David B. Johnson

1
DSR Status Update

• David B. Johnson
• Rice University
• Department of Computer Science
• http//www.monarch.cs.rice.edu/
• dbj_at_cs.rice.edu

55th IETF
2
DSR Dynamic Source Routing Protocol

• Divides routing problem into two parts
• Route Discovery only try to find a route to some
  destinationwhen you dont have one and need one
• Route Maintenance only while youre 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

3
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

4
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.

5
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.

6
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

7
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,
  ISPAN99, 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

8
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.