Panel - Is It Time to Switch to Optical Interconnects? Joel Goergen – Cisco Systems, Inc. Version r2 Open Server Summit November 2014 Santa Clara, CA 1 Open Server Summit November 2014 – Santa Clara, CA Fabric 100 Gb/s PAM4 CDPPI 0 X ?? Tb/s Optic Engine PPU /NPU DIE Optic Engine 0 X 400 Gb/s 4 by 100G CDPPI 100 Gb/s PAM4 100 Gb/s PAM4 0 100 Gb/s PAM4 100 Gb/s PAM4 3 0 400 Gb/s 4 by 100G CDPPI 100 Gb/s PAM4 100G SERDES building block 2 100G SERDES building block Open Server Summit November 2014 – Santa Clara, CA 3 • S E R D E S C o R e T y p e 3 N R Z P A M 4 N R Z P A M 4 • P A M 4 • 1 – NRZ for CDPPI / C2M / C2C • Long term covering C2F with PAM4 and covering USR with NRZ • Might be a challenge for C2M • Preserves SI test equipment and strategies in the lab • Optics can stay NRZ • Long term covering C2F with PAM4 and covering USR with NRZ • Compatibility between C2C and C2F • Complicates test equipment and SI strategy in some cases • Optics can stay NRZ • Compatibility across all reaches • Changes test equipment and SI strategies, but not sure the extent • Optics has to move to PAM4 unless a conversion step is specified 2 – NRZ for CDPPI / C2M and PAM4 for C2C 3 – PAM4 for CDPPI / C2M / C2C Open Server Summit November 2014 – Santa Clara, CA • PAM4 for ALL S E R D E S C o R e T y p e 4 • Compatibility across all reaches P A M 4 • Changes test equipment and SI strategies, but not sure the extent • Optics has to move to PAM4 unless a conversion step is specified Open Server Summit November 2014 – Santa Clara, CA S E R D E S C o R e T y p e 5 P A M 4 • PAM4 for CDPPI / USR / XSR • No other reach is likely • Must be optical for VSR / MR / LR Reaches • Unless there is a significant leap in modulation or FEC, copper is done here Open Server Summit November 2014 – Santa Clara, CA • Copper may hold its own up to 100 Gb/s using PAM4. • There might be C2M / VSR reach for 200 Gb/s using PAM4. • There may exist opportunities for incredibly short reaches up to 400 Gb/s. • After 400 Gb/s, its “Plan B”. • To be fair – in July 2005, I said the copper limit was 25 Gb/s. Today, I think we can achieve 100 Gb/s, with a few 400 Gb/s reach opportunities. Open Server Summit November 2014 – Santa Clara, CA Thank you! 7 Open Server Summit November 2014 – Santa Clara, CA