Lessons Learned in Fast Optical Fabric Design

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Lessons Learned in Fast Optical Fabric Design

• Alberto Leon-Garcia
• University of Toronto
• alberto.leongarcia_at_utoronto.ca

Globecom 2003
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High-Level Design Issues

• Starting Point Clearly-defined role in network
  architecture
• Services
• Scalability
• Growability
• Reliability
• Compactness
• Power Consumption Heat Output
• Cost (Capital Operating)

• 0.99999
• Match or Better Electronic Fabric

• Core Switch
• MPLS
• SONET
• Wavelength

• 128 x 128
• 10 Gbps
• x4 40 Gbps
• xN WDM

• Pay as you grow
• 80 Gbps to 1.28 Tbps

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Fast Optical Switch Design Issues

• Switch Component
• Configuration Time
• Fabric Architecture
• Fabric Control
• Synchronization
• Fault Tolerance

• Many fast switching optical devices
• 1x2, 1x4, 2x2,

• Compactness, switching speed, control electronics

• Loss, Polarization Independence, Wavelength
  dependence

• Multistage Clos? Benes? Strictly non-blocking?
  Rearrangeably nonblocking?

• TDM and Packet switching Fabric scheduler path
  selection

• Fast synchronized fabric setup Fast clock
  acquisition SONET receivers too slow

• Failure Mode, Effects and Criticality Analysis
  (FMECA)

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Design Process
Optical Component
Fabric Architecture
Packaging
High-Level Requirements
Packaging is crucial!!!

• Optical device heat, humidity, voltages
• Electronics Power supply, control signals
• Fiber interconnect

• Fabric modular for growability
• Centralized control fabric blades
• Interblade interconnect

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Design Process
Optical Component
Fabric Architecture
Packaging
High-Level Requirements

• Link Budget
• Number of Stages

• Path to path variability
• Receiver adaptivity

Link Performance Fabric Size
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Design Process
Optical Component
Fabric Architecture
Packaging
High-Level Requirements

• Delay performance

Fabric Tick is Key Parameter

• Bandwidth efficiency speedup
• Power heat

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Areas for Improvement

• Reliability
• Compactness
• Power Consumption
• Cost
• Design Process