Commodity Switches Test Cisco's Mettle

There's been a fair amount of buzz over Arista Networks' recent filing to go public, fueled by the notion that this might be the company that has what it takes to kick sand in Cisco's face.

No doubt, Arista is the real thing. The vendor has an enviable customer list that includes Microsoft (accounting for more than 20 percent of Arista's 2013 revenues), Citigroup, Comcast, and Facebook. But what distinguishes Arista, as Matthew Palmer of SDNCentral noted, is delivering a huge switch based on merchant silicon with a network operating system built on open-source Linux.

Aside perhaps from the ubiquitous software-defined networking (SDN), the big buzzwords in the infrastructure business lately are "merchant silicon" and "open-source software," terms that are the very opposite of what's associated with traditional network vendors. There undoubtedly is a comfort factor in the traditional soup-to-nuts model, in which a single vendor provides custom silicon, the box itself, and a proprietary operating system with all the features. But such a solution also results in customer lock-in. Want a new feature? You'll have to wait until the vendor adds it to its software stack.

To view Arista as a David going up against Goliath (or Darth Vader?) would be to miss the wider guerilla war that is underway. There is a whole array of vendors looking to upend the traditional model. Moreover, Arista as an SDN vendor supports the notion that the network control plane (brains) should be separate from the forwarding plane (muscle). But it is the more fundamental threat from merchant silicon-based switches that Cisco's John Chambers referenced when he pooh-poohed Arista to editors at Barrons but voiced great concern about bare-metal switches.

The threat to Cisco is not just from SDN but also from a combination of bare-metal switches and network operating systems based on open-source software, specifically Linux. Bare-metal switches, based on ASICs from companies such as Broadcom, Intel, Marvell, and Mellanox, are available from brand-name companies like Dell as well as ODMs (original design manufacturers) such as Accton, Foxconn, and Quanta.

[Want to learn more about Cisco's approach to application-centric infrastructure? See Cisco Insieme ACI Goes Beyond SDN.]

In contrast to Arista's hardware, which is purpose built, bare-metal switches have opened the door to a new breed of independent network operating system vendors, such as Cumulus Networks and Pica8, both of which offer Linux-based network operating systems. That, in turn, allows customers to choose third-party, open-source, or commercial tools and applications.

These companies have generated a great deal of interest in enterprise IT even though both have targeted datacenter and cloud service providers. Cumulus has four ODM partners, including Dell, whose switches support Cumulus's Open Network Install Environment (which the vendor contributed to the Open Compute Project initiated by Facebook). Dell, interestingly, may be the first brand-name switch vendor to give customers the choice of network operating system.

Unlike Cumulus, which is in the business of licensing its network operating system, Pica8, while it licenses its software, also resells switches from its four ODM partners, ostensibly to ensure the quality of the switches. Pica8's announced customers include Baidu, NTT Communications, and Yahoo.

Any similarities between the two companies end there. While Pica8's network operating system supports OpenFlow, Cumulus does not, as network architect Jason Edelman noted in his blog. But he points out that might actually work to a customer's advantage because Cumulus and bare-metal vendor Big Switch Networks support the same switches, with the latter supporting OpenFlow in its switching software product.

Given the multidirectional threat to Cisco from SDN and bare-metal switches, it's understandable that the company appeared a bit schizophrenic in its Application Centric Infrastructure announcement, offering the new Nexus 9000 switches on both custom or merchant silicon. It's also selling the current Nexus 9000 with Cisco NX-OS, the operating system supported on Cisco 7000 and 6000 series switches, but will support a yet-to-be-released "enhanced" NX-OS built on Linux.

If that's not an endorsement, it sure seems like an acknowledgement that vendors like Arista, Cumulus, and Pica8 are onto something. The network equipment market is changing -- and fast.