However much the Infiniband crowd talks up their platform as the foundation for the unified fabric, the fact is that the vast majority of enterprises are deeply invested in Ethernet and is likely to leverage that investment for as long as possible.
But while it doesn't look as if Ethernet will catch up to Infiniband in raw throughput any time soon, system developers are moving forward on a number of fronts to improve efficiency and reliability and to forge ties to other network formats.
The most obvious format, of course, is Fibre Channel. But even while Fibre Channel over Ethernet (FCoE) nears the end stage of the ratification process, work is moving ahead to put the two protocols on the same hardware, if not the same fabric. QLogic, for example, recently shipped a combined Ethernet/Fibre Channel quad port system for the Sun Blade 6000 and 8000 platforms. The QEM3472 ExpressModule combines 4G Fibre Channel and 1G Ethernet, effectively doubling the number of ports available to users.
Another limiting factor for Ethernet is its poor record when it comes to predictability and packet loss. If there's one thing sure to drive enterprise users up the wall, it will be watching their work disappear into the ether whenever it's sent to storage or to other end points. Unfortunately, it looks as if a solution could be a long time coming. The Ethernet Alliance only this week got around to naming a subcommittee to look into the problem. The group says it will reach out to the IEEE to coordinate with their FCoE and data center bridging and congestion efforts.
Ethernet's chief advantage is that it already extends beyond the enterprise into the wide area. And it's here that the current 10 Gb limitation no longer applies. Juniper Networks recently introduced a new set of dense port concentrators (DCPs) to its carrier-class MX routers, one of which delivers 20 Gbps over the long haul. The company also provides a multi-rate device that can carry both 1 and 10 GbE, as well as a low-rate unit for 10/100/1000 use.
With fully unified fabrics still a way into the future, the Ethernet community has time to shore up its technology (although so do the Infiniband backers). At the moment, it looks as if there is healthy demand for Ethernet systems. IDC reports that sales of Layers 2-7 switches, routers and WLAN equipment likely will double the pace of server and storage growth for the coming year.
If the decision had to be made today between Ethernet and Infiniband, I would have to side with Infiniband as the preferred fabric. It's faster, more reliable and, arguably I admit, no more expensive than 10 GbE. Fortunately for Ethernet, it has a large installed base and some high-powered backers in Cisco and Brocade. The showdown is coming, but right now all the action is in training camp.