Arista's Programmable Switches Should Scare Cisco


By: R. Scott Raynovich

Arista Networks (ANET), which has been steadily gaining data-center switching market share from market-leader Cisco (CSCO), made another major leap forward this week by announcing a new series of leaf and spine switching products with programmable chips.

The move to programmable hardware is yet another threat to Cisco, which already finds itself a target for the open networking movement, which is "disaggregating" switching hardware and software to help lower costs.

The Arista 7170 Series is based on the programmable Tofino ASIC from startup Barefoot Networks. The switches scale up to 64 100 Gigabit/s ports (100G). Arista says that by using the Tofino chip, the 7170 series will be more flexible in adopting important security features and network-address translation (NAT), which require high-performance processing in data-center environments.

All of Barefoot's Tofino chips can be programmed with the P4 language, which describes how packets should be forwarded by switches, routers, and network interface cards (NICs) -- the so-called "data plane." Many networking experts consider programmable switches and P4 to be the next phase of software-defined networking (SDN), wherein more intelligence can be programmed directly into the hardware infrastructure, or "underlay" as it's known in the business. At the same time, the use of programmable switches means that they can be re-programmed when they are deployed for new applications, rather than hard-coded for a specific task. This has broad applications for switches that can rapidly adopt specialized packet-processing features such as security, which have often been handled by separate hardware and software appliances.

Barefoot is a pioneer in building chips compatible with P4 language. P4 was created by a consortium of cloud researchers including those at Microsoft, Google, and Stanford University, and it has been championed by one of Barefoot's founders and its Chief Scientist, Nick McKeown, a software-defined networking (SDN) visionary who helped found startup Nicira (purchased by VMware for more than $1B in 2012). Many see P4 as a more sophisticated successor to the OpenFlow protocol, a key technology which helped launch SDN but some consider to have more limited applications.

"With Tofino, Barefoot has proven that programmability can be delivered without compromise on performance and I believe that future switch chips will be fully programmable – there is no reason not to," said McKeown in the Arista press release. "It allows protocols to be lifted up and out of hardware into software. Arista's first Tofino based platforms do exactly that, using P4 to deliver customized profiles to their customers. Programmable switches take differentiation in the market to a whole new level."

What's interesting is that Arista has created an entirely new switch family based on programmable chips, while the majority of its switches run on merchant silicon primarily manufactured by Broadcom (AVGO). This is a big shift and it should make legacy switching and routing providers, such as Cisco and Juniper Networks, very nervous. Both Cisco and Juniper were slow to migrate away from the model of making their own Application Specific Integrated Circuits (ASICs) to Broadcom's merchant silicon, a trend that Arista took advantage of. Now Arista is moving on to a new level of innovation in switching, threatening to leapfrog the traditional hardware switching manufacturers yet again.