S. Krishnan Internet-Draft Ericsson Intended status: Standards Track R. Koodli Expires: November 8, 2012 Cisco Systems P. Loureiro NEC Q. Wu Huawei A. Dutta NIKSUN May 7, 2012 Localized Routing for Proxy Mobile IPv6 draft-ietf-netext-pmip-lr-09 Abstract Proxy Mobile IPv6 (PMIPv6) is a network based mobility management protocol that enables IP mobility for a host without requiring its participation in any mobility-related signaling. PMIPv6 requires all communications to go through the local mobility anchor. As this can be suboptimal, localized routing (LR) allows mobile nodes attached to the same or different mobile access gateways to route traffic by using localized forwarding or a direct tunnel between the gateways. This document proposes initiation, utilization and termination mechanisms for localized routing between mobile access gateways within a proxy mobile IPv6 domain. It defines two new signaling messages, Localized Routing Initiation (LRI) and Local Routing Acknowledgment (LRA), that are used to realize this mechanism. 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 November 8, 2012. Krishnan, et al. Expires November 8, 2012 [Page 1] Internet-Draft PMIPv6 Localized Routing May 2012 Copyright Notice Copyright (c) 2012 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 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 . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Initiation of Localized Routing . . . . . . . . . . . . . . . 5 2.1. MAG behavior . . . . . . . . . . . . . . . . . . . . . . . 5 2.2. LMA behavior . . . . . . . . . . . . . . . . . . . . . . . 5 3. Teardown of Localized Routing . . . . . . . . . . . . . . . . 6 4. Conventions used in this document . . . . . . . . . . . . . . 7 5. Scenario A11: Two MNs attached to the same MAG and LMA . . . . 8 5.1. Handover Considerations . . . . . . . . . . . . . . . . . 10 6. Scenario A21: Two MNs attached to different MAGs but same LMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 6.1. Handover Considerations . . . . . . . . . . . . . . . . . 13 6.2. Tunneling between the MAGs . . . . . . . . . . . . . . . . 13 7. Scenario A12: Two MNs attached to the same MAG with different LMAs . . . . . . . . . . . . . . . . . . . . . . . . 15 7.1. Handover Considerations . . . . . . . . . . . . . . . . . 16 8. Scenario A22: Two MNs attached to different MAGs with different LMAs . . . . . . . . . . . . . . . . . . . . . . . . 17 9. IPv4 support in Localized Routing . . . . . . . . . . . . . . 18 10. Message Formats . . . . . . . . . . . . . . . . . . . . . . . 19 10.1. Localized Routing Initiation (LRI) . . . . . . . . . . . . 19 10.2. Localized Routing Acknowledgment (LRA) . . . . . . . . . . 20 11. New Mobility Option . . . . . . . . . . . . . . . . . . . . . 22 11.1. MAG IPv6 Address . . . . . . . . . . . . . . . . . . . . . 22 12. Configuration Variables . . . . . . . . . . . . . . . . . . . 23 13. Security Considerations . . . . . . . . . . . . . . . . . . . 24 14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 15. Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 16. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27 17. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28 17.1. Normative References . . . . . . . . . . . . . . . . . . . 28 Krishnan, et al. Expires November 8, 2012 [Page 2] Internet-Draft PMIPv6 Localized Routing May 2012 17.2. Informative References . . . . . . . . . . . . . . . . . . 28 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 29 Krishnan, et al. Expires November 8, 2012 [Page 3] Internet-Draft PMIPv6 Localized Routing May 2012 1. Introduction Proxy Mobile IPv6 [RFC5213] describes the protocol operations to maintain reachability and session persistence for a Mobile Node (MN) without the explicit participation from the MN in signaling operations at the Internet Protocol (IP) layer. In order to facilitate such network-based mobility, the PMIPv6 protocol defines a Mobile Access Gateway (MAG), which acts as a proxy for the Mobile IPv6 [RFC6275] signaling, and the Local Mobility Anchor (LMA) which acts similar to a Home Agent. The LMA and the MAG establish a bidirectional tunnel for forwarding all data traffic belonging to the Mobile Nodes. In the case where both endpoints are located in the same PMIPv6 domain, this can be suboptimal and results in higher delay and congestion in the network. Moreover, it increases transport costs and traffic load at the LMA. To overcome these issues, localized routing can be used to allow nodes attached to the same or different MAGs to directly exchange traffic by using localized forwarding or a direct tunnel between the gateways. [RFC6279] defines the problem statement for PMIPv6 localized routing. This document describes a solution for PMIPv6 localized routing between two MNs in the same PMIPv6 domain. The protocol specified here assumes that each MN is attached to a MAG and that each MN's MAG has established a binding for the attached MN at its selected LMA according to [RFC5213]. The protocol builds on the scenarios defined in [RFC6279]. Krishnan, et al. Expires November 8, 2012 [Page 4] Internet-Draft PMIPv6 Localized Routing May 2012 2. Initiation of Localized Routing Since the traffic to be localized passes through both the LMA and the MAGs, it is possible, at least in some scenarios, for either of them to initiate Localized Routing (LR). In order to eliminate ambiguity, the protocol described in this document selects the initiator of the LR based on the following rules. 2.1. MAG behavior The MAG MUST initiate LR if both the communicating MNs are attached to it and the MNs are anchored at different LMAs. The MAG MUST NOT initiate LR in any other case. 2.2. LMA behavior The LMA MUST initiate LR if both the communicating MNs are anchored to it. The LMA MUST NOT initiate LR in any other case. Krishnan, et al. Expires November 8, 2012 [Page 5] Internet-Draft PMIPv6 Localized Routing May 2012 3. Teardown of Localized Routing The use of localized routing is not persistent. Localized routing has a defined lifetime as specified by the initiator, upon the expiry of which, the forwarding MUST revert to using bidirectional tunneling. When localized routing ceases, the corresponding LRE entries MUST be removed. If the initiator of LR wishes to terminate localized routing before the expiry of the lifetime specified in the LRI message, it MUST do so by sending a new LRI message with the lifetime set to zero. Krishnan, et al. Expires November 8, 2012 [Page 6] Internet-Draft PMIPv6 Localized Routing May 2012 4. Conventions used in this document 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 [RFC2119]. This document also uses the terminology defined in Section 2 of [RFC6279]. Krishnan, et al. Expires November 8, 2012 [Page 7] Internet-Draft PMIPv6 Localized Routing May 2012 5. Scenario A11: Two MNs attached to the same MAG and LMA In this scenario, the two Mobile Nodes involved in communication are attached to a single MAG and both are anchored at the same LMA as shown in Figure 1. Internet : | | +-----+ | LMA | +-----+ | | | +-----+ | MAG | +-----+ : : +---+ +---+ |MN1| |MN2| +---+ +---+ Figure 1 The LMA initiates a localized routing session by detecting traffic between two MNs attached to the same MAG. The exact traffic identification mechanism is not specified in this document, and is left open for implementations and specific deployments. An example trigger could be that an application-layer signaling entity detects the possibility of localized routing and notifies the LMA about the two end-points, and the LMA determines that the two end-points are attached to the same MAG. Such a trigger mechanism offers localized routing at the granularity of an individual application session, providing flexibility in usage. It is also possible that one of the mobility entities (LMA or MAG) could decide to initiate localized routing based on configured policy. Please note that a MAG implementing the protocol specified in this specification will not dynamically initiate LR in the same LMA case (i.e. by sending an LRI), but can statically initiate LR based on the EnableMAGLocalRouting configuration variable specified in [RFC5213]. Krishnan, et al. Expires November 8, 2012 [Page 8] Internet-Draft PMIPv6 Localized Routing May 2012 +----+ +----+ +----+ +----+ |MN1 | |MN2 | |MAG1| |LMA | +----+ +----+ +----+ +----+ | | | | | data | data | |<--------------------->|<------------->| | | | | | | data | data | | |<--------->|<------------->| | | | LR decision | | | LRI(Opt1) | | | |<--------------| | | | | | | | LRA(Opt2) | | | |-------------->| | | | | | data | | |<--------------------->| | | | | | | | data | | | |<--------->| | | | | | | | | | Opt1: MN1-ID,MN1-HNP,MN2-ID,MN2-HNP Opt2: U=0,MN1-ID,MN1-HNP,MN2-ID,MN2-HNP where U is the flag defined in Section 9.1 and 9.2. Figure 2 After detecting a possibility for localized routing, the LMA SHOULD construct a Localized Routing Initiation (LRI) message that is used to signal the intent to initiate localized routing and to convey parameters for the same. This is a Mobility Header message and it MUST contain the MN-Identifier and the Home Network Prefix (as Mobility Header options) for each of the MNs involved. The LMA MUST then send the LRI message to the MAG (MAG1) where the two MNs are attached as shown in Figure 2. The MAG (MAG1) MUST verify the attachment status of the two MNs locally by checking the binding cache. The MAG MUST then verify if the EnableMAGLocalRouting flag is set to 1. If it is not, the MAG has not been configured to allow localized routing and it MUST reject the LRI and MUST send an LRA with status code "Localized Routing Not Allowed". Please note that this does not update behavior specified in [RFC5213] but merely implements the LMA enforcement specified in Section 6.10.3. of [RFC5213]. If MAG is configured to allow Krishnan, et al. Expires November 8, 2012 [Page 9] Internet-Draft PMIPv6 Localized Routing May 2012 localized routing it MUST then create Localized Routing Entries (LREs) for each direction of the communication between the two MNs. The exact form of the forwarding entries is left for the implementations to decide; however, they SHOULD contain the Home Network Prefix (HNP) corresponding to the destination IP address and a next-hop identifier (e.g. the layer 2 address of the next hop). These LREs MUST override the Binding Update List(BUL) entries for the specific HNPs identified in the LRI message. Hence all traffic matching the HNPs is forwarded locally. If the MAG is unable to deliver packets using the LREs, it is possible that one of the MNs is no longer attached to the MAG. Hence, the MAG MUST fall back to using the BUL entry, and the LMA MUST forward the received packets using its Binding Cache Entry (BCE). After processing the LRI message the MAG MUST respond with a Local Routing Acknowledgment (LRA) message. This Mobility Header message MUST also include the MN-ID and the HNP for each of the communicating MNs as well as an appropriate Status code indicating the outcome of LRI processing. Status code 0 indicates localized routing was successfully offered by the MAG. Any other value for Status code indicates the reason for the failure to offer localized routing service. When Status code is 0, the LMA sets a flag in the BCE corresponding to the HNPs to record that localized routing is in progress for that HNP. 5.1. Handover Considerations If one of the MNs, say MN1, detaches from the MAG and attaches to another MAG (say nMAG) the localized routing state needs to be re- established. When the LMA receives the PBU from nMAG for MN1, it will see that localized routing is active for MN1. It MUST hence initiate LR at nMAG and update the LR state of MAG. After the handover completes, the localized routing will resemble Scenario A21. The pMAG MUST follow the forwarding rules described in Section 6.10.5 of [RFC5213] and decide that it will no longer perform LR for MN1. Krishnan, et al. Expires November 8, 2012 [Page 10] Internet-Draft PMIPv6 Localized Routing May 2012 6. Scenario A21: Two MNs attached to different MAGs but same LMA The LMA may choose to support local forwarding to mobile nodes attached to two different MAGs within a single PMIPv6 domain. Internet : | | +-----+ | LMA | +-----+ | | +----+-----+ | | +----+ +----+ |MAG1| |MAG2| +----+ +----+ : : +---+ +---+ |MN1| |MN2| +---+ +---+ Figure 3 As earlier, the LMA initiates LR as a response to some trigger mechanism. In this case, however, it MUST send two separate LRI messages to the two MAGs. In addition to the MN-ID and the HNP options, each LRI message MUST contain the IP Address of the counterpart MAG. When the MAG IP Address option is present, each MAG MUST create a local forwarding entry such that the packets for the MN attached to the remote MAG are sent over a tunnel associated with that remote MAG. The tunnel between the MAGs is assumed to be established following the considerations mentioned in Section 6.2. Krishnan, et al. Expires November 8, 2012 [Page 11] Internet-Draft PMIPv6 Localized Routing May 2012 +----+ +----+ +----+ +----+ +----+ |MN1 | |MN2 | |MAG1| |MAG2| |LMA | +----+ +----+ +----+ +----+ +----+ | | | | | | data | data | |<--------------------->|<----------------------->| | | | | | | | data | data | | |<--------------------->|<----------->| | | | | | | | | | | | | | LRI(Opt1) | | | |<------------------------| | | | | | | | | | LRI(Opt2) | | | | |<------------| | | | | | | | | LRA(Opt3) | | | |------------------------>| | | | | | | | | | LRA(Opt4) | | | | |------------>| | | | | | | | | | | | | | | | | data | data | | |<--------------------->|<--------->| | | | | | | | | data | | | |<--------------------->| | | | | | | | | | | | Opt1: MN1-ID,MN1-HNP,MAG2-IPv6-Address Opt2: MN2-ID,MN2-HNP,MAG1-IPv6-Address Opt3: U=0,MN1-ID,MN1-HNP,MAG2-IPv6-Address Opt4: U=0,MN2-ID,MN2-HNP,MAG1-IPv6-Address where U is the flag defined in Section 9.1 and 9.2. Figure 4 In this case, each MAG responds to the LRI with an LRA message. All subsequent packets are routed between the MAGs locally, without traversing the LMA. If one of the MAGs (say MAG1) responds with a successful LRA (Status value is zero) and the other (say MAG2)responds with an error (Status value is non-zero) LR will still be performed in one direction (MN1->MAG1->MAG2->MN2), but the packets Krishnan, et al. Expires November 8, 2012 [Page 12] Internet-Draft PMIPv6 Localized Routing May 2012 flowing the other way will take the LMA path (MN2->MAG2->LMA->MAG1->MN1). The protocol does not require any synchronization between the MAGs before local forwarding begins. Each MAG begins its local forwarding independent of the other. No synchronization between MAGs is required because each MAG initiates LR in one direction. After the LMA instructs MAG1 to initiate LR, packets from MN1 to MN2 will take the path MN1->MAG1->MAG2->MN2 while those from MN2 to MN1 will take the path MN2->MAG2->LMA->MAG1->MN1 until LMA instructs MAG2 to do so as well. At any instant a MAG will forward a packet either towards another MAG or its own LMA and hence there would be no duplication of packets. 6.1. Handover Considerations If one of the MNs, say MN1, detaches from its current MAG (in this case MAG1) and attaches to another MAG (say nMAG1) the localized routing state needs to be re-established. When the LMA receives the PBU from nMAG1 for MN1, it will see that localized routing is active for MN1. The LMA MUST then initiate LR at nMAG1 and update the LR state of MAG2 to use nMAG1 instead of MAG1. 6.2. Tunneling between the MAGs In order to support localized routing both MAGs SHOULD support the following encapsulation modes for the user packets, which are also defined for the tunnel between the LMA and MAG: o IPv4-or-IPv6-over-IPv6 [RFC5844] o IPv4-or-IPv6-over-IPv4 [RFC5844] o IPv4-or-IPv6-over-IPv4-UDP [RFC5844] o TLV-header UDP tunneling [RFC5845] o Generic Routing Encapsulation (GRE) tunneling with or without GRE key(s) [RFC5845] MAG1 and the MAG2 MUST use the same tunneling mechanism for the data traffic tunneled between them. The encapsulation mode to be employed SHOULD be configurable. It is RECOMMENDED that: 1. As the default behavior, the inter-MAG tunnel uses the same encapsulation mechanism as that being used for the PMIPv6 tunnel between the LMA and the MAGs. MAG1 and MAG2 automatically start Krishnan, et al. Expires November 8, 2012 [Page 13] Internet-Draft PMIPv6 Localized Routing May 2012 using the same encapsulation mechanism without a need for a special configuration on the MAGs or a dynamic tunneling mechanism negotiation between them. 2. Configuration on the MAGs can override the default mechanism specified in Option 1 above. MAG1 and MAG2 MUST be configured with the same mechanism, and this configuration is most likely to be uniform throughout the PMIPv6 domain. If the packets on the PMIPv6 tunnel cannot be uniquely mapped on to the configured inter-MAG tunnel, this scenario is not applicable, and Option 3 below SHOULD directly be applied. 3. An implicit or explicit tunnel negotiation mechanism between the MAGs can override the default mechanism specified in Option 1 above. The employed tunnel negotiation mechanism is outside the scope of this document. Krishnan, et al. Expires November 8, 2012 [Page 14] Internet-Draft PMIPv6 Localized Routing May 2012 7. Scenario A12: Two MNs attached to the same MAG with different LMAs In this scenario, both the MNs are attached to the same MAG, but are anchored at two different LMAs. MN1 is anchored at LMA1 and MN2 is anchored at LMA2. Note that the two LMAs are part of the same Provider Domain. Internet : : +------------------+ | | +----+ +----+ |LMA1| |LMA2| +----+ +----+ | | | | +------------------+ | | | +-----+ | MAG | +-----+ : : +---+ +---+ |MN1| |MN2| +---+ +---+ Figure 5 Hence, neither LMA has a means to determine that the two Mobile Nodes are attached to the same MAG. Only the MAG can possibly determine that the two Mobile Nodes involved in communication are attached to it. Therefore, the localized routing MUST be initiated by the MAG. The MAG sends an LRI message containing the MN-ID, HNP and the counterpart LMA address to each LMA. Each LMA makes decision to support local forwarding independently, based on, among others, policy configuration for the counterpart LMA. Each LMA MUST respond to the LRI message with an LRA message. If the initiation of LR on the LMA was successful, the Status value in the received LRA would be set to zero. After the MAG receives both the LRA messages each with Status value set to zero (success) from the two different LMAs, the MAG will conclude that it can provide local forwarding support for the two Mobile Nodes. Krishnan, et al. Expires November 8, 2012 [Page 15] Internet-Draft PMIPv6 Localized Routing May 2012 +----+ +----+ +----+ +----+ +----+ |MN1 | |MN2 | |MAG | |LMA1| |LMA2| +----+ +----+ +----+ +----+ +----+ | | | | | | data | data | data | |<--------------------->|<--------->|<----------->| | | | | | | | data | data | | |<--------->|<----------------------->| | | | | | | | | | | | | | LRI(Opt1) | | | | |---------->| | | | | | | | | | LRI(Opt2) | | | |------------------------>| | | | | | | | | LRA(Opt3) | | | | |<----------| | | | | | | | | | LRA(Opt4) | | | |<------------------------| | | | | | | | | | | | | | | | | data | | | |<--------------------->| | | | | | | | | | data | | | | |<--------->| | | | | | | | | | | | | Opt1: MN1-ID,MN1-HNP Opt2: MN2-ID,MN2-HNP Opt3: U=0,MN1-ID,MN1-HNP Opt4: U=0,MN2-ID,MN2-HNP where U is the flag defined in Section 9.1 and 9.2. Figure 6 7.1. Handover Considerations If one of the MNs, say MN1, detaches from its current MAG (in this case MAG1) and attaches to another MAG (say nMAG1), the current MAG MUST immediately stop using the LRE and MUST send all packets originated by the other MN (MN2) towards its LMA (in this case LMA2). Krishnan, et al. Expires November 8, 2012 [Page 16] Internet-Draft PMIPv6 Localized Routing May 2012 8. Scenario A22: Two MNs attached to different MAGs with different LMAs This scenario will not be covered in this document since PMIPv6 does not define any form of inter-LMA communications. When a supported scenario, such as Scenario A12, morphs into Scenario A22 the node that initiated the localized routing session MUST tear it down in order to prevent lasting packet loss. This can result in transient packet loss when routing switches between the localized path into the normal path through the LMAs. In applications that are loss sensitive, this can lead to observable service disruptions. In deployments where Scenario A22 is possible, the use of localized routing is NOT RECOMMENDED when packet-loss-sensitive applications are in use. Krishnan, et al. Expires November 8, 2012 [Page 17] Internet-Draft PMIPv6 Localized Routing May 2012 9. IPv4 support in Localized Routing PMIPv6 MNs can use an IPv4 HoA as described in [RFC5844]. In order to support the setup and maintenance of localized routes for these IPv4 HoAs in PMIPv6, MAGs MUST add the IPv4 HoAs into their LREs. The MAGs MUST also support encapsulation of IPv4 packets as described in [RFC5844]. The localized routing protocol messages MUST include a IPv4 HoA option in their signaling messages in order to support IPv4 addresses for localized routing. If the transport network between the PMIPv6 entities involved in localized routing is IPv4-only, the LRI and LRA messages MUST be encapsulated similar to the PBU/PBA messages as specified in [RFC5844]. The encapsulation mode used SHOULD be identical to the one used to transport PBU and PBA messages. Krishnan, et al. Expires November 8, 2012 [Page 18] Internet-Draft PMIPv6 Localized Routing May 2012 10. Message Formats The Localized routing messages use two new mobility header type (TBA1 and TBA2). The LRI message requests creation or deletion of localized routing state and the LRA message acknowledges the creation or deletion of such localized routing state. 10.1. Localized Routing Initiation (LRI) The LRI messages uses a new mobility header type (TBA1). The LMA sends an LRI message to a MAG to request local forwarding for a pair of MNs. The MAG may also send this message to request the two LMAs for offering local forwarding as described in Section 7 . 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence # | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . . . Mobility options . . . | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Sequence Number: A monotonically increasing integer. Set by a sending node in a request message, and used to match a reply to the request. Reserved: This field is unused. MUST be set zero. Lifetime: The requested time in seconds for which the sender wishes to have local forwarding. A value of 0xffff (all ones) indicates an infinite lifetime. When set to 0, indicates a request to stop localized routing. Mobility Options: MUST contain two separate MN-ID options, followed by one or more HNPs for each of the MNs. For instance, for Mobile Nodes MN1 and MN2 with identifiers MN1-ID, MN2-ID and Home Network Prefixes MN1-HNP and MN2-HNP, the following tuple in the following order MUST be present: [MN1-ID, MN1-HNP], [MN2-ID, MN2-HNP]. The MN-ID and HNP options are the same as in [RFC5213]. MAY contain the remote MAG IPv6 address option, which is formatted identically to the HNP option, except that it uses a different Type code and the Prefix Length is always equal Krishnan, et al. Expires November 8, 2012 [Page 19] Internet-Draft PMIPv6 Localized Routing May 2012 to 128 bits (see Section 10.1). The LRI message SHOULD be re-transmitted if a corresponding LRA message is not received within LRA_WAIT_TIME time units, up to a maximum of LRI_RETRIES, each separated by LRA_WAIT_TIME time units. 10.2. Localized Routing Acknowledgment (LRA) The LRA messages uses a new mobility header type (TBA2). A MAG sends an LRA message to the LMA as a response to the LRI message. An LMA may also send this message to a MAG as a response to the LRI message as described in Section 7 . Krishnan, et al. Expires November 8, 2012 [Page 20] Internet-Draft PMIPv6 Localized Routing May 2012 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence # | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |U| Reserved | Status | Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . . . Mobility options . . . | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Sequence Number: is copied from the sequence number field of the LRI message being responded to. 'U' flag: When set to 1, the LRA message is sent unsolicited. The Lifetime field indicates a new requested value. The MAG MUST wait for the regular LRI message to confirm that the request is acceptable to the LMA. Reserved: This field is unused. MUST be set zero. Status: 0: Success 128: Localized Routing Not Allowed 129: MN not attached Lifetime: The time in seconds for which the local forwarding is supported. Typically copied from the corresponding field in the LRI message. Mobility Options: When Status code is 0, MUST contain the [MN-ID, HNP] tuples in the same order as in the LRI message. When Status code is not 0, MUST contain only those [MN-ID, HNP] tuples for which local forwarding is supported. The MN-ID and HNP options are the same as in [RFC5213]. Krishnan, et al. Expires November 8, 2012 [Page 21] Internet-Draft PMIPv6 Localized Routing May 2012 11. New Mobility Option 11.1. MAG IPv6 Address The MAG IPv6 address mobility option contains the IPv6 address of a MAG involved in the localized routing. The MAG IPv6 address option has an alignment requirement of 8n+4. 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 | Reserved | Address Length| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + MAG IPv6 Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type TBA3 Length 8-bit unsigned integer indicating the length of the option in octets, excluding the type and length fields. This field MUST be set to 18. Reserved (R) This 8-bit field is unused for now. The value MUST be initialized to 0 by the sender and MUST be ignored by the receiver. Address Length This field MUST be set to 128. MAG IPv6 Address A 16 byte field containing the MAG's IPv6 Address. Krishnan, et al. Expires November 8, 2012 [Page 22] Internet-Draft PMIPv6 Localized Routing May 2012 12. Configuration Variables The LMA and the MAG must allow the following variables to be configurable. LRA_WAIT_TIME: This variable is used to set the time interval in seconds between successive retransmissions of an LRI message. The default value is 3 seconds. LRI_RETRIES: This variable indicates the maximum number of times the initiator retransmits an LRI message before stopping. The default value for this variable is 3. Krishnan, et al. Expires November 8, 2012 [Page 23] Internet-Draft PMIPv6 Localized Routing May 2012 13. Security Considerations The protocol inherits the the threats to [RFC5213] that are identified in [RFC4832]. The protocol specified in this document uses the same security association as defined in [RFC5213] for use between the LMA and the MAG to protect the LRI and LRA messages. This document also assumes the pre-existence of a MAG-MAG security association if LR needs to be supported between them. Support for integrity protection using IPsec is REQUIRED, but support for confidentiality is OPTIONAL. The MAGs MUST perform ingress filtering on the MN sourced packets before encapsulating them into MAG-MAG tunnels in order to prevent address spoofing. Krishnan, et al. Expires November 8, 2012 [Page 24] Internet-Draft PMIPv6 Localized Routing May 2012 14. IANA Considerations The Localized Routing Initiation, described in Section 10.1 and the Localized Routing Acknowledgment, described in Section 10.2 each require a Mobility Header Type (TBA1 and TBA2) from the Mobility Header Types registry at http://www.iana.org/assignments/mobility-parameters The MAG IPv6 Address requires a Mobility Option Type (TBA3) from the Mobility Options registry at http://www.iana.org/assignments/mobility-parameters Krishnan, et al. Expires November 8, 2012 [Page 25] Internet-Draft PMIPv6 Localized Routing May 2012 15. Authors This draft merges ideas from five different drafts addressing the PMIP localized routing problem. The authors of these drafts are listed below (in alphabetical order) Kuntal Chowdhury Ashutosh Dutta Rajeev Koodli Suresh Krishnan Marco Liebsch Paulo Loureiro Desire Oulai Behcet Sarikaya Qin Wu Hidetoshi Yokota Krishnan, et al. Expires November 8, 2012 [Page 26] Internet-Draft PMIPv6 Localized Routing May 2012 16. Acknowledgments The authors would like to thank Sri Gundavelli, Julien Abeille, Tom Taylor, Kent Leung, Mohana Jeyatharan, Jouni Korhonen, Glen Zorn, Ahmad Muhanna, Zoltan Turanyi, Dirk von Hugo, Pete McCann, Xiansong Cui, Carlos Bernardos, Basavaraj Patil, Jari Arkko, Mary Barnes, Les Ginsberg, Russ Housley, Carl Wallace, Ralph Droms and Adrian Farrel for their comments and suggestions. Krishnan, et al. Expires November 8, 2012 [Page 27] Internet-Draft PMIPv6 Localized Routing May 2012 17. References 17.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008. [RFC5844] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy Mobile IPv6", RFC 5844, May 2010. [RFC5845] Muhanna, A., Khalil, M., Gundavelli, S., and K. Leung, "Generic Routing Encapsulation (GRE) Key Option for Proxy Mobile IPv6", RFC 5845, June 2010. [RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support in IPv6", RFC 6275, July 2011. 17.2. Informative References [RFC4832] Vogt, C. and J. Kempf, "Security Threats to Network-Based Localized Mobility Management (NETLMM)", RFC 4832, April 2007. [RFC6279] Liebsch, M., Jeong, S., and Q. Wu, "Proxy Mobile IPv6 (PMIPv6) Localized Routing Problem Statement", RFC 6279, June 2011. Krishnan, et al. Expires November 8, 2012 [Page 28] Internet-Draft PMIPv6 Localized Routing May 2012 Authors' Addresses Suresh Krishnan Ericsson 8400 Blvd Decarie Town of Mount Royal, Quebec Canada Phone: +1 514 345 7900 x42871 Email: suresh.krishnan@ericsson.com Rajeev Koodli Cisco Systems Email: rkoodli@cisco.com Paulo Loureiro NEC Email: paulo.loureiro@nw.neclab.eu Qin Wu Huawei Email: Sunseawq@huawei.com Ashutosh Dutta NIKSUN Email: adutta@niksun.com Krishnan, et al. Expires November 8, 2012 [Page 29]