Project Stratus - Juniper lays out flat network roadmap

From its position in the switching trenches, Juniper Networks has planned not one, but two ways to flatten legacy three-tier data center networks.

Cisco vs. Juniper

Juniper calls its approach the 3-2-1 data center network architecture, promoting the idea that enterprises can cut one tier out of their data center networks today and, ultimately, another.

The result will be the flattest of all flat networks - a single layer operating as one giant switch.

Juniper shared that ultimate vision, called Project Stratus, almost two years ago, but products aren't expected till 2011.

A two-tier fabric

In the meantime, enterprise network planners who see value in a flatter architecture can take advantage of a two-tier fabric using Juniper's Virtual Chassis technology.

Applied at the access layer, Virtual Chassis technology allows up to 10 EX 4200 top-of-rack switches to operate and be managed as a single logical switch comprising hundreds - 480 in the case of the EX 4200 - of Gigabit Ethernet ports.

Juniper also will have Virtual Chassis technology available on the EX 4500, a 48-port 10G Ethernet switch that will be available later this year or early next, says Calvin Chai, a director of enterprise marketing at Juniper.

Enterprises can mix and match EX 4200 and 4500s, which also will support Converged Enhanced Ethernet and Fibre Channel over Ethernet (FCoE) for storage convergence, in the same Virtual Chassis fabric.

"You still have your physical devices, but instead of using the traditional chassis-based model with a single chassis sitting in a rack and slotting in modules for ports, you can have these one-rack unit servers distributed throughout the data center. You can extend the Virtual Chassis fabric across floors, buildings or in the same rack using fiber connections," says Chai, noting a distance limitation of 50 kilometers.

"And, you don't have to have 10 different uplinks from each of those switches. You just need one uplink because it behaves as one logical switch, so you're saving on port density and can collapse the core and aggregation layers - you simplify the network as you scale it up," he adds.

"Juniper does have this nice, interesting twist with how it's pulling off this two-tier architecture by making it look like one machine," says Robin Layland, head of Layland Consulting, which specializes in network architecture and strategy for enterprise customers.

A single network hop

Further reducing complexity and bolstering performance would come with even more streamlining of the data center network architecture, Chai says. Juniper hasn't disclosed Stratus project details, but the goal is to collapse to a single layer that will provide connectivity from any point to any other point in a data center with one processing hop, he says.

And don't be fooled by the "3-2-1" name, Chai says. Enterprises do not need to flatten the network progressively. An enterprise running a large three-tier data center network could go straight from there into a Stratus fabric, he says.

"I don't dare use the word 'FDDI,' but it does sound like Juniper is planning to interconnect all these machines together and, in effect, form a super bus loop over the data center. Data would travel around the bus until the right machine pulls it off," says Layland, referring to an obsolete token-based networking technology. "We definitely don't want to say 'FDDI,' but you can ask all the same sorts of questions and bring up the same issues using new terms if we're essentially talking about a ring architecture."

"One tier, two tier - are we talking 10-minute abs or seven-minute abs? It's really all up to the flexibility of the customer," says John Turner, director of networks and systems at Brandeis University, in Waltham, Mass., which is currently evaluating how best to handle a data center network refresh coming in 2011.

Juniper has made Brandeis' short list of choices, as has Cisco. But Turner says he's made no final decision on how best to flatten the network in support of increased virtualization. Storage convergence is on his mind, too, but not a burning issue at this point.