Download Mapping of scalable RDMA protocols to ASIC/FPGA platforms

FPGA/ASIC Cores for
Interplanetary Internet Applications
Yosef Gavriel Tirat-Gefen, PhD
Senior Member IEEE
Member of ACM, Internet Society (IPNSIG)
Affiliations:
Staff Fellow at the
Center for Devices and Radiological Health (CDRH) / FDA, Rockville, MD
Applied Physics Graduate Program
Dept. Physics and Astronomy
George Mason University, Fairfax, VA
[email protected]
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Presentation Overview
• Motivation
• The interplanetary internet (IPN)
• Bundle based protocols
• CCSDS protocols
• Adapting CCSDS Protocols for IPN
• Work Plan
• Current results
• Conclusion
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Motivation
Very long
delay
Mars / Asteroid
Repeater
Enabling extremely long delay/intermittent
communication
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Motivation
Link to
Earth –
very long
delay
Repeater
Short distance
communication
links
Supporting Manned or Robotic Missions
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Additional Applications
• Delay Dependent Networks
• Sensor Networks
• Military Tactical Networks
• National Emergency Communication
Infrastructure
• 24/7 Health Monitoring of Remotely Located
Patients
• Mobile Medical Networks
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Traditional TCP/IP Networking
Application/O.S.
Application/O.S.
TCP
TCP
Layer 3 (IP)
Layer 2 (MAC)
Layer 1 (PHY)
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Router
Layer 3 (IP)
Layer 3
Layer 3
Layer 2 (MAC)
Layer 2
Layer 2
Layer 1 (PHY)
Layer 1
Layer 1
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Limitations of TCP/IP Networking
• Performance breaks down for links with long delays or intermittent
communication.
• Timeout limitations.
• Memory requirements are huge for long delay round trips.
• Routing algorithms (e.g. BGP) are based in TCP. Routing would
use almost all bandwidth available in an interplanetary link.
• Not suitable for asymmetric communication links, e.g.
telemetry/command.
• Not designed for links with high bit error rates (BER).
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The Interplanetary Internet (IPN)
• Interplanetary Internet Special Interest Group (www.ipnsig.org)
established in September 1999.
• Goal is to develop networking standards for deployment in deep
space missions, e.g.:
• To allow sharing of resources among different missions.
• To establish satellite repeaters to support a future manned
mission to Mars.
• Part of research effort in delay dependent networking (DTN).
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IPN Key Technologies
• Interplanetary Gateways.
• Interplanetary Backbone.
• Security
• Power aware networking (e.g. routing algorithms)
• Coding techniques for error detection and recovery
• CCSDS protocols evolved for interplanetary deployment
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Bundle Protocols
Application/O.S.
Application/O.S.
Transport
Layer 3 (Network)
Layer 2 (MAC)
Layer 1 (PHY)
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Bundle
Bundle
Bundle
Transport
Transport
Transport
Layer 3
Layer 3
Layer 3 (Network)
Layer 2
Layer 2
Layer 2 (MAC)
Layer 1
Layer 1
Layer 1 (PHY)
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Key features in Bundle Networking
• Applications send and receive bundles instead of transport streams.
• Creates an illusion of an end-to-end connection. Support of
intermittent links.
• Custody of data is passed along intermediary nodes in the path
between source and destination.
• Source does not need to wait for a ACK from destination to release
buffer space.
• Security is also enforced by the bundle layer.
• IPN addressing is divided in regions. Each region is a standard
internet. Bundles are exchanged in region gateways.
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CCSDS Protocols
• Consultative Committee for Space Data Systems - CCSDS
• Suite of protocols for space missions and satellites applications
• Standards for telemetry (TM) and telecommand (TC).
• Deployed by more than 155 missions so far.
• File Transfer Delivery Protocol (CDFP) is becoming the baseline
for IPN development.
• CCSDS standards for link layer and data coding can be evolved for
interplanetary deployment.
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CCSDS protocol layers
Running
on a
CPU
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Application Layer
SCPS-FP (File transfer)
SCPS-TP (Transport)
SCPS-SP (Security)
SCPS-NP (Network)
TM – Data Link TC - Data Link
TM-Coding
TC-Coding
RF and Modulation (PHY)
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Suitable for
software
implementation
Suitable for
FPGA/ASIC
and off-theshelf PHY
chips
Tirat-Gefen
FPGA/ASIC Cores for IPN
• Coding layer = Channel Coding and Synchronization
• Link Layer = Space Data Link Protocol
• Coding and link layer standards are suitable for FPGA/ASIC
implementation.
• Advantages in Low Power consumption and performance.
• Safety and correctness are essential as these cores may deployed in
manned missions.
• These cores should be able to use radiation hard non-volatile
memory in addition to RAM banks.
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Our Work
• A library of major building blocks for the link and coding layers for
use by designers of future IPN hardware.
• Capturing relevant protocols for these layers in SDL – A Formal
Object-oriented Language for Communicating Systems.
• The library contains modules coded in:
- Synthesizable – C (e.g. Handel-C)
- Synthesizable and Behavioral VHDL.
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An open source
IP-core library!
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Proposed Architecture
SCPS-NP (Network) Interface
IP/Firmware
module
TM/TC multiplexing
Rx Memory
controller
Rx Memory
Bank (RAM + Non-volatile)
TM/TC Link Cores
Coding Layer Blocks
Tx Memory
controller
Tx Memory
Bank (RAM + Non-volatile)
PHY
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Data Link Core – Tx Direction
From Network Layer Interface (SCPS-NP)
Virtual Channel Multiplexer
Master Channel Generation
Master Channel Multiplexer
To coding blocks (e.g. Turbo-coding/BCH)
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Data Link Core – Rx Direction
To Network Layer Interface (SCPS-NP)
Virtual Channel Demultiplexer
Master Channel Reception
Master Channel Demultiplexer
From decoding blocks
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Present Status
• Our target devices are Virtex and Actel (Radiation Hard)
FPGAs for now.
• Plan to include other FPGA families later.
• Cores are suitable for low-power applications.
• Full implementation of Link and Coding layers will demand
more than one device for current FPGA technology.
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Conclusion
• The availability of a library of cores for the
future interplanetary internet, supporting its lower
protocol layers, may speed up its deployment.
• These same cores could be adapted to earth for
delay dependent networks (e.g., sensor networks
with intermittent links, mobile medical networks).
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