Joint DTN / SOIS Meeting
description
Transcript of Joint DTN / SOIS Meeting
© 2009 The MITRE Corporation. All rights reserved.
Joint DTN / SOIS Meeting
April 22, 2009Colorado Springs, CO
© 2009 The MITRE Corporation. All rights reserved.
Page 2
Agenda
■ Current state of DTN– DTN Picture– RFCs– Implementations
■ DTN2■ ION
– NASA DTN-for-2010 program
■ Current State of SOIS
© 2009 The MITRE Corporation. All rights reserved.
DTN as an Overlay Network
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Application
DTN
TCP
IPv6
Ethernet
UTP
DTN
TCP
IPv6
ATM
DS-1
IPv6
Ethernet
UTP
Onboard NetworkTerrestrial Wired Network
LTP
Encap
TC/TM
Application
DTN
Spacewire
DTNGateway
Long-HaulSpace Link
DTN
LTP
Encap
TC/TM Spacewire
DTNGatewayApplication
DTN
Transport
Network
Link
Physical
IP Router
ATM
DS-1
■ 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)
© 2009 The MITRE Corporation. All rights reserved.
■ 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
DTN Info
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DTN Protocols
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Bundles Built up out of Blocks
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Primary Bundle Block
Payload Block
Other Block (s)
Address information (source, dest, …),treatment flags, QoS marking, creation time, lifetime
Other capabilities, e.g. security, extended QoS markings, metadata describing the payload, at-most-one-of-this-kind
The application-layer payload
© 2009 The MITRE Corporation. All rights reserved.
Primary Bundle Block
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Primary BundleBlock
Version (1 byte) Bundle Processing Control Flags (SDNV)
Block length (SDNV)
Destination Scheme Offset (SDNV)
Destination SSP Offset (SDNV)
Source Scheme Offset (SDNV)
Source SSP Offset (SDNV)
Report-To Scheme Offset (SDNV)
Report-To SSP Offset (SDNV)
Custodian Scheme Offset (SDNV)
Custodian SSP Offset (SDNV)
Creation Timestamp (SDNV) Creation Timestamp Sequence Number (SDNV)
Lifetime (SDNV) Dictionary Length (SDNV)
Dictionary (Byte Array)
Fragment Offset (SDNV, if fragment) Application data unit length (SDNV, if fragment)
© 2009 The MITRE Corporation. All rights reserved.
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 = bulk01 = normal10 = expedited11 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.
Bundle Status Control Flags
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• 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
© 2009 The MITRE Corporation. All rights reserved.
Primary Bundle Block: Address Information
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Primary BundleBlock
Version (1 byte) Bundle Processing Control Flags (SDNV)
Block length (SDNV)
Destination Scheme Offset (SDNV)
Destination SSP Offset (SDNV)
Source Scheme Offset (SDNV)
Source SSP Offset (SDNV)
Report-To Scheme Offset (SDNV)
Report-To SSP Offset (SDNV)
Custodian Scheme Offset (SDNV)
Custodian SSP Offset (SDNV)
Creation Timestamp (SDNV) Creation Timestamp Sequence Number (SDNV)
Lifetime (SDNV) Dictionary Length (SDNV)
Dictionary (Byte Array)
Fragment Offset (SDNV, if fragment) Application data unit length (SDNV, if fragment)
•C
omm
on s
trin
gs s
tore
d in
dic
tiona
ry w
ith
offs
ets
in h
eade
r.
•R
epor
t-to
not n
eces
saril
y th
e sa
me
as th
e so
urce
.•
Cur
rent
cus
todi
an m
arke
d in
hea
der
© 2009 The MITRE Corporation. All rights reserved.
Primary Bundle Block: Creation Time and Time To Live
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Primary BundleBlock
Version (1 byte) Bundle Processing Control Flags (SDNV)
Block length (SDNV)
Destination Scheme Offset (SDNV)
Destination SSP Offset (SDNV)
Source Scheme Offset (SDNV)
Source SSP Offset (SDNV)
Report-To Scheme Offset (SDNV)
Report-To SSP Offset (SDNV)
Custodian Scheme Offset (SDNV)
Custodian SSP Offset (SDNV)
Creation Timestamp (SDNV) Creation Timestamp Sequence Number (SDNV)
Lifetime (SDNV) Dictionary Length (SDNV)
Dictionary (Byte Array)
Fragment Offset (SDNV, if fragment) Application data unit length (SDNV, if fragment)
•Ti
mes
tam
ps a
nd ti
me-
to-li
ve a
llow
bu
ndle
s to
be
purg
ed fr
om th
e ne
twor
k w
hen
no lo
nger
nee
ded.
© 2009 The MITRE Corporation. All rights reserved.
■ 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)
About Time
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© 2009 The MITRE Corporation. All rights reserved.
+-----------+-----------+-----------+-----------+ |Block type | Block processing ctrl flags (SDNV)|+-----------+-----------+-----------+-----------+| Block length (SDNV) |+-----------+-----------+-----------+-----------+/ Block body data (variable) /+-----------+-----------+-----------+-----------+
06 5 4 3 2 1 0+-+-+-+-+-+-+-+| Flags |+-+-+-+-+-+-+-+Block Processing Control Flags Bit Layout0 - 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.
Extension Blocks
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NASA DTN-for-2010 Program
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© 2009 The MITRE Corporation. All rights reserved.
Deep Impact Network Experiment (DINET)
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© 2009 The MITRE Corporation. All rights reserved.
DTN Experimentation Network
GRCEVAION
JSCRoverION
GSFCW. Sands
ION
GSFCL. Relay
ION
JSCAltairION
MSFCMCC / POCC
DTN2/[TCP|UDP]JPLData ConsumerDTN2/[TCP/UDP]
APLData Consumer
ION
250ms: 128kbps [>100M
bps]
100ms : 72/k/192k
BP / UDP
20ms: 10Mbps
BP / UDP
BPLTPUDP
BPLTPUDP
JPLAthleteDTN2
BP / UDP
BP / TCP 0:0 0:0
0:020ms :
10Mbps
BPLTPUDP
BPUDP
EIDs: dtn://eva/*
EIDs: dtn://athlete/*
EIDs: dtn://rover/* EIDs: dtn://altair/* EIDs: dtn://relay/*
EIDs: dtn://whitesands/*EIDs: dtn://msfc/*
EIDs: dtn://aplsci/*
EIDs: dtn://jplsci/*
© 2009 The MITRE Corporation. All rights reserved.
■ Network Management■ Time Synchronization■ Routing
Protocol Mechanisms
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DTN Research Group
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Naming Semantics
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