David B. Johnson Rice University Department of Computer Science DSR Status Update Monarch Project 55th IETF

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 Yih-Chun Hu, Adrian Perrig, and David B. Johnson. Ariadne: A Secure On-Demand Routing Protocol for Ad Hoc Networks. MobiCom 2002, September 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 Yih-Chun Hu and David B. Johnson. Ensuring Cache Freshness in On-Demand Ad Hoc Network Routing Protocols. POMC 2002, October 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: 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 – Implicit source routing

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, –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.