Delay Tolerant NetworkEndpoint ID Discussion

David Young - Ohio University IRG david.a.young@gmail.com

Joerg Ott - TKK Netlabjo@netlab.tkk.fi

1Ohio University IRG ~~~ TKK Netlab

Current EID Conventions• Bundle Protocol Specification

– <scheme> : <scheme-specific part>– both fields limited to 1023 bytes– dtn:none -- null endpoint

• DTN2– dtn: <hostname>.dtn [/ <appname> ] [.<id>]– <id> used is the OS PID (see dtnping)– multihoming unsupported

• ION– ipn: <element_number> : <service_number>– <service_number> 0 reserved for admin bundles– multihoming unsupported

Ohio University IRG ~~~ TKK Netlab 2

Current Routing Conventions• DTN2– Route aggregation via wildcard *

• <prefix>*• route add dtn://mybox.dtn/* link_tcp• dtn://mybox.dtn/dtnping match• dtn://mybox.dtn/dtnsend.43233 match

• ION– Implicit aggregation of service_number– Only element_number considered.

• a plan 2 router x tcp/amroc.jpl.nasa.gov:5001• ipn:2.0 match• ipn:2.10 match

Ohio University IRG ~~~ TKK Netlab 3

EID issues• Multiple Implementations– ion, dtn2 ...– Different schemes

• Naming Collisions– dtn://linksys.dtn

• Crossing Dumb(er) Nodes– Intermediate nodes don't understand your scheme

• Application Context– How much application context goes in the EID?– Where else could it go?

Ohio University IRG ~~~ TKK Netlab 4

Some Solutions

• New schemes for every application– mailto: ftp: ...– Allows routing/load balancing by application– Demux at bundle layer, not application– Explicit nature avoids indirection/lookups

• Application-hints extension block

Ohio University IRG ~~~ TKK Netlab 5

Some (more) Suggestions• Disclaimer• Modify dtn:// for more general use

– Use FQDNs if dns is possible• Reduces likelihood of collision• Makes routing easier on terrestrial internet

– Continue * notation, but reverse order of FQDN• dtn://edu.ohiou.cs.myhost• allows more aggregation, especially at gateway

• New scheme for general use.– Lowest common denominator of EID on all platforms– No application data/optional application data

• Multiple schemes in same EID for interoperability– dtn://dtnnetwork.ohiou.edu.dtn/:ipn:1.0– Networks that do not understand each other's schemes

Ohio University IRG ~~~ TKK Netlab 6

References

• Application Conventions for Bundle-based Communications– draft-ott-dtnrg-appl-00

• Architectural Considerations for the use of Endpoint Identifiers in Delay Tolerant Networking– draft-eddy-dtnrg-eid-00

• Bundle Protocol Specification– rfc5050

Ohio University IRG ~~~ TKK Netlab 7