NETLMM Working Group V. Devarapalli Internet-Draft H. Lim Intended status: Standards Track N. Kant Expires: August 22, 2008 Azaire Networks S. Krishnan Ericsson February 19, 2008 Heartbeat Mechanism for Proxy Mobile IPv6 draft-devarapalli-netlmm-pmipv6-heartbeat-01.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of 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 August 22, 2008. Copyright Notice Copyright (C) The IETF Trust (2008). Abstract Proxy Mobile IPv6 is a network-based mobility management protocol. The mobility entities involved in the Proxy Mobile IPv6 protocol, the Mobile Access Gateway (MAG) and the Local Mobility Anchor (LMA), setup tunnels dynamically to manage mobility for a mobile node within the Proxy Mobile IPv6 domain. This document describes a heartbeat Devarapalli, et al. Expires August 22, 2008 [Page 1] Internet-Draft PMIPv6 Heartbeat Mechanism February 2008 mechanism between the MAG and the LMA to detect failures quickly and take appropriate action. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Heartbeat Mechanism . . . . . . . . . . . . . . . . . . . . . . 3 3.1. Failure Detection . . . . . . . . . . . . . . . . . . . . . 4 3.2. Heartbeat Message . . . . . . . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 6 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 7.1. Normative References . . . . . . . . . . . . . . . . . . . 6 7.2. Informative References . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7 Intellectual Property and Copyright Statements . . . . . . . . . . 9 Devarapalli, et al. Expires August 22, 2008 [Page 2] Internet-Draft PMIPv6 Heartbeat Mechanism February 2008 1. Introduction Proxy Mobile IPv6 enables network-based mobility for IPv6 hosts that do not implement any mobility protocols. The protocol is described in detail in [2]. The Local Mobility Anchor (LMA) acts the anchor for the mobile node sessions as long as the mobile node is attached to the Proxy Mobile IPv6 domain. For the definition of Proxy Mobile IPv6 domain, see [2]. The mobile node is at any time attached to a Mobile Access Gateway (MAG) that manages mobility for the mobile node. The MAG and the LMA set up IP-in-IP tunnels to tunnel all traffic that belongs to the mobile node. If the LMA crashes or if there is a communication problem on the path between the MAG and the LMA, the MAG discovers this only when it sends the next proxy Binding Update and gets no response from the LMA. If a MAG becomes unreachable, the LMA can detect it only when it starts receiving ICMP unreachable messages from an intermediate router in response to data traffic the LMA tunnels to the MAG. For some deployments of Proxy Mobile IPv6, it is desirable to detect the LMA or the MAG reachability failure very early, so that appropriate action could be taken. The appropriate actions, for example, releasing resources, is out of scope for this document. This document proposes a heartbeat mechanism between the MAG and the LMA to detect the current status of reachability between them. The heartbeat message is a mobility header message (protocol type 135). The MAG and the LMA exchange heartbeat messages every few seconds to detect if the other end is still reachable. The interval between consecutive heartbeats is configurable. 2. Terminology 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 [1]. 3. Heartbeat Mechanism The MAG and the LMA exchange heartbeat messages every HEARTBEAT_INTERVAL seconds to detect the current status of reachability between them. A MAG typically initiates the heartbeat exchange by sending a Heartbeat Request to the LMA. Each Heartbeat Request contains a sequence number that is incremented sequentially. The sequence number on the last Heartbeat Request message is always recorded by the MAG. The HEARTBEAT_INTERVAL is carried in the Heartbeat Request message. The Heartbeat message is described in Devarapalli, et al. Expires August 22, 2008 [Page 3] Internet-Draft PMIPv6 Heartbeat Mechanism February 2008 more detail in Section 3.2. A heartbeat message can be sent only if the MAG has at least one proxy binding cache entry at the LMA for a mobile node attached to the MAG. If there are no proxy binding cache entries at the LMA for any of the mobile nodes attached to the MAG, then the heartbeat messages MUST NOT be sent. When the LMA receives a Heartbeat Request message, it responds with a Heartbeat Response message. The sequence number and the heartbeat interval in the Heartbeat Request message are recorded on the LMA. The LMA copies the sequence number from the Heartbeat Request message onto the Heartbeat Response message. The Heartbeat Interval field is set to 0 in the Heartbeat Response message. The HEARTBEAT_INTERNAL SHOULD NOT be configured to a value less than 30 seconds. Sending heartbeat messages too often may become an overhead on the path between the MAG and the LMA. The LMA MAY also send a one-time Heartbeat Request message to the MAG to check a MAG's reachability status. The Heartbeat Interval in the Heartbeat Request message is set to 0 to indicate that it is a one- time message and is not transmitted periodically. If a MAG receives a Heartbeat Request message from the LMA, it MUST respond with a Heartbeat Response message. If the LMA or the MAG do not support the heartbeat messages, they should respond with an ICMP Parameter Problem, Code 0, message to the initiator. The 'Pointer' field in the ICMP Parameter Problem message SHOULD point to the 'MH Type' field, indicating that the particular Mobility Header message is not supported. When the ICMP Parameter Problem message is received in response to Heartbeat Request message, the initiating MAG or the LMA MUST NOT use heartbeat messages with the other end again. 3.1. Failure Detection If the MAG does not receive more than MISSING_HEARTBEATS_ALLOWED number of responses from the LMA, it concludes that the LMA is not reachable. The MISSING_HEARTBEATS_ALLOWED value is configurable on the MAG. The MAG may then take appropriate action (out of scope for this document). The LMA also has a MISSING_HEARTBEATS_ALLOWED counter configured per MAG. The LMA knows how often to expect a heartbeat message from the MAG based on the Heartbeat Interval in the first Heartbeat Request message received from the MAG. If the LMA does not receive more than MISSING_HEARTBEATS_ALLOWED Heartbeat Request messages from the MAG, Devarapalli, et al. Expires August 22, 2008 [Page 4] Internet-Draft PMIPv6 Heartbeat Mechanism February 2008 it concludes that the MAG is not reachable. The LMA may also optionally send a Heartbeat Request message to the MAG before concluding that the MAG is unreachable. The Heartbeat Interval value is set to 0 to indicate that this is a one-time heartbeat message and is not sent periodically. If the LMA does not get a response from the MAG, it re-transmits the Heartbeat Request message. The number of times the Heartbeat Request is re-transmitted is configurable on the LMA. If a response from the MAG is received, then the LMA concludes that the MAG is reachable and resets the MISSING_HEARTBEATS_ALLOWED counter for the particular MAG. 3.2. Heartbeat Message The following illustrates the message format for the Heartbeat Mobility Header message. The 'MH Type' field in the Mobility Header indicates that it is a Heartbeat message. 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 | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Heartbeat Interval | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type A 8-bit field that indicates whether the message is a request or a response. A value of '1' indicates that it is a request. A value of '2' indicates that it is a response. Reserved A 8-bit field set to 0 and ignored by the receiver. Sequence Number A 32-bit sequence number used for matching the request to the reply. Devarapalli, et al. Expires August 22, 2008 [Page 5] Internet-Draft PMIPv6 Heartbeat Mechanism February 2008 Heartbeat Interval A 32-bit value indicating the interval in seconds between two consecutive heartbeat messages. A value of 0 indicates that the Heartbeat message is just a one-time message and not sent periodically. 4. Security Considerations The heartbeat messages are just used for checking reachability between the MAG and the LMA. They do not carry information that is useful for eavesdroppers on the path. Integrity protection using IPsec [3] for the heartbeat messages MUST be supported on the MAG and the LMA. The use of IPsec protection is optional. Confidentiality protection is not required. For dynamic key negotiation between the MAG and the LMA, IKEv2 [4] SHOULD be used. 5. IANA Considerations The Heartbeat message defined in Section 3.2 must have the type value allocated from the same space as the 'MH Type' field in the Mobility Header defined in RFC 3775 [5]. 6. Acknowledgments A heartbeat mechanism for a network-based mobility management protocol was first described in [6]. The authors would like to thank the members of a NETLMM design team that produced that document. The mechanism described in this document also derives from the path management mechanism described in [7]. We would also like to thank Alessio Casati for first suggesting a fault handling mechanism for Proxy Mobile IPv6. 7. References 7.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., and Devarapalli, et al. Expires August 22, 2008 [Page 6] Internet-Draft PMIPv6 Heartbeat Mechanism February 2008 B. Patil, "Proxy Mobile IPv6", draft-ietf-netlmm-proxymip6-10 (work in progress), February 2008. [3] Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", RFC 4301, December 2005. [4] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol", RFC 4306, December 2005. 7.2. Informative References [5] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in IPv6", RFC 3775, June 2004. [6] Giaretta, G., "The NetLMM Protocol", draft-giaretta-netlmm-dt-protocol-02 (work in progress), October 2006. [7] 3rd Generation Parternship Project, "3GPP Technical Specification 29.060 V7.6.0: "Technical Specification Group Core Network and Terminals; General Packet Radio Service (GPRS); GPRS Tunnelling Protocol (GTP) across the Gn and Gp interface (Release 7)"", July 2007. Authors' Addresses Vijay Devarapalli Azaire Networks 3121 Jay Street Santa Clara, CA 95054 USA Email: vijay.devarapalli@azairenet.com Heeseon Lim Azaire Networks 3121 Jay Street Santa Clara, CA 95054 USA Email: heeseon.lim@azairenet.com Devarapalli, et al. Expires August 22, 2008 [Page 7] Internet-Draft PMIPv6 Heartbeat Mechanism February 2008 Nishi Kant Azaire Networks 3121 Jay Street Santa Clara, CA 95054 USA Email: nishi.kant@azairenet.com Suresh Krishnan Ericsson 8400 Decarie Blvd. Town of Mount Royal, QC Canada Email: suresh.krishnan@ericsson.com Devarapalli, et al. Expires August 22, 2008 [Page 8] Internet-Draft PMIPv6 Heartbeat Mechanism February 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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