INTERNET-DRAFT H. Jiang Intended Status: Proposed Standard Huawei Expires: December 31, 2012 June 29, 2012 Fault Tolerant Support for The Multihomed MN in Proxy Mobile IPv6 draft-jiang-netext-ft-pmip-00 Abstract Proxy Mobile IPv6 (PMIPv6) is standardized by IETF to supply mobility management for mobile nodes (MN) in a local small area. If the multihomed MN attaches to multiple MAGs by multiple links, then the mobility session in each link is independent. As the ongoing communication interface breaking down, the mobility session in the link is also broke and the traffic packets are lost. This document mainly proposes a fault tolerant scheme. When an interface of the multihomed MN broke down, the fault tolerant scheme can be used to handover the interface and realize the flow migration and maintain the integrity of data transmission During the handover process. 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/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Copyright and License Notice Copyright (c) 2012 IETF Trust and the persons identified as the H. Jiang Expires December 31, 2012 [Page 1]
INTERNET DRAFT Fault Tolerant Scheme for PMIPv6 June 29, 2012 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Requirements and Terminology . . . . . . . . . . . . . . . . . 3 2.1 Requirements . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 Terminology . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Fault Tolerant Scheme . . . . . . . . . . . . . . . . . . . . 4 3.1 LMA Operation . . . . . . . . . . . . . . . . . . . . . . . 4 3.2 Fault Tolerant Handover . . . . . . . . . . . . . . . . . . 4 4 Security Considerations . . . . . . . . . . . . . . . . . . . . 6 5 IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 6 References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 6.1 Normative References . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 H. Jiang Expires December 31, 2012 [Page 2]
INTERNET DRAFT Fault Tolerant Scheme for PMIPv6 June 29, 2012 1. Introduction With the development of the Internet business, the customer cannot obtain the consecutive and high quality communication service as adopting one access technology to join the network. The emerging of the new technologies results in the situation that the Mobile Node (MN) can use multiple interfaces to access the network with multiple technologies, which can be summarized as multihoming. Especially in the future network, multihoming will absolutely be the necessary technology and be used to increase the reliability of the network application. In order to promoting the widespread deployment of the MN, mobile operators should consider the mobility management in the network. Thus the network based mobility management protocol - Proxy Mobile IPv6 (PMIPv6) was proposed to fulfill the mobility management requirements. PMIPv6 network mainly includes two function entities: Mobile Access Gateway (MAG) and Local Mobility Anchor (LMA). MAG takes the place of MN to deal with the mobility relating signaling. Generally the first hop router which MN is attaching takes this role. In the meanwhile MAG SHOULD track the MN in the PMIPv6 domain. The number of MAGs in a single domain is not limited. LMA SHOULD be responsible for associating MN with MAG and storing all the routing information to reach each MN. The Tunnel between LMA and MAG is used by MN to transmit the traffic flow. In PMIPv6, Binding Cache Entry (BCE) is created in LMA to binding the MAG with MN. Each BCE entry is only corresponding to one mobility session of the MN. If the multihomed MN attaches to multiple MAGs by multiple links, then the mobility session in each link is independent. When the ongoing communication interface breaking down, the mobility session in the link is also broke and the traffic packets are lost. LMA will remove the BCE entry that corresponding to the interface, thus the multihomed MN cannot receive data packets from this interface. Because MN does not involve in the signaling handover, MAG is unable to distinguish whether the handover was occurred between the two interfaces of the MN. Based on the problem stated above, this document proposes a fault tolerant scheme focusing on the multihomed MN in the PMIPv6 network. Two aspects are considered: 1) when an interface of the multihomed MN breaks down, the fault tolerant scheme can be used to handover the interface; 2) the fault tolerant scheme can realize the flow migration and maintain the integrity of data transmission in the process of interface handover. 2. Requirements and Terminology H. Jiang Expires December 31, 2012 [Page 3]
INTERNET DRAFT Fault Tolerant Scheme for PMIPv6 June 29, 2012 2.1 Requirements 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 of the terminology used in this document are already defined in [RFC5213]. 3. Fault Tolerant Scheme 3.1 LMA Operation In order to achieve the interface handover for the multihomed MN without transmission interruption, the data structure of the original BCE table SHOULD be extended as follows: the multihoming flag and the Status flag SHOULD be included in the new BCE entry. The multihoming flag is used to identify if the MN is the multihomed. When the multihomed MN joins the network, MAG is used to communicate with LMA to register the location information for MN and sends the Proxy Binding Update (PBU) message to LMA. LMA creates a BCE entry for each interface of MN. If the received PBU messages from different MAGs with the same MN-ID, the multihoming flag is set as 1; otherwise the value is set as 0. The status flag is used to identify whether the interface that the BCE entry corresponds is available, or whether the state of the interface is in use. The value is set as 1 when the interface is available; otherwise the value is set as 0. 3.2 Fault Tolerant Handover Considering that the multihomed MN attaches MAG1 and MAG2 through interface IF1 and IF2 respectively to join the PMIPv6 domain. After the access authentication, LMA allocates the same HNP (HNP1) for IF1 and IF2. Then LMA creates the BCE entries Entry1 and Entry2. By comparing the MN-ID of Entry1 and Entry2, LMA identifies that the MN- ID of Entry1 and Entry2 is the same, which implies that Entry1 and Entry2 belonging to the same MN. Then LMA associates Entry1 with Entry2 by MN-ID to facilitate the lookup and storage. After that two bi-direction data tunnel Tunnel1 and Tunnel2 are setup from LMA to MAG1 and MAG2. LMA respectively send PBA messages to inform MAG1 and MAG2. Afterwards MAG1 and MAG2 all send the Router Advertisement messages to inform IF1 and IF2 to configure the IP address. Then the multihomed MN actively communicates with Corresponding Node (CN) H. Jiang Expires December 31, 2012 [Page 4]
INTERNET DRAFT Fault Tolerant Scheme for PMIPv6 June 29, 2012 through IF1. When IF1 is breaking down, the data of CN sent from LMA to MAG1 cannot reach the MN, and then MAG1 begins to cache the data for MN; At the same time MAG1 sends the DeReg PBU message to LMA for informing the IF1 fault; After receiving the DeReg PBU message, LMA begins to update the BCE entry; then LMA sends the PBA message to MAG1; MAG1 forwards the cached data to LMA by Tunnel; then LMA checks the BCE table and finds out that IF2 is available, so the cached data are sent to MAG2 by Tunnel2; then CN will communicates with the multihomed MN by Tunnel2. The detailed process is shown in Figure 1. +----+----+ +------+ +------+ +------+ +----+ | IF1| IF2| | MAG1 | | MAG2 | | LMA | | CN | +----+----+ +------+ +------+ +------+ +----+ | | | | | | |IF1 is unreachable| CN sends packets to IF1 of MN by Tunnel1 | |<-----------------|<---------------------------------------------| | | | | | | | | Caching data for MN | | | | | | | | | | | | MAG1 sends DeReg PBU to LMA | | | | |----------------------------->| | | | | | | | | | | | Updating the BCE entry for MN | | | | |------------------------------>| | | | | | | | | | LMA sends PBA to MAG1 | | | | |<-----------------------------| | | | | | | | | | | MAG1 sends cached data to LMA| | | | |----------------------------->| | | | | | | | | | MAG2 forwards the cached |LMA sends cached | | | data to IF2 of MN | data to MAG2 | | | |<---------------------------|<--------------| | | | | | | | | | CN communicates with the IF2 of MN by Tunnel2 | | |<-----------------------------------------------------------| | | | | | | | | | | | | Figure 1: the signaling process of interface handover (1) CN sends the data packets to MN through the bi-direction Tunnel between LMA and MAG1; (2) MAG1 detects that IF1 is unreachable and begins to cache data H. Jiang Expires December 31, 2012 [Page 5]
INTERNET DRAFT Fault Tolerant Scheme for PMIPv6 June 29, 2012 for MN; (3) MAG1 sends the DeReg PBU message to LMA (see RFC5213) to feedback; (4) After receiving the DeReg PBU message, LMA updates the BCE entry for the multihomed MN; (5) LMA sends the PBA message to MAG1 for confirmation; (6) MAG1 sends the cached data to LMA; (7) The cached data from LMA will be forwarded to MAG2 through Tunnel2 and reach the destination MN; (8) CN keeps on sending data packets to MN through Tunnel2 between LMA and MAG2. 4 Security Considerations This document raises no new security issues for PMIPv6 network. 5 IANA Considerations None 6 References 6.1 Normative References [RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", RFC5213, August 2008. [RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support in IPv6", RFC6275, July 2011. Authors' Addresses Haisheng Jiang Huawei Building, No.156 Beiqing Rd. Z-park ,Shi-Chuang-Ke-Ji-Shi-Fan-Yuan,Hai-Dian District, Beijing 100095 P.R. China EMail: haisheng.jiang@huawei.com H. Jiang Expires December 31, 2012 [Page 6]
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