Short reach chips to drive low cost 10G switches

Short reach chips to drive low cost 10G switches

SANTA CLARA, Calif.--A new class of short reach 10 Gbit/second Ethernet chips is on way, opening the door to smaller, cheaper, lower power switches for data centers.

The so-called 10GBase-T SR (short reach) physical layer chips could cut power consumption from 4W to 1.5W per port. That opens the door to 60W 10G top-of-rack switches for data centers, replacing 250W systems used today. The power reductions enable use of lower cost power supplies and other components so systems can be closer in size and cost to today’s gigabit switches.

The key change is the new physical-layer chips do not have to support the full 100 meter distance of the 10GBase-T standard. Instead they can automatically negotiate a connection, optionally supporting 100G or shorter distances.

Today’s data centers typically only need five meter links inside a rack and 30 meters to an aggregation switch. “The IEEE 10GBase-T standard really overshot [distance requirements] and a new 40G effort realized that is and may back off,” said Dan Dove, a senior director of technology at Applied Micro Circuits Corp., speaking at the Linley Data Center Conference here.

Ethernet standards traditionally supported 100 meters, but “that last 20 meters for 10G became a problem,” he said.

Dove made a short reach proposal to the IEEE 40GBase-T group now starting its work. It aimed to include the 10G generation, specifying optional lengths of 10 and 30 meters and giving vendors an option to not support 100 meters at all for low cost products.

The proposal drew vocal opposition from cable and patch-panel makers. “I didn’t even put it to a vote--we wouldn’t make it--so we will compete in the market,” Dove said.

Vendors have done some work on ad hoc multi-source agreements defining the approach and may create a marketing alliance to promote it. The change can be made to existing chips in firmware, Dove said.

If the work moves forward, “PHY vendors will jump on it and create devices,” said Kamal Dalmia, vice president of sales and marketing at Aquantia, a 10GBase-T vendor on a panel at the conference.

Related stories:

• Debunking 10GBase-T Myths
• 10Gb/s Ethernet and 10GBase-T for the data center

TAG:Physical Layer Chips Applied Micro 10GBase T SR 10GBase T 40GBase T Switches Ethernet Aquantia