New 10G backplane strategies offer promise

摘要

Today, most cards are connected within a rack via a backplane, but the drive toward 10 Gbits/sec has limited the distance such connections can run. While cards that require high-speed connection can be cabled together using fiber or a short span of coax, both the Optical Internetworking Forum (OIF) and the IEEE are examining alternative means to extend the distance two cards can be connected electrically on a 10-Gbit/sec backplane. The problem stems from an increase in input/output capacity; today's systems feature more cards per system and greater capacity per card. Reductions in size and power consumption and increases in the signaling speed of fiber-optic transceivers like the XFP, XPAK, and X2 are driving up the capacity per card. But advances in backplane architectures have not kept pace. Vendors are shipping products based on the XAUI and InfiniBand speeds of 3.125 and 2.5 Gbits/sec, respectively.