1. DTNs Delay Tolerant Networks

2. Fall, Kevin. Intel Research, Berkeley. SIGCOMM 2003 Aug25, 2003. A Delay- Tolerant Network Architecture for Challenged Internets. August 2003. Warthman, Forrest. Delay Tolerant Networks (DTNs): A Tutorial. March 2003. Jones, Evan P.C. Practical Routing in Delay- Tolerant Networks. Papers

3. TCP/IP service model works great with connected, reliable networks. Several implicit assumptions: – E2E Path exists (Connected) – RTT small – Drop probability is small – Symmetric Data Rates Introduction

4. The TCP/IP Model

6. Terrestrial Mobile Networks Exotic Media Networks Military Ad Hoc Networks Sensor Networks Challenged Networks

7. Terrestrial Mobile Network Example

8. Path and Link Characteristics High Latency Low Data Rate Disconnection Long Queuing Times Challenged Networks

9. End System Characteristics Limited Longevity Low Duty Cycle Operation Limited Resources Challenged Networks

10. Fix TCP/IP? Link Repair Approach Performance Enhancing Proxy (PEP) Protocol Boosters Proxies Electronic Mail US Postal Service Message Based Overlay Architecture Bundling Ideas

11. Store and Forward Nodes use persistent storage to store messages indefinitely Forward when able to do so, Otherwise, wait

12. DTN

13. DTN Regions A DTN is a network of networks These “sub” networks are called Regions Each Region has a unique Region ID that is globally known throughout the DTN DTN Resources are identified by name tuples (Region ID, Entity ID) DTN Gateways are members of two or more regions and handles all communication between regions

14. Overlay: The Bundle Layer

16. DTN Nodes

17. Custody Transfers Hosts store bundles in persistent storage until custody can be passed or TTL expires Hosts request custody transfer to next-hop node Next-hop node has option to accept custody Local copy removed upon transfer of custody Only nodes supporting CT can accept custody Transport Layer protocol terminates upon acceptance of custody

18. Custody Transfers

19. Overlay: The Bundle Layer

20. DTN Gateway

21. DTN vs. TCP/IP

22. Names and Addresses

23. Security

24. IPN (InterPlanetary Network) Example

25. Step 1: Bundle Creation at Source

26. IPN (InterPlanetary Network) Example Step 2: Transmission by Source

27. IPN (InterPlanetary Network) Example Step 3: First Hop Bundle Processing/Forwarding

28. IPN (InterPlanetary Network) Example Step 4: Second Hop Bundle Processing/Forwarding

29. IPN (InterPlanetary Network) Example Step 5: Bundle Reception at Destination

30. THE END Questions?