Distributed Mobility Managment Working D. Liu Group H. Deng Internet-Draft China Mobile Intended status: Standards Track March 5, 2012 Expires: September 6, 2012 Address Selection for DMM draft-liu-dmm-address-selection-00 Abstract In DMM scenario, it is possible for the MN to have multiple mobility anchor points and corresponding prefixes. In that case, MN needs to know the type of the addresses then it can select the right one for application to use. This document describes a mechnism to extend RA message to carry a flag which can be used to identify the nature of the prefix. 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]. 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 September 6, 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 Liu & Deng Expires September 6, 2012 [Page 1] Internet-Draft draft-liu-dmm-address-selection-00 March 2012 (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. Problem of address selection for DMM . . . . . . . . . . . . . 3 2. Extension to Router Advertisment . . . . . . . . . . . . . . . 3 3. Mobile Node Operation . . . . . . . . . . . . . . . . . . . . . 4 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.1. Normative References . . . . . . . . . . . . . . . . . . . 5 7.2. Informative References . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 Liu & Deng Expires September 6, 2012 [Page 2] Internet-Draft draft-liu-dmm-address-selection-00 March 2012 1. Problem of address selection for DMM As draft-liu-dmm-dynamic-anchor-discussion-00 introduced, there is a address selection problem for DMM dynamic anchor solution. The difficulty of this problem is: the MN does not know the difference between the multiple prefixes. There is no way for the network to tell the MN the nature of the different prefixes and there is no standard mechnism for the MN to select the right prefix. 2. Extension to Router Advertisment Mobile IPv6 [RFC3775] extend IPv6 router advertisement message for movement detection and home agent information broadcasting. This document proposes to further extend the IPv6 router advertisement message to carry a flag to identify the nature of the prefix that it is advertising. +----------+---------+-------------------+ | Type | Code | Checksum | +----------+-+-+-+---+-------------------+ |Hop Limit |M|O|H|Re-| Router Lifetime| +----------+-+-+-+---+-------------------+ | Reachable Time | +----------------------------------------+ | Retrans Timer | +----------------------------------------+ | Options | +----------------------------------------+ The H bit is used for indentify that the router advertisment is sent by a home agent. +-------------+------------+------------+-+-+-+--+---+ | Type | Length |PrefixLength|L|A|R|T |R- | +-------------+------------+------------+-+-+-+--+---+ | Valid Lifetime | +----------------------------------------------------+ | Preferred Lifetime | +----------------------------------------------------+ | Reserved | +----------------------------------------------------+ | | | Prefix | +----------------------------------------------------+ Liu & Deng Expires September 6, 2012 [Page 3] Internet-Draft draft-liu-dmm-address-selection-00 March 2012 This document proposes to extend the prefix information option to add a 'T' flag, its definition is as follows: T (Type): Type flag. This is a 2 bits flag indentifies the types of the advertising prefix. The value of this flag could be: 00: Local home network prefix. It means that this prefix is allocated and advertised by current router which the MN attaches to. 01 : Remote home network prefix. It means that this prefix is allocated by another router instead of the router that the MN currently attaches to. 10: Reserved. 11: Reserved. The mechanism that used for the router to identify the types of the prefix is out the scope of this document. As an example, the router can query the policy server to know which router allocates a particular prefix. 3. Mobile Node Operation The mobile node knows the types of the prefixes from the T flag of the router advertisment message. The applications on the mobile node can use this information to select the right IP address. For example, for on-going session, application always choose to use the prefix that it used before it handovers to a new location. For the newly initiate application, it will use the prefix that allocated by current router, e.g. local home network prefix. The mobile node can use advanced socket API to select the proper prefix, for example, extension to RFC 5014.The detail mechnism is out the scope of this document. 4. IANA Considerations This document makes no request of IANA. Note to RFC Editor: this section may be removed on publication as an RFC. Liu & Deng Expires September 6, 2012 [Page 4] Internet-Draft draft-liu-dmm-address-selection-00 March 2012 5. Security Considerations TBD 6. Acknowledgements TBD 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 7.2. Informative References [I-D.draft-seite-dmm-dma-00] "Distributed Mobility Anchoring", February 2012. Authors' Addresses Dapeng Liu China Mobile 32 Xuanwumen West Street Beijng, Xicheng District 100053 China Phone: +86-13911788933 Email: liudapeng@chinamobile.com Hui Deng China Mobile 32 Xuanwumen West Street Beijng, Xicheng District 100053 China Phone: Fax: Email: denghui@chinamobile.com URI: Liu & Deng Expires September 6, 2012 [Page 5]