Lessons Learned in Fast Optical Fabric Design

1. Lessons Learned in Fast Optical Fabric Design Alberto Leon-Garcia University of Toronto alberto.leongarcia@utoronto.ca Globecom 2003

2. 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

3. 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 • 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) • Loss, Polarization Independence, Wavelength dependence

4. Design Process Optical Component Fabric Architecture Packaging High-Level Requirements • Fabric modular for growability • Centralized control + fabric blades • Interblade interconnect Packaging is crucial!!! • Optical device: heat, humidity, voltages • Electronics: Power supply, control signals • Fiber interconnect

5. 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

6. Design Process Optical Component Fabric Architecture Packaging High-Level Requirements • Delay performance Fabric Tick is Key Parameter • Bandwidth efficiency & speedup • Power & heat

7. Areas for Improvement • Reliability • Compactness • Power Consumption • Cost • Design Process