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DSR Status Update David B. Johnson Rice University Department of Computer Science http://www.monarch.cs.rice.edu/ [email protected] 55th IETF Monarch Project DSR: Dynamic Source Routing Protocol Divides routing problem into two parts: • Route Discovery: only try to find a route to some destination when you don’t have one and need one • Route Maintenance: only while you’re actually using a route, try to keep it working or fix it in spite of changes Important properties of DSR: • All aspects of protocol operation are entirely on-demand • Nodes ignore all topology changes not affecting them • Overhead scales automatically as movement increases • Zero overhead when stationary and found routes already • Also can support unidirectional links and asymmetric routes • Extensive implementation and demonstration with real workloads New DSR Implementation Work Implementation under Windows jointly with Microsoft Research: • Implemented at the link layer • Uses the same primitives as DSR: – Route Discovery – Route Maintenance (explicit, due to NDIS limitations) – Source routing • Packet formats based on those in the DSR Internet-Draft • Not fully optimized (salvaging, expanding ring) • We plan (and expect) to be able to release the code Recent Papers (Security) • Yih-Chun Hu, David B. Johnson, and Adrian Perrig. SEAD: Secure Efficient Distance Vector Routing for Mobile Wireless Ad Hoc Networks. WMCSA 2002, June 2002. • Yih-Chun Hu, Adrian Perrig, and David B. Johnson. Ariadne: A Secure On-Demand Routing Protocol for Ad Hoc Networks. MobiCom 2002, September 2002. • Yih-Chun Hu, Adrian Perrig, and David B. Johnson. Efficient Security Mechanisms for Routing Protocols. NDSS 2003, February 2003, to appear. • Yih-Chun Hu, Adrian Perrig, and David B. Johnson. Packet Leashes: A Defense against Wormhole Attacks in Wireless Ad Hoc Networks. INFOCOM 2003, April 2003, to appear. Recent Papers (Other) • Yih-Chun Hu and David B. Johnson. Design and Demonstration of Live Audio and Video over Multihop Wireless Ad Hoc Networks. MILCOM 2002, October 2002. • Yih-Chun Hu and David B. Johnson. Ensuring Cache Freshness in On-Demand Ad Hoc Network Routing Protocols. POMC 2002, October 2002. • Santashil PalChaudhuri and David B. Johnson, Power Mode Scheduling for Ad Hoc Networks (Extended Abstract), ICNP 2002, November 2002. Internet-Draft Status Adding some things (back) to the draft: • Have been in previous drafts: draft-ietf-manet-dsr-03.txt, Oct 1999: – Use of multiple network interfaces – Implicit source routing And of course, lots of proofreading of the draft Expect to complete final version of draft by end of December Use of Multiple Network Interfaces • Allows routing between different types of networks • Example: some nodes have both short-range and long-range radios, but most have only short-range • Also allows integration with Internet and Mobile IP • Implemented and demonstrated in DSR testbed, Pittsburgh, December 1998 through March 1999 • Documented in: – Josh Broch, David A. Maltz, and David B. Johnson. Supporting Hierarchy and Heterogeneous Interfaces in Multi-Hop Wireless Ad Hoc Networks. In Proceedings of the Workshop on Mobile Computing, ISPAN’99, June 1999 – David A. Maltz, Josh Broch, and David B. Johnson. Lessons From a Full-Scale Multi-Hop Wireless Ad Hoc Network Testbed. IEEE Personal Communications, February 2001 Implicit Source Routing • Establishes hop-by-hop state based on source route from sender • Avoids carrying source route in most packets • All state is soft state – no correctness problems if it is lost • Implemented and demonstrated in DSR QoS demo, DARPA GloMo PI meeting, Eatontown, NJ, July 2000 • Documented in: – Yih-Chun Hu and David B. Johnson. Implicit Source Routes for On-Demand Ad Hoc Network Routing. In Proceedings MobiHoc 2001, October, 2001. – Yih-Chun Hu and David B. Johnson. Design and Demonstration of Live Audio and Video over Multihop Wireless Ad Hoc Networks. In Proceedings of MILCOM 2002, October 2002.