1 / 18

Joint DTN / SOIS Meeting

Joint DTN / SOIS Meeting. April 22, 2009 Colorado Springs, CO. Agenda. Current state of DTN DTN Picture RFCs Implementations DTN2 ION NASA DTN-for-2010 program Current State of SOIS. LTP. Encap. TC/TM. DTN as an Overlay Network.

mireya
Download Presentation

Joint DTN / SOIS Meeting

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Joint DTN / SOIS Meeting April 22, 2009 Colorado Springs, CO

  2. Agenda • Current state of DTN • DTN Picture • RFCs • Implementations • DTN2 • ION • NASA DTN-for-2010 program • Current State of SOIS

  3. LTP Encap TC/TM DTN as an Overlay Network • Convergence Layers: the “glue” that interfaces DTN to lower-layer protocols such as TCP, UDP, Ethernet, BlueTooth • Convergence layers just move data from DTN node to DTN node • Routing happens at the DTN layer (choosing the next DTN layer router) DTN Gateway DTN Gateway Application Application Application DTN DTN DTN DTN DTN Transport TCP TCP IP Router Network IPv6 IPv6 LTP IPv6 Link Ethernet ATM Encap Ethernet ATM Physical UTP DS-1 TC/TM Spacewire Spacewire UTP DS-1 Long-Haul Space Link Terrestrial Wired Network Onboard Network

  4. DTN Info • Requests for Comments • Architecture (RFC4838) • Protocol Specification (RFC5050) • Review of the above by JAXA • DTN Implementations • DTN2 Reference Implementation • Interplanetary Overlay Network (ION) Implementation • DTN interfaces to the rest of the system • Applications (API) • Lower layers • DTN has a notion of ‘Convergence Layers’ for transporting DTN bundles across underlying technologies (TCP, UDP, LTP) • Storage • DTN really wants to commit data that cannot be forwarded to persistent storage

  5. DTN Protocols

  6. Bundles Built up out of Blocks Primary Bundle Block Address information (source, dest, …), treatment flags, QoS marking, creation time, lifetime Other Block (s) Other capabilities, e.g. security, extended QoS markings, metadata describing the payload, at-most-one-of-this-kind Payload Block The application-layer payload

  7. Primary Bundle Block

  8. Bundle Status Control Flags 2 1 0 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Status Report| RESERVED|COS| General | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 0 -- Bundle is a fragment. 1 -- Application data unit is an administrative record. 2 -- Bundle must not be fragmented. 3 -- Custody transfer is requested. 4 -- Destination endpoint is a singleton. 5 -- Acknowledgement by application is requested. 6 -- Reserved for future use. The bits in positions 8 and 7 constitute a two-bit priority field : 00 = bulk 01 = normal 10 = expedited 11 is reserved for future use. 9 -13 -- reserved for future use. 14 -- Request reporting of bundle reception. 15 -- Request reporting of custody acceptance. 16 -- Request reporting of bundle forwarding. 17 -- Request reporting of bundle delivery. 18 -- Request reporting of bundle deletion. • Can be used to track the progress of a bundle in the network • Signals can be generated but not forwarded (if no route exists) – pull accounting information only if there’s a network error

  9. Primary Bundle Block: Address Information • Common strings stored in dictionary with offsets in header. • Report-to not necessarily the same as the source. • Current custodian marked in header

  10. Primary Bundle Block: Creation Time and Time To Live • Timestamps and time-to-live allow bundles to be purged from the network when no longer needed.

  11. About Time • The combination of (sending EID, Creation Timestamp, and Creation Timestamp Sequence Number) uniquely identifies a bundle • Loose time synchronization among nodes is required to support the time-to-live notion • Loose, like, to within 10s of seconds, e.g. • Some notion of using a countdown time instead of (creation, lifetime)

  12. Extension Blocks +-----------+-----------+-----------+-----------+ |Block type | Block processing ctrl flags (SDNV)| +-----------+-----------+-----------+-----------+ | Block length (SDNV) | +-----------+-----------+-----------+-----------+ / Block body data (variable) / +-----------+-----------+-----------+-----------+ 0 6 5 4 3 2 1 0 +-+-+-+-+-+-+-+ | Flags | +-+-+-+-+-+-+-+ Block Processing Control Flags Bit Layout 0 - Block must be replicated in every fragment. 1 - Transmit status report if block can't be processed. 2 - Delete bundle if block can't be processed. 3 - Last block. 4 - Discard block if it can't be processed. 5 - Block was forwarded without being processed. 6 - Block contains an EID-reference field.

  13. NASA DTN-for-2010 Program

  14. Deep Impact Network Experiment (DINET)

  15. DTN Experimentation Network JPL Athlete DTN2 20ms: 10Mbps BP UDP EIDs: dtn://athlete/* BP LTP UDP BP LTP UDP GRC EVA ION JSC Rover ION JSC Altair ION GSFC L. Relay ION BP / UDP 0:0 20ms : 10Mbps EIDs: dtn://eva/* EIDs: dtn://rover/* EIDs: dtn://altair/* EIDs: dtn://relay/* 100ms : 72/k/192k BP LTP UDP 250ms: 128kbps [>100Mbps] APL Data Consumer ION BP / UDP EIDs: dtn://aplsci/* MSFC MCC / POCC DTN2/[TCP|UDP] GSFC W. Sands ION BP / UDP 0:0 0:0 JPL Data Consumer DTN2/[TCP/UDP] BP / TCP EIDs: dtn://msfc/* EIDs: dtn://whitesands/* EIDs: dtn://jplsci/*

  16. Protocol Mechanisms • Network Management • Time Synchronization • Routing

  17. DTN Research Group

  18. Naming Semantics

More Related