With rumors still swirling that it will make its move into the server market, Cisco Systems continued its data center network blitz this week by expanding its family of Nexus switches. The new devices are aimed at helping network engineers to design high-density data center network fabrics that are optimized for server virtualization.
"The big overarching theme here is that virtualization has changed the way people design networks in data centers," said Zeus Kerravala, senior vice president for Yankee Group. "And what you see Cisco rolling out with Nexus is a line of equipment that is designed for virtual environments."
Cisco added two new switches -- the Nexus 5010 and the Nexus 7018 -- and it also introduced the Nexus 2000, a top-of-rack device that enables a hybrid approach between the top-of-rack and end-of-row data center network architectures.
The Nexus 5010, a variation on earlier 5000 class switches, consolidates 28 ports of 10 Gigabit Ethernet (GbE) into a 1U form factor that can be deployed in top-of-rack situations. The Nexus 7018, a larger cousin of the 7000 switch, is an 18-slot chassis that can offer up to 768 GbE or 512 10 GbE port density, plus 48 ports of 1 Gb Fiber, offering a high-end switch that can serve in the core of very large data centers and supercomputing environments.
Top of rack vs. end of row: Best of both in data center networks
The Nexus 2000 Fabric Extender offers a new approach to networking in the server access layer. The 2000 sits at the top of a server rack and provides connectivity for the servers, but it doesn't do any independent switching. Instead, it links back to an end-of-row switch, such as the Nexus 5000 or 7000 or the Catalyst 6500, which manages switching. The Nexus 2000 acts as an extension of that end-of-row switch.
"[The Nexus 2000] looks like a switch, but it does not behave like a switch," said Dante Malagrino, Cisco director of product marketing for data center emerging technology. "You preserve the advantages of a top-of-rack cabling architecture, which many customers are looking at to simplify and rationalize their cabling in data centers. But you don't give up the benefit you get from end-of-row architecture in terms of reduced point management."
The Nexus 2000 literally extends the network fabric approach of Nexus switches out of an end-of-row switch and delivers it to multiple racks of servers. This is important because groups of virtual servers on physical host devices tend to demand a lot more bandwidth.
"This coincides with the server consolidation that is happening with virtualization," said Andreas Antonopoulos, vice president and founding partner of Nemertes Research. "That has led to organizations juggling with the decision of whether to have a switch at the top of each rack or whether they aggregate to a switch at the end of the row. What this offers is a kind of compromise between the two."
Kerravala said the network fabric approach of Cisco's Nexus line, and of other vendors such as Woven Systems, makes a network more efficient in transferring information from these virtual servers.
"The whole concept behind Nexus is that it creates a fabric," he said. "Storage networks work on a fabric, where any point on the fabric can connect to any other point on the fabric. In networking, that is usually not the case. You use a spanning tree. It always chooses the same path -- and if that path is not available, it chooses a different path. In order to create shorter paths, you have to use more cables. Nexus brought fabric connectivity to networking. What the 2000 does is allow you to extend that fabric outside the Nexus box to the rack itself. In a network where you're doing any kind of virtual machine mobility, you want the whole network to act like a fabric and not like a traditional Layer 2 and Layer 3 network."
Easing data center network management
The Nexus 2000 also reduces management overhead for networking organizations. Since the device is simply an extension of an end-of-row switch, a network administrator can reap the benefits he would find by having a switch at the top of each rack without suffering the headache of having to manage each individual rack switches. Instead he can manage the networks of multiple server racks through the management console of one end-of-row switch.
"Architecturally, what we're seeing in the enterprise is a consolidation of network devices to reduce the number of management points, the number of patches, the number of updates, and the number of configurations where things can go wrong," Antonopoulos said.
Catalyst 6500 gets Nexus-flavored upgrades
Malagrino said Cisco is also upgrading its Catalyst 6500 switches, through a combination of hardware and software updates, with some of the features offered in the Nexus family of switches. These features include the in-service software upgrade feature, where switches can receive upgrades through service virtualization that won't affect switch availability. Cisco is also offering several 10 GbE interconnect options and some high-performance encryption technology.
"Catalyst has a huge installed base, and I think it would be very bad for [Cisco] to forget about that product," Kerravala said. "[Cisco needs] to do this to create some sort of migration path for customers, because they can deploy those features in currently existing 6500s, then when they're looking to scale, they can migrate over to Nexus."
Next stop, 'California' blade servers
The data center will be a major battleground for network vendors in the coming years. Cisco, like many of its rivals, recognized this years ago. The company has invested $1 billion in the development of its Nexus line. A year after the first Nexus 7000 switches were announced, that investment is starting to pay off.
"We're gaining traction with this," Malagrino said. "We have more than 250 customers that have already selected the Nexus family to run in their data centers."
Kerravala said Cisco's Nexus strategy is building toward the company's next highly anticipated announcement: its first blade server, code-named California. Rumors have swirled that such an announcement could be made this quarter.
"[The server] is an important part of what Cisco is doing," Kerravala said. "Virtualization has changed the way people are designing networks. And every time you modify the virtual environment, you modify the network. So in theory, you would want the network and the compute environment to work very closely together, and I think that's the whole premise behind California."
Indeed, a server product would help Cisco respond to a renewed assault from HP, whose ProCurve division launched its first line of data center networking switches this week. HP intends to leverage its strong data center presence with storage, server and management technologies to help it chip away at Cisco's data center networking dominance. Kerravala said Cisco views HP as a very real threat.
"The one thing HP has as an advantage is its channel, which is well embedded into IT guys," he said. "HP ProCurve has an advantage in a channel which by and large lives in the data center. I don't think ProCurve products are quite where Cisco is, but from a channel perspective, it's advantage HP."
Let us know what you think about the story; email: Shamus McGillicuddy, News Editor