Network Working Group Q.Wu B.Sarikaya Internet Draft Huawei Intended status: Standard Track October 26, 2009 Expires: April 2010 Proxy MIP extension for local routing optimization draft-wu-netext-local-ro-04.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This Internet-Draft will expire on April 26, 2009. Copyright Notice Copyright (c) 2009 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 in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Wu,et al. Expires April 26, 2010 [Page 1] Internet-Draft Proxy MIP Extension for local routing October 2009 Abstract This document extends local routing in proxy Mobile IPv6 and defines a localized routing optimization protocol within one PMIPv6 domain. The protocol supports IPv4 transport network operation, IPv4 home address mobility and handover. The Local mobility anchor/mobile access gateway initiates local routing for the mobile and correspondent node by sending messages to each mobile access gateway/local mobility anchor. In case the correspondent node is connected to another local mobility anchor, the local mobility anchors connected by the correspondent node needs to be discovered firstly so that it can notify its mobile access gateways attached by the correspondent node to the mobile access gateway attached by the mobile node afterwards. Mobile access gateways create and refresh bindings using proxy binding update and acknowledgement messages. Table of Contents 1. Introduction.................................................3 2. Conventions used in this document............................4 3. Scenarios analysis for PMIP6 local routing...................5 4. Local routing optimization protocol overview.................6 4.1. MAG initiated local routing optimization................6 4.1.1. Handover Consideration.............................8 4.2. LMA initiated local routing optimization................9 4.2.1. Handover Consideration............................10 5. Process consideration.......................................11 5.1. Mobile Access Gateway Consideration....................11 5.2. Local Mobility Anchor Consideration....................15 6. IPv4 support................................................16 6.1. IPv4 HoA support.......................................16 6.2. IPv4 transport support.................................17 7. Inter-LMA Local routing Consideration.......................17 7.1. MAG Initiated Inter-LMA local routing..................17 8. Conceptual Data Structure Extension.........................18 8.1. Binding Update List Extension..........................18 8.2. Binding Cache Entry Extension..........................19 8.3. Routing Table Entry Extension..........................19 9. Local routing optimization message format...................19 9.1. Local Routing optimization mobility option.............19 9.2. Local Routing optimization Request message(LROREQ).....20 9.3. Local Routing optimization Response Message(LRORSP)....21 9.4. Context Request Option.................................23 Wu,et al. Expires April 26, 2010 [Page 2] Internet-Draft Proxy MIP Extension for local routing October 2009 9.5. MN-CNs pair mobility option...........................23 10. Security Considerations...................................24 11. IANA Considerations.......................................24 12. Acknowledgement...........................................25 13. References................................................25 13.1. Normative References.................................25 13.2. Informative References...............................25 Appendix A Future Extension..................................26 A.1. LMA Route Optimization Start Message.....................26 A.1.1 LMA Route Optimization Start Request Message.........26 A.1.2. LMA Route Optimization Start Response Message.......27 A.2. LMA Initiated Inter-LMA Local Routing....................27 A.2.1 IPv4 Support Consideration...........................29 A.3. LMA Initiated operation for Inter-LMA Local Routing...30 Appendix B Change Notes......................................31 1. Introduction Proxy Mobile IPv6 [RFC5213] can allow the Mobility Access Gateway (MAG) to optimize the media delivery by locally routing the packets within one MAG and by not reverse tunneling them to the mobile node's local mobility anchor (LMA). However it does not address the case of routing optimization between two MAGs sharing the same LMA or registering to the different LMA. The capability for local routing optimization provided in [RFC5213] requires the MAG to support the EnableMAGLocalRouting flag and allow the MAG to control local routing optimization behavior. However, [RFC5213] does not define how local routing optimization capability is detected, who initiates local routing optimization and how to negotiate between the MAG and the LMA to determine whether the local routing optimization is allowed. This document defines a local routing optimization mobility messages or options for proxy mobile ipv6 that is intended to assist the MAGs to negotiate and setup local routing path between each other. The new local routing optimization mobility options included in each binding update or local routing optimization messages exchange is used to negotiate between the LMA and the MAG whether and what local routing is allowed. Different from the local forwarding control message described in the [I-D.LocalFwd], the local routing optimization messages can be initiated by either of pmip6 managed node and provide flexible negotiation mechanism for local routing. As [RFC5213] warns, use of local routing may affect accounting and traffic policies relating to the mobile node, LMA routing policies, and security policies. The general aim of the proposals in this document is to provide better manageability of local routing services and local routing service provisioning from the point of view of both operators and service providers within one PMIPv6 domain. Wu,et al. Expires April 26, 2010 [Page 3] Internet-Draft Proxy MIP Extension for local routing October 2009 2. 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 RFC-2119. The document uses the terminology specified in [RFC5213] and in [RFC3775]. In addition, this document defines the following: Local routing: Traffic between MN and CN does not pass through LMA and is locally routed in the same PMIPv6 domain. Local Routing Optimization Request (LROREQ): A message initiated by the MAG or LMA requesting the MAG or LMA to establish local routing optimization path between MN and at least one pair of CNs who communicate with MN. Local Routing Optimization Response (LRORSP): A reply message from the MAG or LMA to confirm local routing optimization results. Wu,et al. Expires April 26, 2010 [Page 4] Internet-Draft Proxy MIP Extension for local routing October 2009 3. Scenarios analysis for PMIP6 local routing Figure 1 shows the reference architecture for PMIP6 local routing. In this architecture, the local communication between PMIPv6 managed nodes(i.e., MAGs) is constrained within a single PMIPv6 domain. LMA1 and LMA2 which MN and CN are respectively anchored to may be the same LMA or different LMAs in the same PMIPv6 domain. +---------+ ============|LMA1/LMA2|============ // +---------+ \\ || || || || || +-----------+ +-----------+ | IPv4/IPv6 | | IPv4 | | Network | | Network | +-----------+ +-----------+ || || || || +-----------+ || +------+ |IPv4/IPv6 | +------+ | MAG1 |=============================| MAG2 | +------+ | Network | +------+ | | +-----------+ | | +-----+ +-----+ +-----+ +-----+ | | | | +----+ +-----+ +-----+ +-----+ | MN | | CN1 | | CN2 | | CN3 | +----+ +-----+ +-----+ +-----+ {IPv4-MN-HoA1} {IPv4-CN1-HoA2} {IPv4-CN2-HoA3} {IPv6-CN3-HoA4} {IPv6-MN-HoA1} {IPv6-CN2-HoA3} Figure 1: Reference architecture for PMIP6 local routing Depending on how MN and CN are distributed into one PMIP6 domain, three typical scenarios need to be considered as follows: Scenario 1: Intra-MAG local routing In this scenario, MN and CN attach to the same MAG and are anchored with the same LMA or different LMAs. Scenario 2: Intra-LMA local routing In this scenario, MN and CN attach to the different MAGs and are anchored with the same LMA. Scenario 3: Inter-LMA local routing Wu,et al. Expires April 26, 2010 [Page 5] Internet-Draft Proxy MIP Extension for local routing October 2009 In this scenario, MN and CN attach to the different MAGs and are anchored with the different LMAs. In all the above scenarios, MN is allowed to roam within its PMIPv6 domain (i.e, MN's home domain in which MN's LMA is located) or move from one PMIPv6 domains(i.e., MN's visited domains)to another. CN should stay with MN within the same PMIPv6 domain, e.g., MN moves to the visited domain to which CN belongs. Another example is MN and CN move to the same visited domain to which MN's LMA or CN's LMA does not belong. 4. Local routing optimization protocol overview The protocol specified here assumes that o the MAGs are situated in one PMIP domain o MN and CN are anchored with the same LMA. o The MAG has the capability to perceive intra-MAG local routing (i.e., the MAG can detect whether the mobile node and correspondent node attach to the same MAG). o The LMA has the capability to perceive intra-LMA local routing (i.e., the LMA can detect whether the MAGs to which MN and CN are attach belong to the same or different LMAs). The flag EnableDetectLocalRouting on the MAG and LMA may be used to control this behavior. The decision to enable/disable detection of local routing should be based on the policy configured on the MAG or LMA. The specific details on how this is achieved are beyond of the scope of this document. Subsequently depend on who initiate local routing, the local routing optimization can be categorized into two aspects. 4.1. MAG initiated local routing optimization When the EnableDetectLocalRouting is enabled in the MAG, the MAG can start to detect whether the MN and CN attach to the same MAG by checking binding update List of MN and CN. Upon the MAG receives the packet from MN or CN and perceives MN and CN attach to the same MAG, it can initiate local routing optimization to determine the value of the intra-MAG local routing flag (defined in section 8) by message exchange between the MAG and LMA (If the MAG attached by the MN and CN register to the different LMAs, it needs to initiate local routing optimization to the different LMAs Wu,et al. Expires April 26, 2010 [Page 6] Internet-Draft Proxy MIP Extension for local routing October 2009 respectively). When the MAG detect that MN and CN don't attach to the same MAG but want to check whether intra-LMA routing is allowed(i.e., MN and CN attach to different MAGs and register to the same LMA), it also can initiate the local routing optimization by sending message to the LMA. The message may be a binding update message which contains the local routing optimization mobility option and home network prefix option for the correspondent node or a newly defined local routing optimization message. It will be used to negotiate with LMA to determine whether or what the local routing optimization between the mobile node and correspondent node is supported. The AAA server can be used to authorize the use of localized routing service for MN. If the AAA sever does not authorize the use of localized routing service or the LMA does not allow the MAG bypass traffic from itself, LMA will respond to the MAG that the local routing optimization is not available. Otherwise LMA will set the intra-MAG localrouting or intra-LMA localrouting flag on the MAG into value one in the successful response message. After successful local routing optimization process, if MN and CN attach to the different MAGs, i.e., MAG1, MAG2 and intra-LMA localrouting flag is set to value one, the MAG1 to which the MN attaches may send PBU message to the MAG2 which the CN attaches to. The PBU/PBA signaling is protected using IPsec Encapsulation security payload [RFC4303] in transport mode with mandatory integrity protection. This PBU message sets the lifetime of the binding of MN at MAG2. Similarly if intra-LMA localrouting flag is set to value one on the MAG2, the MAG2 sends PBU message to the MAG1. This PBU message sets the lifetime of the binding of CN at MAG1. Each PBU MUST be acknowledged with PBAs. With PBU/PBA exchange, the local data path between MAGs is established and the binding caches associated with MN and CN are set up. Also PBU-PBA exchange is repeated to extend the lifetime of the binding. For the data traffic, either of the MAGs can lookup the routing table entry associated with MN or CN and identify the tunnel to the right MAG in terms of destination address of outgoing data packet. If MN and CN attach to the same MAG, the traffic from MN will go directly to CN via the MAG. If MN and CN attaches to the different MAG and register to the same LMA, the traffic from MN will be forwarded directly by the MAG associated with MN to the MAG associated with the CN. Wu,et al. Expires April 26, 2010 [Page 7] Internet-Draft Proxy MIP Extension for local routing October 2009 +--+ +------+ +-----+ +------+ +--+ |MN| | MAG1 | | LMA | | MAG2 | |CN| ++-+ +--+---+ +--+--+ +--+---+ +-++ Attach to MAG1 | |Attach to MAG2 |---------->| | <------------+ | Datagram | PBU'/LROREQ | | | |==========>|(MN-CN Pair) | | | | |------------->| | | | | +---+-----+ | | | | |BCE Check| | | | PBA'/LRORSP|---------+ | | | | [MAG2] | | | | |<------------ | | | | +-------+---------+ | | | | |Enable Intra-LMA/| | | | | |intra-MAG Routing| | | | | +-------+---------+ | | | | Bidirectional PBU/PBA between MAGs | | |<--------------------------->| | | +-------------+ | +-------------+ | | |Setup Binding| | |Setup Binding| | | |and Tunnel | | | and Tunnel | | | +-------------+ | +-------------+ | | Datagram | Datagram | Datagram | |==========>|============================>|===========>| | Datagram | Datagram | Datagram | |<==========|<=============|==============|<===========| | | | | | | | | | | Figure 2: MAG Initiated Local routing optimization 4.1.1. Handover Consideration In case of handover when the MN moves from the old MAG (e.g., pMAG1) in the previous access network to the new MAG(e.g., nMAG1) in the new access network, registration entry for MN in pMAG1's Binding update list should be transferred to the nMAG1. The context request option defined in the [I-D.ietf-mipshop-pfmipv6] can be reused to carry the context information on pMAG1 to nMAG1. And the new MAG(i.e., nMAG1) sends PBUs to each MAG with which MN was in communication via local route optimization path established. This PBU/PBA exchange updates the binding in each MAG with which MN was in communication and re- establishes optimal local route path between MN and its CNs. Wu,et al. Expires April 26, 2010 [Page 8] Internet-Draft Proxy MIP Extension for local routing October 2009 +-----+ +---------+ +---------+ |pMAG1| |nMAG1(MN)| | MAG2(CN)| +--+--+ +---+-----+ +---+-----+ | | | | HI/HACK | | |<--------------->| | |Predictive/Reactive | | |Bidirectional PBU/PBA| | |<------------------> | | | | | +------+------+ +-----+-------+ | |UpdateBinding| |UpdateBinding| | | and Tunnel | | and Tunnel | | +------+------+ +-----+-------+ | | Datagram | | |<===================>| Figure 3: MAG initiated Local routing during handover 4.2. LMA initiated local routing optimization When the EnableDetectLocalRouting is enabled in the LMA, the LMA can start to detect whether the MN and CN register to the same LMA by checking binding List of MN and CN. Upon receiving the packet from the MN or CN and perceiving MN and CN register to the same LMA, it may correlate MN with CN in one the routing table entry associated with MN and initiate local routing optimization to determine the value of Intra-LMA localrouting flag (defined in section 8)at MAG, i.e., notify or enforce the value of intra-LMA flag to the MAG associated with MN by message exchange between the MAG and LMA. The message could be proxy binding update message which contains local routing optimization mobility option or a newly defined routing optimization message. It will be used to help LMA to determine whether or not the local routing optimization is allowed and enforce the local optimization on the MAG. The AAA server serving LMA can be used to authorize the use of localized routing service for MN. If the AAA sever does not authorize the use of localized routing service or If the LMA verifies there exists binding cache list of correspondent node and mobile node and allow the MAG bypass traffic between mobile node and correspondent node from itself, it will notify the MAG to set the intra-LMA Localrouting flag into value one, otherwise, it will respond to MAG with failure information which indicates the intra-LMA routing optimization is not supported. The other procedures are same as that of section 4.1. Wu,et al. Expires April 26, 2010 [Page 9] Internet-Draft Proxy MIP Extension for local routing October 2009 +--+ +------+ +-----+ +------+ +--+ |MN| | MAG1 | | LMA | | MAG2 | |CN| ++-+ +--+---+ +--+--+ +--+---+ +-++ Attach to MAG1 | |Attach to MAG2 |---------->| +-------+----------+ <------------+ | | | BCE Check | | | | | |Perceive MAG1 and | | | | | |MAG2 register to | | | | | |the same LMA | | | | | +-------+----------+ | | | | LROREQ | | | | | (MAG2) | | | | |<------------ | | | | +-------+---------+ | | | | |Enable Intra-LMA/| | | | | | Routing | | | | | +-------+---------+ | | | | LRORSP | | | | |------------->| | | | Bidirectional PBU/PBA between MAGs | | |<--------------------------->| | | +-------------+ | +-------------+ | | |Setup Binding| | |Setup Binding| | | | and Tunnel | | | and Tunnel | | | +-----+-------+ | +-----+-------+ | | Datagram | Datagram | Datagram | |==========>|============================>|===========>| | Datagram | Datagram | Datagram | |<==========|<============================|<===========| Figure 4: LMA Initiated Local routing optimization 4.2.1. Handover Consideration In case of handover when the MN moves from the old MAG (e.g., pMAG1) in the previous access network to the new MAG(e.g., nMAG1) in the new access network, MAG1 may update the binding cache entry associated with MN at the LMA by sending normal PBU. At the same time, LMA may refresh routing table entries associated with MN as well and update binding of each MAG with which MN was in communication via local route optimization path established by sending LROREQ to each MAG. Also MAG1 can use the similar procedure described in the section 4.1.1 to transfer MN's registration entry at pMAG1 to the new MAG (i.e., nMAG1). Wu,et al. Expires April 26, 2010 [Page 10] Internet-Draft Proxy MIP Extension for local routing October 2009 +-----+ +---------+ +----------+ +---------+ |pMAG1| |nMAG1(MN)| |LMA(MN,CN)| | MAG2(CN)| +--+--+ +---+-----+ +----+-----+ +---+-----+ | | Normal PBU | | | |-------------->| | | | | | | | Normal PBA | | | |<------------- | LROREQ | | | |-------------->| | | | | | | | LRORSP | | | |<------------- | | Bidirectional PBU/PBA between MAGs | |<----------------------------->| | +------+------+ | +-----+-------+ | |UpdateBinding| | |UpdateBinding| | | and Tunnel | | | and Tunnel | | +------+------+ Datagram +-----+-------+ | |<=============================>| | | | | Figure 5: LMA initiated Local routing optimization during handover 5. Process consideration 5.1. Mobile Access Gateway Consideration The MAG may include the routing optimization mobility option and MN- CNs pair mobility option into binding update message or create a new routing optimization request message in which the above two options are contained. The routing optimization mobility option is used to negotiate which kind of local routing optimization is available. The MN-CNs pair mobility option is used for the LMA to verify the validity of local routing optimization path end points (in the intra- MAG local routing scenario) or to request the LMA to determine proxy CoA-Address of correspondent node for local routing optimization (in the intra-LMA local routing scenario). In the intra-MAG local routing case, LRI field in routing optimization mobility option is set into value 1 while in the intra-LMA local routing case, LRI field in routing optimization mobility option is set into value 0, because mobile node's MAG does not know whether traffic between MN and CN can be locally routed within one LMA. When the MAG receives binding acknowledge message with routing optimization mobility option or routing optimization response message, it will check Mobile access gateway check all fields validity in the response/acknowledge message including whether the Wu,et al. Expires April 26, 2010 [Page 11] Internet-Draft Proxy MIP Extension for local routing October 2009 sequence number value in acknowledge/response message is identical to the sequence number value in request message, whether MN-CN pairs mobility option is included in the response/acknowledge message. In successful case, MAG then will extract the LRI field from the routing optimization mobility option or routing optimization response message and check the value of it. If LRI field is 0, it indicates the LMA does not support this local routing optimization and the MAG should set intra-MAG LocalRouting flag to value 0 in the binding update list extension; if LRI field is 1, it indicates the LMA allow local routing in one MAG and bypass the LMA and MAG should set intra-MAG LocalRouting flag to value 1 in the binding update list extension, if LRI field is 2, it indicates LMA has found correspondent node's MAG address in terms of home network prefix of CN and MAG should extract correspondent node's MAG address from initial binding acknowledge message or routing optimization response message and store it in binding update list extension with correspondent node's home network prefix. When MAG receives LROReq message from the LMA for each MN-CN RO Option pair it searches the binding update list for a matching IPv6 home network prefix in the list of prefixes it stores for each mobile node that MAG is serving. If a match is found, MAG MUST send a PBU message to the MAG of the correspondent node. PBU message lifetime is set to the lifetime value in LROReq message. Destination address is the same as Proxy CoA field in CN part of MN- CN pairs mobility Option found in LROReq message. MAG MUST send PBU message to the MAG of each correspondent node if LROReq message contains more than one CN in the MN-CN pairs mobility option. For each PBU message sent to a MAG, a new binding update list entry MUST be created if it has not already been created before, e.g. refresh PBU. The fields in this entry are set as follows: O Mobile node information fields like MN-Identifier, link-layer identifier, home network prefixes, etc. are copied from the existing entry that was created during the initial PBU procedure. O The IPv6 address of the LMA serving the attached mobile node is replaced with Proxy-CoA of the MAG to which the PBU was sent and Proxy-CoA field in correspondent node part of MN-CN RO Option is copied to this field. IP address of the correspondent node to which MN is communicating with is set to Home Network Prefix Wu,et al. Expires April 26, 2010 [Page 12] Internet-Draft Proxy MIP Extension for local routing October 2009 field of the correspondentnode part of MN-CN pair mobility Option. If P bit is set in MN-CN pairs mobility Option, this field is set to IPv4 HoA field of the correspondent node part of MN-CN pairs mobility Option. O The initial value of binding lifetime field is set to the lifetime field of LROReq message. O A configuration variable called EnableLMALocalRouting is defined at the MAGs to indicate whether or not the MAG is allowed to enable local routing of the traffic exchanged between a visiting MN that is locally connected to one of the interfaces of the mobile access gateway and a CN that is locally connected to one of the interfaces of another mobile access gateway that is connected to the same LMA. Any LROReq message received from LMA with lifetime greater than zero enables the local routing at this MAG and the MAG that receives LROReq first time MUST set EnableLMALocalRouting to 1. Upon the intra-MAG Localrouting flag or intra-LMA Localrouting flag setup at the MAGs, one MAG may send the proxy binding update message to another MAG to establish corresponding binding cache associated with the MN and CN. Upon receiving Proxy Binding Update message, the MAG checks if the LocalRouting flag is set to one. If the LocalRouting flag is not set to one, the MAG MUST reject the request and send a Proxy Binding Acknowledgement message with the status field set to 129 (administratively prohibited). Upon accepting Proxy Binding Update request, the MAG MUST create a Binding Cache entry. The Source address of Proxy Binding Update is copied to Proxy CoA field of the binding cache entry. The Mobile node data (MN- Identifier, link-layer identifier, link-local address, home network prefixes, etc.) are copied from the corresponding fields of the proxy binding update. Upon accepting Proxy Binding Update request for the first time from another MAG, the MAG MUST establish a bi-directional tunnel between the two MAGs. The tunnel endpoints are the Proxy-CoA of this mobile access gateway and the Proxy-CoA of the mobile access gateway that sent Proxy Binding Update as can be obtained from the source address of Proxy Binding Update. This tunnel should be deleted when there are no mobile nodes sharing it or when mobile access gateway receives RORQ message from local mobility anchor with lifetime set to zero. Wu,et al. Expires April 26, 2010 [Page 13] Internet-Draft Proxy MIP Extension for local routing October 2009 In case of handover or detachment, if the mobile access gateway cannot predictably detect the presence of the mobile node on the connected link, the MAG SHOULD terminate the binding of the mobile node by sending a PBU message to all CN's MAGs that has established bindings. MAG sends a PBU message to each MAG with lifetime set to zero. Proxy-CoA of the MAG field in each Binding update list entry determines the MAG address. If IPv4 transport is used, IPv4-Proxy- CoA is used. MAG MUST also remove each Binding Update List entry created for that MN. In order to re-establish bindings of the MN that is involved in local routing, i.e. with binding update list entries other than the home (local mobility anchor registration) the previous MAG MAY use context transfer procedure to transfer the local routing state to the new MAG. Each entry in the binding update list for this MN other than the LMA entry can be transferred. After handover is completed, the new MAG MUST send PBU messages to each MAG (Proxy-CoA or IPv4-Proxy-CoA) associated with each correspondent node. For the data traffic between the MN and CN, on receiving a packet from a mobile node connected to its access link, to a destination (i.e.,CN) that is directly connected or not directly connected to the same access link, the MAG will check whether source/destination address pairs in the routing table entry matches the source/destination address in the outgoing data packet and identify the tunnel to the right destined MAG. If the source address and destination address in the packet match one of source/destination addresses pair in the routing entry, the packet must be tunneled to the Proxy CoA corresponding to the destination address in the tunnel interface. For the packet from a mobile node connected to its access link, to a destination that is also directly connected to the same access link, the packet must go directly via the MAG. Wu,et al. Expires April 26, 2010 [Page 14] Internet-Draft Proxy MIP Extension for local routing October 2009 5.2. Local Mobility Anchor Consideration For the case where the MAG initiates local routing, upon receiving binding update message or routing optimization request message, the LMA will check LRI field in the routing optimization mobility option or routing optimization message. If LRI field is set to value one, the LMA will check whether there exist binding cache list for CN and whether MN's proxy CoA address is same as CN's proxy CoA address. If LRI field is 0 and correspondent node's home network prefix included, the LMA will check whether there exists binding cache list for CN in terms of the correspondent node's home network prefix. If does, the LMA will respond to the MAG with LRI field set to value 2. Otherwise, the LMA will respond to the MAG with LRI field set to 0 in the routing optimization mobility option to indicate the MAG that the local routing optimization is not available. For the case where the LMA initiates local routing, LMA may be responsible for perceiving intra-LMA routing and correlate MN with CN in the routing table entry. Upon perceiving intra-LMA routing, the LMA sends routing optimization request message with the LRI field set to value 2. And then the LMA receives routing optimization reply message from the corresponding MAG. LMA MUST send LROReq message to either or both of MAGs where MN and CN are located. If CN (or MN) is not connected to this LMA, the LROReq message MUST be sent to only one MAG. The LROReq message MUST contain at least one pair of MN-CN pairs mobility Option.If MN is communicating with more than one CN which registers to the same LMA, LMA MUST include more than CNs in the MN-CN pairs mobility Option if localized routing will be enabled. When LROReq is sent to a MAG, LMA MUST place the MN address information which is connected to this MAG first in MN-CN pairs mobility Option. LMA MAY set lifetime field in LROReq message to a non zero value. Any nonzero lifetime value enables two MAG to start local routing optimization for MN-CN traffic. The lifetime values sent to two MAG MUST be the same. LMA MAY stop the local routing optimization operation any time it wishes. In that case LMA MUST set lifetime field in LROReq message to zero. After receiving LRORes message from MAG with matching sequence number field, the LMA-MAG tunnel is re-established separately for each MAG. Wu,et al. Expires April 26, 2010 [Page 15] Internet-Draft Proxy MIP Extension for local routing October 2009 LMA sets the sequence number field in LROReq message to a nonzero integer. This initial sequence number is incremented by one for the next LROReq message sent. LMA MUST receive LRORes message with the same sequence number as in LROReq message previously sent. This message is acknowledged with LROReq message. If no ack is received LMA MUST retransmit LROReq message. 6. IPv4 support IPv4 support is needed in two cases: O MN is IPv4 enabled and receives IPv4 home address and O The transport network between the LMA and the MAG is an IPv4 network. In both two cases, the encapsulation mode as described in [I- D.draft-netlmm-pmip6-ipv4-support] are transparent to the MAG concerned before setting up the localized routing path. This may result in data packets are dropped by the egress/ingress tunnel end point, i.e., the MAGs. Therefore local route optimization can be supported only if the encapsulated mode is aware during setting up the localized routing path. 6.1. IPv4 HoA support In case MN is IPv4 enabled and receives IPv4 home address, both the MN and the CN configure global IPv4 home addresses by exchanging PBU/PBA as explained in [I-D.ietf-netlmm-pmip6-ipv4-support] with the LMA. The LMA MUST include IPv4 IPv4-MN-HoA in local routing optimization messages for both MN and CN. The LMA MAY include Home Network Prefix in PBA if the MN or CN is assigned Home Network Prefix. Both local routing optimization request and local routing optimization response messages are IPv6 messages and are transported over LMA-MAG tunnel as PBU and PBA are transported. The PBU and PBA exchanged between the MAGs are IPv6 messages and are transported as unencapsulated IPv6 messages between MAGs. Various encapsulation modes described in the [I-D.ietf-netlmm-pmip6-ipv4- support] can be used in PBU and PBA and encapsulation mode negotiation between the MAGs is required If the MAGs in communication support different encapsulation mode. For Wu,et al. Expires April 26, 2010 [Page 16] Internet-Draft Proxy MIP Extension for local routing October 2009 simplification, we can assume the MAGs in communication are using the default encapsulation mode. Data traffic between the MAGs after local routing is established are transported in IPv6 inner packet as IPv4 payload. 6.2. IPv4 transport support In case IPv4 transport is used between the MAG and the LMA, LROREQ, LRORSP, PBU and PBA messages are transported as IPv6 messages using IPv4 or IPv4-UDP-ESP encapsulation [I-D.ietf-netlmm-pmip6-ipv4- support]. IPv4-UDP and IPv4-UDP-TLV modes are not used because no NAT boxes are supported in this local routing optimization protocol. IPv4 data packets are transported in an IPv4 packet or encapsulated in IPv4-UDP-ESP encapsulation. 7. Inter-LMA Local routing Consideration In this section we concentrate on the local routing case where MN and CN are served by two different LMAs, in the same PMIPv6 domain which is not covered by the section 4. 7.1. MAG Initiated Inter-LMA local routing The message exchange for the protocol is shown in Figure 6. Local routing case is triggered at one of the MAGs, e.g. MAG1 when a datagram is received on its upstream interface whose destination address is a CN for which LMA2 has a binding cache entry. MAG1 request LMA2 address from LMA1 by sending LROREQ message contain CN HNP or HoA to LMA1. LMA1 processes LROREQ message and lookup LMA2 address based on CN HNP or HoA. There are one possible ways to achieve this goal. a. MAG1 can exchange with AAA server to retrieve LMA2 address. MAG1 sends CN address and asks the address of LMA2 which CN is anchored to. The AAA server responds LMA2 address to MAG1. Upon retrieving LMA2 address, MAG1 then sends LROREQ message containing MN-CN pairs defined in the section 9.5 to LMA2. LMA2 process LROREQ message and looks up MAG2 address based on CN HNP or HoA extracted from the corresponding message. In successful case, LMA2 responds to the MAG1 with MAG2 address corresponding to CN. MAG1 and MAG2 exchange PBU/PBA to establish binding cache list between each other and direct path between MAG1 and MAG2 will be setup. Wu,et al. Expires April 26, 2010 [Page 17] Internet-Draft Proxy MIP Extension for local routing October 2009 +------+ +----------+ +---------+ +------+ | MAG1 | | LMA1(MN) | | LMA2(CN)| | MAG2 | +---+--+ +----+-----+ +----+----+ +---+--+ | | | | +----+----+ | | | | LMA2 | | | | |Discovery| | | | +----+----+ | | | | LROREQ(MN,MAG1,CN) | | |------------------------------->| | | LRORSP(CN,MAG2) | | |<-------------------------------| | | | | | |<------------MAGs Exchange PBU/PBA-------------->| | | | | Figure 6: MAG Initiated Inter-LMA Local routing Editor Notes: LMA initiated Inter-LMA local routing is described in the Appendix A for future extension. In the LMA initiated Inter-LMA local routing, LMA-LMA communication is required to setup local routing path. 8. Conceptual Data Structure Extension 8.1. Binding Update List Extension Every mobile access gateway maintains a Binding Update List. Each Entry in the Binding Update List represents a mobile node's mobility binding with its local mobility anchor, as described in Section 6.1 of the PMIPv6 specification [RFC5213]. This specification extends the Binding Update List Entry data structure with the following additional fields: O Intra-MAG LocalRouting Flag indicating whether the media delivery optimization is allowed by locally routing the packets within one MAG. The flag is set to value 1 for local media delivery optimization is allowed and vice versa. O Intra-LMA LocalRouting Flag indicating whether the media delivery optimization is allowed by locally routing the packets from one MAG to another within one LMA. The flag is set to value 1 for local media delivery optimization is allowed and vice versa. O Inter-LMA LocalRouting Flag indicating whether the media delivery optimization is allowed by locally routing the packets from one MAG served by one LMA to another MAG served by the different LMA. Wu,et al. Expires April 26, 2010 [Page 18] Internet-Draft Proxy MIP Extension for local routing October 2009 The flag is set to value 1 for local media delivery optimization is allowed and vice versa. 8.2. Binding Cache Entry Extension Every local mobility anchor MUST maintain a Binding Cache entry for each currently registered mobile node. For supporting this specification, the Binding Cache Entry data structure needs to be extended with the following additional field: O Intra-LMA LocalRouting Flag indicating whether the media delivery optimization is allowed by locally routing the packets from one MAG to another within one LMA. The flag is set to value 1 for local media delivery optimization is allowed and vice versa. O Inter-LMA LocalRouting Flag indicating whether the media delivery optimization is allowed by locally routing the packets from one MAG served by one LMA to another MAG served by the different LMA. The flag is set to value 1 for local media delivery optimization is allowed and vice versa. 8.3. Routing Table Entry Extension Every mobile access gateway and local mobility anchor MUST maintain a Routing Table entry for each currently registered mobile node. O Home Address assigned to correspondent node O Home Address assigned to mobile node O Tunnel interface assigned to the data path between mobile node and correspondent node 9. Local routing optimization message format 9.1. Local Routing optimization mobility option 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 = TBD | Length | Reserved |LRI~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7. Local Routing Optimization Mobility Option Type TBD Wu,et al. Expires April 26, 2010 [Page 19] Internet-Draft Proxy MIP Extension for local routing October 2009 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 2. 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. Local Routing Optimization Indication (LRI) 00: Routing optimization state is unknown or routing optimization is not available. 01: The value of Intra-MAG LocalRouting 10: The value of Intra-LMA LocalRouting 11: The value of Inter-LMA LocalRouting 9.2. Local Routing optimization Request message(LROREQ) The Local Routing optimization Request message is used by one PMIP6 managed node (e.g., LMA or MAG) to negotiate with another PMIP6 managed node(e.g., MAG or LMA) whether and what local routing is allowed. 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 # | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |R|LRI|B| Reserved | Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . . . Mobility options . . . | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 8. Local Routing Optimization Request Message Sequence Number: A monotonically increasing integer. Set by a sending node in a request message, and used to match a reply to the request. Wu,et al. Expires April 26, 2010 [Page 20] Internet-Draft Proxy MIP Extension for local routing October 2009 'R' flag: Set to 0, indicates it is an routing optimization request message. Bulk localized routing Flag (B): If the bulk localized routing flag (B) is set to 1, then the LROREQ message is a message requesting the MAG or LMA to establish local routing optimization paths between MN and more than one CNs who communicate with MN and MN-CNs pair mobility option will be used to carry one MN and more than one CN. If the bulk localized routing flag is set to 0, then the LROREQ message is a message requesting the MAG or LMA to establish local routing optimization path between one MN and one CN. Local Routing Optimization Indication (LRI) 00: Routing optimization state is unknown or routing optimization is not available 01: The value of Intra-MAG LocalRouting 10: The value of Intra-LMA LocalRouting 11: The value of Inter-LMA local routing Lifetime: The requested time in seconds for which the sender wishes to have local routing. 9.3. Local Routing optimization Response Message(LRORSP) The Local Routing optimization Response message is used to acknowledge the receipt of a Local Routing optimization Request message described in Section 9.2. Wu,et al. Expires April 26, 2010 [Page 21] Internet-Draft Proxy MIP Extension for local routing October 2009 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 # | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |R|LRI|B| Reserved | Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . . . Mobility options . . . | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 9. Local Routing Optimization Response Message Sequence Number: A monotonically increasing integer. Set by a sending node in a request message, and used to match a reply to the request. 'R' flag: Set to 0, indicates it is an routing optimization request message. Set to 1, indicates it is an routing optimization response message. Bulk localized routing Flag (B): If the bulk localized routing flag (B) is set to 1, then the LROREQ message is a message requesting the MAG or LMA to establish local routing optimization paths between MN and more than one CNs who communicate with MN and MN-CNs pair mobility option will be used to carry one MN and more than one CN. If the bulk localized routing flag is set to 0, then the LROREQ message is a message requesting the MAG or LMA to establish local routing optimization path between one MN and one CN. Local Routing Optimization Indication (LRI) 00: Routing optimization state is unknown or routing optimization is not available. 01: The value of Intra-MAG LocalRouting 10: The value of Intra-LMA LocalRouting 11: The value of Inter-LMA Localrouting Lifetime: The requested time in seconds for which the sender wishes to have local routing. Wu,et al. Expires April 26, 2010 [Page 22] Internet-Draft Proxy MIP Extension for local routing October 2009 Mobility options: local Routing optimization mobility option described in section 9.1 and MN-CN pair mobility option described in section 9.4 can be included. 9.4. Context Request Option The details is defined in the section 6.2.1 of [I-D.ietf-mipshop- pfmipv6]. 9.5. MN-CNs pair mobility option A new option, MN-CNs pair mobility option is defined for use with the local Route Optimization Request and local Response messages exchanged between LMA and MAGs. This option is used by the PMIP6 managed node to enable local routing for MN - CNs path from MN connected MAG towards CNs connected a different MAG whose addresses are given in option. The option MUST be used in pairs including one MN, one or many CNs in communication with MN. The order is important. The LMA places the data for MN first in the MN-CNs pair mobility option. 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 |P| Reserved |Prefix Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Home Network Prefix + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Proxy CoA + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 HoA | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 Proxy CoA | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 10. MN-CN pair mobility option P Flag Wu,et al. Expires April 26, 2010 [Page 23] Internet-Draft Proxy MIP Extension for local routing October 2009 P flag is set for IPv4 support. When set IPv4 HoA and IPv4 Proxy CoA fields must be included for MN or CN. Reserved This 7-bit field is unused for now. The value MUST be initialized to 0 by the sender and MUST be ignored by the receiver. Prefix Length 8-bit unsigned integer indicating the prefix length of the IPv6 prefix contained in the option. Home Network Prefix A sixteen-byte field containing the mobile or corresponding node's IPv6 Home Network Prefix. Proxy CoA A sixteen-byte field containing the global address configured on the egress interface of the mobile access gateway to which the mobile or corresponding node is connected. IPv4 HoA Optional 32-bit field containing IPv4 home address of the mobile or corresponding node. IPv4 Proxy CoA Optional 32-bit field containing IPv4 address that is configured on the egress-interface of the mobile access gateway. 10. Security Considerations The protocol specified in this document can use the security association between the LMA and the MAG to create security association between MAGs to which MN and CN attach in the intra-LMA local routing scenario. As regarding intra-MAG local routing scenario, integrity protection can be considered and confidentiality using IPsec is not necessary. 11. IANA Considerations TBD. Wu,et al. Expires April 26, 2010 [Page 24] Internet-Draft Proxy MIP Extension for local routing October 2009 12. Acknowledgement The authors would like to thank Tom Taylor, Kent Leung, Sri Gundavelli, Jouni Korhonen for their review and comments of this draft and all colleagues who have supported the advancement of this draft effort. 13. References 13.1. Normative References [RFC3775] Johnson, D. and al. et, "Mobility Support in IPv6", RFC3775, June 2004 [RFC5213] Gundavelli, S. and al. et, "Proxy Mobile IPv6", RFC5213, May 2008. [RFC4303] Kent,S.,"IP Encapsulation Security Payload(ESP)",RFC4303, December 2005. [I-D.ietf-netlmm-pmip6-ipv4-support] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy Mobile IPv6", draft-ietf-netlmm-pmip6-ipv4-support-09 (work in progress), January 2009. [I-D.ietf-mipshop-pfmipv6] Yokota,H.,Chowdhury,K.,Koodli,R.,Patil,B.,Xia,F.,"Fast handover for Proxy Mobile IPv6",draft-ietf-mipshop-pfmipv6- 05(work in progress),June,2009 13.2. Informative References [I-D.LocalFwd] Koodli,R., Chowdhury,K. "Local Forwarding in Proxy Mobile IPv6", draft-koodli-netlmm-local-forwarding-00, July 2008 [I-D.ietf-netext-pmip6-ro-ps] Liebsch, M.,Jeong,S,Wu,Q. "PMIPv6 Localized Routing Problem Statement", draft-ietf-netext-pmip6-ro-ps-00 (work in progress),February 2009. [I-D.wu-netext-pmipv6-ipv4-ro-ps] Wu,Q., Korhonen, J.," Problem Statement of IPv4 Support for PMIPv6 Localized Routing", draft-wu-netext-pmipv6-ipv4-ro- Wu,et al. Expires April 26, 2010 [Page 25] Internet-Draft Proxy MIP Extension for local routing October 2009 ps-01 (work in progress),June 2009. Appendix A Future Extension A.1. LMA Route Optimization Start Message A.1.1 LMA Route Optimization Start Request Message +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Status | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . . . Mobility Options . . . | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure A 1. LMA Route Optimization Start Request Message A new MH type should be assigned by IANA. Sequence Number 16-bit unsigned integer. The LMA uses this field to match a returned LMAROStartRsp message. The LMA also uses this field to identify each new pairs of MN-CN to start local routing if the LMA received LMAStartRORsp message. Reserved This field is unused. It should be initialized to zero by the sender and MUST be ignored by the receiver. Lifetime 16-bit unsigned integer. If non zero, this fields indicates initial lifetime of MN to CN route optimization binding. If there are several MN-CN pairs, the same lifetime applies to each pair. Mobility Options As defined in section 6.1.7 in [RFC3775]. This document defines a new mobility option: MN-CN RO option in Section 6.4. The sending LMA sends a pair of MN-RO Options. LMA sets Home Network Prefix value of the first MN-RO Option to HNP for MN and Wu,et al. Expires April 26, 2010 [Page 26] Internet-Draft Proxy MIP Extension for local routing October 2009 Proxy-CoA value to Proxy-CoA1. The LMA sets Home Network Prefix value of the second MN-RO Option to HNP of CN and Proxy-CoA value to zero. A.1.2. LMA Route Optimization Start Response Message +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . . . Mobility options . . . | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure A.1.2. LMA Route Optimization Start Response Message A new MH type should be assigned by IANA. Status An 8-bit unsigned integer indicating the disposition of LMAROStartReq message by the receiving LMA. Values less than 128 indicate that ROStartReq message was accepted by the LMA. Values greater than 128 indicate that LMAROStartReq message was rejected by LMA. Sequence number and Lifetime fields are as defined above for LMAROStartReq message. Mobility Options contain pairs of MN-CN RO Option as defined in Section 6.4. The LMA must copy this field from LMAROStartReq message when status field contains a value indicating success. The LMA MUST search its binding cache for the Home Network Prefix value of CN and find the corresponding MAG address, e.g. Proxy-CoA2. Th LMA MUST replace MAG address field set to zero by the sending LMA with Proxy- CoA2. A.2. LMA Initiated Inter-LMA Local Routing The message exchange for the protocol is shown in Figure 7. Inter-LMA Local routing is triggered at one of the LMAs, e.g. LMA1 when a datagram is received on its upstream Wu,et al. Expires April 26, 2010 [Page 27] Internet-Draft Proxy MIP Extension for local routing October 2009 interface whose destination address is a MN, e.g. MN1 for which LMA1 has a binding cache entry. From the binding cache entry, LMA1 determines the MAG address, e.g. MAG1 (Proxy-CoA1). LMA1 checks the source address to find out if the datagram is coming from a MN located in the same PMIPv6 domain and if yes, its MAG address, e.g. MAG2 (Proxy-CoA2). There are several ways for doing this and the exact means is out of scope with the document. Below we will mention two different ways. a. LMAs in the same PMIPv6 domain are configured with a table containing a list of /48, /32, etc. prefixes and the corresponding LMA address for all the LMAs in the domain. LMA1 searches this table doing a longest prefix match based on the prefix part of the source address of MN2 and finds the corresponding LMA2 address. b. LMA1 can exchange with the AAA server to retrieve LMA2 address. LMA1 sends MN2 address and asks LMA address this MN is attached to. LMA1 receives LMA2 address and MAG address (Proxy-CoA2) from AAA server, e.g.DIAMETER server. LMA1 sends LMAROStartRequest message to LMA2. LMAROStartRequest message contains MN1 and MN2 address and MAG1 address (Proxy-CoA1). MAG2 address is set to zero. LMA2 searches its BCE for MN2 and determines MAG2 address (Proxy-CoA2). LMA2 sends LMAROStartResponse message to LMA1. LMAROStartResponse message contains MN1 and MN2 address and MAG1 address (Proxy-CoA1) and MAG2 address (Proxy-CoA2). LMA1 sends LROREQ message to MAG1 at Proxy-CoA1. LROREQ message contains MN address and Proxy- CoA1 and CN address, e.g. MN2 and Proxy-CoA2. LMA2 sends LROREQ message to MAG2 at Proxy-CoA2. LROREQ message contains CN address, e.g. MN2 and Proxy-CoA2 and MN address, e.g. MN1 and Proxy-CoA1. LROREQ messages enable both MAGs to modify their Binding Update Lists. The two MAGs respond LROREQ with LRORSP messages. The two MAGs, MAG1 and MAG2 exchange PBU/PBAs as described in Section 4. Wu,et al. Expires April 26, 2010 [Page 28] Internet-Draft Proxy MIP Extension for local routing October 2009 +------+ +----------+ +---------+ +------+ | MAG1 | | LMA1(MN) | |LMA2(CN) | | MAG2 | +---+--+ +----+-----+ +----+----+ +---+--+ | | | | | | LMAROStartReq | | | |-------------->| | | | | | | | LMARoStartRsp | | | |<------------- | | | LROREQ | | LROREQ | |<---------------| |--------------->| | | | | | LRORSP | | LRORSP | |--------------->| |<-------------- | | | | | |<--------------MAGs exchange PBU/PBA------------>| | | | | | | | | Figure A.2: LMA Initiated Inter-LMA Local routing A.2.1 IPv4 Support Consideration IPv4 support presented in Section 8 also applies here. In addition, we discuss IPv4 support issues related to LMAROStartRequest and LMAStartResponse messages. LMAROStartRequest and LMAStartResponse messages are IPv6 messages. These messages are transported in IPv6 because LMAs support IPv6 and there is IPv6 transport established among LMAs in the same PMIPv6 domain. Wu,et al. Expires April 26, 2010 [Page 29] Internet-Draft Proxy MIP Extension for local routing October 2009 A.3. LMA Initiated operation for Inter-LMA Local Routing Local mobility anchor MUST send LMAROStartReq message to another local mobility anchor in the same PMIPv6 domain. LMAROStartReq message MUST contain at least one pair of MN-CN RO Option. Local mobility anchor MUST place the mobile node address information which is connected to this local mobility anchor first in MN-CN RO Option. Local mobility anchor MAY set lifetime field in LMAROStartReq message to a non zero value. Any nonzero lifetime value enables the receiving local mobility anchor to start local routing optimization for MN-CN traffic by sending LROReq message to the mobility access gateway to which CN is connected as the local mobility anchor determines by searching its binding cache. After receiving LRORes from the mobile access gateway, the local mobility anchor MUST send LMAROStartRes to the originating local mobility anchor. LMAROStartRes MUST contain MN-CN Option RO pair in which the first contains MN and its mobility access gateway address info which is copied from LMAROStartReq message and the second contains CN address which is copies from LMAROStartReq and its mobility access gateway address which this local mobility gateway provides. Local mobility anchor MAY set lifetime field in LMAROStartRes to the same value as LMAROStartReq lifetime field value. Local mobility anchor MAY set lifetime field in LMAROStartRes to a different value. The lifetime field in LMAROStartRes becomes the final value and local mobility anchor MUST set lifetime value in LROReq message that it sends to MN's mobility access gateway. In case the simplified route optimization involves two local mobility gateways, the initiating local mobility anchor MAY stop the route optimization any time it wishes. The initiating local mobility anchor MUST send LMAROStartReq message to the destination local mobility anchor with lifetime field set to zero. The destination local mobility anchor sends LMAROStartRes with lifetime set to zero. Both local mobility anchors send LROReq messages to the corresponding mobility access gateways with lifetime set to zero. Both local mobility anchors reestablish the tunnel with mobility access gateways for MN and CN, respectively. Local mobility anchor sets the sequence number field in LMAROStartReq message to a nonzero integer. This initial sequence number is incremented by one for the next LMAROStartReq message sent. Local mobility anchor MUST receive LMAROStartRes message with the same sequence number as in LMAROStartReq message previously sent. This Wu,et al. Expires April 26, 2010 [Page 30] Internet-Draft Proxy MIP Extension for local routing October 2009 message acknowledges LMAROStartReq message. If no ack is received local mobility anchor MUST retransmit LMAROStartReq message. In a normal mode of operation local mobility anchor has one outstanding LMAROStartReq messages because they are sent to the other local mobility anchor in the same PMIPv6 domain. Appendix B. Change Notes Changes in version 04. O Move LMA Initiated inter-LMA local routing to appendix A O Some Editorial Revision. O Additional text about MAG operation and LMA operation in section 5 and appendix A.3. O Remove NAT Aspect and private IPv4 aspect in this document. O Additional text about Routing Table extension and Bulk localized routing Flag. Wu,et al. Expires April 26, 2010 [Page 31] Internet-Draft Proxy MIP Extension for local routing October 2009 Authors' Addresses Qin Wu Huawei Technologies Co.,Ltd Site B,Floor 12F,Huihong Mansion,No.91,Baixia Rd. Nanjing 210001 China Email: Sunseawq@huawei.com Behcet Sarikaya Huawei Technologies Co.,Ltd 1700 Alma Dr.Suite 500 Plano, TX 75075 USA Email: sarikaya@ieee.org Wu,et al. Expires April 26, 2010 [Page 32]