Network Working Group G. Montenegro Internet-Draft Microsoft Corporation Expires: January 12, 2006 N. Kushalnagar Intel Corp July 11, 2005 AODV for IEEE 802.15.4 Networks draft-montenegro-lowpan-aodv-00 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 January 12, 2006. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This document describes how to use the Ad Hoc On-Demand Vector Protocol (AODV) in IEEE 802.15.4 networks. Montenegro & Kushalnagar Expires January 12, 2006 [Page 1] Internet-Draft AODV over IEEE 802.15.4 July 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 Requirements notation . . . . . . . . . . . . . . . . . . 3 2. AODV Operation over IEEE 802.15.4 . . . . . . . . . . . . . . 3 3. Suggested AODV Simplifications . . . . . . . . . . . . . . . . 4 4. Packet Delivery in a Mesh . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 6. Security Considerations . . . . . . . . . . . . . . . . . . . 5 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 8.1 Normative References . . . . . . . . . . . . . . . . . . . 5 8.2 Informative References . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 7 Intellectual Property and Copyright Statements . . . . . . . . 8 Montenegro & Kushalnagar Expires January 12, 2006 [Page 2] Internet-Draft AODV over IEEE 802.15.4 July 2005 1. Introduction The IEEE 802.15.4 standard [ieee802.15.4] targets low power personal area networks. The "IPv6 over IEEE 802.15.4" document [I-D.montenegro-lowpan-ipv6-over-802.15.4] defines basic functionality required to carry IPv6 packets over IEEE 802.15.4 networks (including an adaptation layer, header compression, etc). Likewise, the functionality required for packet delivery in IEEE 802.15.4 meshes is defined, as mesh topologies are expected to be common in LoWPAN networks. However, neither the IEEE 802.15.4 standard nor the "IPv6 over IEEE 802.15.4" specification provide any information as to how such a mesh topology could be obtained and maintained. This document specifies how to use the Ad Hoc On-Demand Vector Protocol (AODV) [RFC3561] to provide mesh routing in IEEE 802.15.4 networks. To distinguish this instantiation of the protocol from AODV over IPv4 and AODV over IPv6, the label "LoWPAN-AODV" is used in this document. Given the very stringent limitations of the target devices, this document offers guidance regarding simplifications that are recommended to the base AODV specification. Given the specificity of certain deployment scenarios, it is not expected that AODV will always be the best choice for a mesh routing protocol. Nevertheless, specifying how other mesh routing protocols may apply is out of scope of this document. 1.1 Requirements notation 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]. 2. AODV Operation over IEEE 802.15.4 Except for the exceptions mentioned in this section, AODV operation over IEEE 802.15.4 networks is as defined in [I-D.perkins-manet- aodvbis]. The addresses used in AODV control messages are IEEE 802.15.4 IEEE 64-bit extended addresses [EUI64] (however, 16-bit short address support may be added later). Additionally, it should be noted that as used in this specification, AODV is not layered on top of IP, but underneath it. It is an underlay. As such, it creates a mesh network topology underneath and unbeknownst to IP. IP sees a PAN as a single link. This is similar to how other technologies regularly create complex structures underneath IP (e.g., ethernet spanning tree bridges, token ring source routing, ATM, etc). Of course, this does not preclude simultaneously using AODV above IP. One can envision a Montenegro & Kushalnagar Expires January 12, 2006 [Page 3] Internet-Draft AODV over IEEE 802.15.4 July 2005 sub-IP mesh creating the illusion that all the devices on that PAN are on the same IPv6 link (sharing the same IPv6 prefix). At the same time, normal usage of AODV (above IP) could tie together several such "links" (potentially using different technologies for each) into a larger mesh. AODV over IPv4 makes use of broadcast in its route discovery. It does so in order to propagate the Route Request control packets (RREQs). In this specification, such broadcast packets are obtained by setting the PAN id to the broadcast PAN (0xffff) and by setting the destination address to the broadcast short address (0xffff) AODV control packets use the encapsulation defined in [I-D.montenegro-lowpan-ipv6-over-802.15.4]. All AODV control packets shall use the prot_type value TBD (suggested value of 4). This prot_type is used to send AODV messages in a manner similar to how normal AODV uses the properly assigned UDP port (654). In both cases, the different types of AODV control packets (i.e., RREQ, RREP, RERR and RREP-ACK) are handled via Types. This specification uses the same Types and message formats as defined for normal AODV [I-D.perkins-manet-aodvbis]. 3. Suggested AODV Simplifications Besides the main AODV specification [RFC3561], several efforts aim at further correctness [I-D.perkins-manet-aodvbis] or simplifications of the protocol, as in the AODVjr proposal [AODVjr] or the TinyAODV implementation [TinyAODV]. Similarly, DyMO allows for minimalist implementation leaving non-essential functionality as optional [I-D.ietf-manet-dymo]. In keeping with the spirit of the above, LoWPAN-AODV simplifies AODV as follows: o The only AODV control messages required to be implemented are RREQ (Route Request) and RREP (Route Reply). o Only the final destination responds to a RREQ by sending an RREP. o Only hop count is used to determine best routes. o Hello messages are not used. Instead, the IEEE 802.15.4 acknowledgement mechanism is used to determine if a neighbor is no longer responsive. This information is obtained when transmitting a packet with acknowledgements turned on. 4. Packet Delivery in a Mesh Packet delivery is done by using the "Final Destination" field defined and procedures defined in [I-D.montenegro-lowpan-ipv6-over- Montenegro & Kushalnagar Expires January 12, 2006 [Page 4] Internet-Draft AODV over IEEE 802.15.4 July 2005 802.15.4]. 5. IANA Considerations This document requests that IANA assign a value out of the prot_type (Protocol Type) registry defined in [I-D.montenegro-lowpan-ipv6-over- 802.15.4]. The value requested is for LoWPAN-AODV (suggested value: 4). 6. Security Considerations TBD. 7. Acknowledgements TBD. 8. References 8.1 Normative References [EUI64] "GUIDELINES FOR 64-BIT GLOBAL IDENTIFIER (EUI-64) REGISTRATION AUTHORITY", IEEE http://standards.ieee.org/ regauth/oui/tutorials/EUI64.html. [I-D.ietf-ipv6-2461bis] Narten, T., "Neighbor Discovery for IP version 6 (IPv6)", draft-ietf-ipv6-2461bis-03 (work in progress), May 2005. [I-D.ietf-ipv6-rfc2462bis] Thomson, S., "IPv6 Stateless Address Autoconfiguration", draft-ietf-ipv6-rfc2462bis-08 (work in progress), May 2005. [I-D.montenegro-lowpan-ipv6-over-802.15.4] Montenegro, G., "Transmission of IPv6 Packets over IEEE 802.15.4 Networks", draft-montenegro-lowpan-ipv6-over-802.15.4-02 (work in progress), February 2005. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 Montenegro & Kushalnagar Expires January 12, 2006 [Page 5] Internet-Draft AODV over IEEE 802.15.4 July 2005 (IPv6) Specification", RFC 2460, December 1998. [RFC3513] Hinden, R. and S. Deering, "Internet Protocol Version 6 (IPv6) Addressing Architecture", RFC 3513, April 2003. [RFC3561] Perkins, C., Belding-Royer, E., and S. Das, "Ad hoc On- Demand Distance Vector (AODV) Routing", RFC 3561, July 2003. [ieee802.15.4] IEEE Computer Society, "IEEE Std. 802.15.4-2003", October 2003. 8.2 Informative References [AODVjr] Chakeres, Ian and Klein-Berndt, Luke, "AODVjr, AODV Simplified", ACM SIGMOBILE Mobile Computing and Communications Review pp. 100-101, July 2002. [I-D.ietf-ipngwg-icmp-v3] Conta, A., "Internet Control Message Protocol (ICMPv6)for the Internet Protocol Version 6 (IPv6) Specification", draft-ietf-ipngwg-icmp-v3-06 (work in progress), November 2004. [I-D.ietf-manet-dymo] Chakeres, I., "Dynamic MANET On-demand (DYMO) Routing", draft-ietf-manet-dymo-02 (work in progress), June 2005. [I-D.perkins-manet-aodvbis] Perkins, C., "Ad hoc On-Demand Distance Vector (AODV) Routing", draft-perkins-manet-aodvbis-01 (work in progress), February 2004. [KW03] Karlof, Chris and Wagner, David, "Secure Routing in Sensor Networks: Attacks and Countermeasures", Elsevier's AdHoc Networks Journal, Special Issue on Sensor Network Applications and Protocols vol 1, issues 2-3, September 2003. [RFC3439] Bush, R. and D. Meyer, "Some Internet Architectural Guidelines and Philosophy", RFC 3439, December 2002. [RFC3756] Nikander, P., Kempf, J., and E. Nordmark, "IPv6 Neighbor Discovery (ND) Trust Models and Threats", RFC 3756, May 2004. [TinyAODV] Montenegro & Kushalnagar Expires January 12, 2006 [Page 6] Internet-Draft AODV over IEEE 802.15.4 July 2005 "TinyAODV Implementation", TinyOS Source Code Repository h ttp://cvs.sourceforge.net/viewcvs.py/tinyos/tinyos-1.x/ contrib/hsn/. Authors' Addresses Gabriel Montenegro Microsoft Corporation Email: gabriel_montenegro_2000@yahoo.com Nandakishore Kushalnagar Intel Corp Email: nandakishore.kushalnagar@intel.com Montenegro & Kushalnagar Expires January 12, 2006 [Page 7] Internet-Draft AODV over IEEE 802.15.4 July 2005 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. 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