Cisco has led the networking industry for a long time. It's shipped more ports into data centers than any other company. And yet, some engineers and experts remain skeptical about Cisco's vision for the future of data center networking. Nowhere is the uncertainty surrounding Cisco's data center architecture more evident than in Gartner's data center networking Magic Quadrant. The analyst firm declined to name a market leader, even though Cisco has more market share than the other companies combined.
The majority of network engineers today have based their careers on building and maintaining Cisco networks. Now, as they think about the future of their data centers, many engineers need to determine whether the vendor's data center architecture can get them to that future.
"The issue with Cisco is that they don't have a coherent vision. It changes on a fairly regular basis. They have overlapping and conflicting sets of solutions," said Mark Fabbi, vice president and lead author of Gartner's data center networking Magic Quadrant. "When you look at Cisco's portfolio, you really have to determine what problem you are solving and that determines what hardware architecture you buy. And it's difficult to migrate between those architectures, as opposed to most of the other vendors on the market where you can start with a hardware approach, and if your architectural requirements change, it's a software load to move from one solution to another."
Cisco has been responding to competitive pressure rather than leading the industry, Fabbi said. The problem goes back to 2008 when Cisco introduced the Nexus 7000, a switch that was a response to Juniper's entrance into enterprise switching -- a pattern that has only continued, he said.
"They introduced low latency [Nexus 3000] switches because of the competitive threat they were seeing from Arista. And they rushed ACI [Application Centric Infrastructure] into the market because of the competitive threat of VMware. They've become a reactive vendor and a reactive vendor isn't a leader."
More than one Cisco data center architecture to choose from
Is Cisco's reactive posture really a problem for network engineers? Fabbi thinks so because it leads to products that are incompatible with the equipment that engineers have already installed in their networks. Product announcements at last year's Cisco Live were a stark example, he said. On the same day that Cisco revealed the Nexus 7700, the next-generation of the Nexus 7000, it also partially lifted the veil on ACI and the Nexus 9500, a new chassis switch that in some ways competes with the Nexus 7700.
ACI, Cisco's data center SDN technology, currently works only with the Nexus 9300 and 9500 series, new switches Cisco announced in conjunction with ACI late last year. At the time, many engineers decried ACI's lack of compatibility and investment protection for older Nexus switches, particularly the expensive Nexus 7000.
"It shows a complete lack of coordinated effort and a lack of insight into what their customer base would have liked to have seen," Fabbi said.
That's not the case, Cisco said. According to Cisco Senior Vice President Soni Jiandani, the company will unveil an initiative at this month's Cisco Live that will allow Nexus 7000, 5000 and 2000 customers to integrate existing technologies into ACI.
"Frankly, Gartner is not qualified to make these statements, because we have not yet announced the investment protection," she said.
Cisco data center architecture suffers from overcrowded portfolio
Regardless of what engineers think of ACI, switches are what matter to most of them. And Cisco has a lot of switches -- some say too many. The Nexus family, for example, has 9500, 7000 and 7700 chassis switches, a 6000 series of spine switches, 9300, 5000 and 3000 fixed-form factor switches and the 2000 fabric extenders. Most of these switch series contain multiple iterations.
"It's created a lot of confusion and it's made customers feel like they can't make the right choice," said Bob McCouch, network architect for a consulting firm.
One of McCouch's clients recently tried to pick a Cisco switch to connect a half- dozen VMware host servers and a NetApp SAN. A reseller proposed two options -- a pair of Nexus 5672s or a pair of Nexus 9328s. The IT organization asked McCouch to help it decide.
"There was a lot of feature parity between them," McCouch said. "Then I looked at it and said, 'Why aren't you looking at the Nexus 3548?' It's a much lower price, even if it's missing a couple of features. Rather than being able to say, 'For this you need product X,' it turned into back-and-forth emails trying to help these guys make a decision. At some point the CIO finally said, 'I just need to pick something because I've spent less time on much bigger purchases in the past.' That was a signal to me that there is too much to figure out here."
Teren Bryson, a consulting systems engineer for a global system integrator, doesn't think the crowded Nexus portfolio presents a problem.
"If you are running data centers and have good partnership with VARs and good people on staff, I think it's pretty easy to plug in to the Cisco roadmaps and figure out what you want to do," Bryson said. "There are a lot of widgets from Cisco, but it's getting more complicated than it used to be to design networks and data centers in general. It's not more confusing, but there is more work involved, and that applies not just to Cisco but other vendors, too."
While some observers see a crowded Cisco Nexus switching portfolio, Cisco argues that it has a cohesive set of products aimed at addressing an extremely large and diverse market.
"If you take a snapshot of the portfolio we have, [it is] cohesive for our customers in the different segments of the market we sell into. Whenever you sell into a multibillion dollar market and you have 70% market share, you have different customers and you have to sell solutions to meet the different types of requirements of those customers," Cisco's Jiandani said. Seven of the 10 largest cloud providers use Nexus switches, she said. Those providers want low-latency, merchant-silicon switches, so Cisco built Nexus 3000 top-of-rack switches. "And as they move to 40 Gb, they will buy the Nexus 9000 merchant-only modular portfolio from us.
"Then there are products like the Nexus 7000, which serves not only as an aggregation device, but also as a data center interconnect device for our commercial customers," Jiandani said. "The Nexus 7000, along with architectures like the Nexus 5000 and the Nexus 2000 fabric extender, are the prevalent designs we have sold into our customers for the last five years."
As mainstream enterprises adopt 10 Gigabit Ethernet (GbE) server connectivity, Cisco is poised to support them, Jiandani said. The Nexus 7000 can be upgraded to support 40 GbE aggregation and the Nexus 9300 can serve as a top-of-rack option, she said. And if an enterprise wants to start dabbling in ACI, it can deploy that technology in new data center pods that can aggregate back into existing Nexus 7000 switches.
"The message I want to give is that there is a step-by-step migration that we are offering our customers as they look to embrace 10 GbE in the access layer," she said.
Gartner's Fabbi remains unconvinced. Many enterprises invested in the Nexus 7000 because they believed it was the strategic platform of the future, much like the Catalyst 6500 once was, he said. The Catalyst 6500 was Cisco's dominant core switch for more than 12 years.
"All of a sudden you look at the Nexus 7000 and after four or five years they felt like the rug was pulled out from under then with the launch of the Nexus 9000," Fabbi said.