"It’s a more complicated arrangement now," he says, compared to other fabric architectures. While QFabric delivers significantly lower latency than other fabric solutions, it’s a more involved installation than those of competitors. "You’ve got to be willing to make the jump to this non-conventional way of building a switch infrastructure," he adds.
But Juniper explains that QFabric is not an all-or-nothing proposition, nor is its adoption as weak as critics say.
The QFX 3500 switches began shipping in March, but the Interconnect and Fabric Director components didn’t become available until late September of last year, says Dhritiman Dasgupta, senior director of product marketing at Juniper. The switches can operate as standalone switches, but it is only when combined with the Interconnect and Fabric Director that it becomes a QFabric installation--a fabric of up to 6,144 ports. That being the case, QFabric as a whole has been available only for about two full quarters.
Because a customer can add QFX 3500 switches to their data center and then add the other components to make it QFabric, "it provides a very nice migration path," says Dasgupta.
"We don’t come in and say you have to buy this 6,000-port fabric to prepare for this very large environment," adds Denise Shiffman, a VP of product marketing at Juniper. "When you hit a certain amount of [switch] density you can move that into ... the fabric and grow that fabric incrementally."
And despite critics’ claims that QFabric is all pitch and no close, it does have some paying, and named, customers, she says. Juniper lists Sabey Data Centers, a hosting service provider, and Bell Canada, Canada's largest telco, as users of QFabric, plus others that are confidential. Shiffman acknowledges that these are partial deployments of QFabric and not in production environments. The company also has several customers running just the QFX switches for now, "[though] they see it as an on-ramp to the rest of the QFabric family," she says.
Nonetheless, once you go full QFabric, it’s hard to go another way, notes Jason Nolet, VP of data center and enterprise networking at Brocade. "Where you might see Juniper QFabric as being a highly proprietary interconnect ... we try to remain as open standards-based as possible."
Brocade, like industry leader Cisco, bases its fabric technology on TRILL, and began shipping its VDX line of switches in late 2010 and early 2011. Its secret sauce is "virtual cluster switching," which provides the ability to connect a number of VDX switches into whatever arrangement the customer chooses.
