Arista Networks

Corporate history

Andy Bechtolsheim co-founded Sun Microsystems in 1982 and was its chief hardware designer. In 1995, David Cheriton co-founded Granite Systems with Bechtolsheim, a company that developed Gigabit Ethernet products, which was acquired by Cisco Systems in 1996. In 2001, Cheriton and Bechtolsheim founded another start up, Kealia, which was acquired by Sun in 2004. From 1996 to 2003, Bechtolsheim and Cheriton occupied executive positions at Cisco, leading the development of the Catalyst product line, along with Kenneth Duda who had been Granite Systems' first employee.

In 2004, the three then went on to found Arastra (later renamed Arista). Bechtolsheim and Cheriton were able to fund the company themselves. In May 2008, Jayshree Ullal left Cisco after 15 years at the company, and was appointed CEO of Arista in October 2008.

In June 2014, Arista Networks had its initial public offering on the New York Stock Exchange under the symbol ANET.

In December 2014, Cisco filed two lawsuits against Arista alleging extensive intellectual property infringement. As a result of the first lawsuit, the United States International Trade Commission issued limited exclusion and cease-and-desist orders concerning two of the features patented by Cisco and upheld an import ban on infringing products. The decision is being appealed to the United States Court of Appeals for the Federal Circuit.

Extensible Operating System

EOS is Arista's network operating system, and comes as a single image that runs across all Arista devices or in a virtual machine. EOS runs on an unmodified Linux kernel under a Fedora-based userland. There are more than 100 independent regular processes, called agents, responsible for different aspects and features of the switch, including drivers that manage the switching ASICs, the CLI, SNMP, Spanning Tree Protocol, and various routing protocols. All the state of the switch and its various protocols is centralized in another process, called Sysdb. Separating processing (carried by the agents) from the state (in Sysdb) gives EOS two important properties. The first is software fault containment, which means that if a software fault occurs, the damage is limited to a single agent. The second is stateful restarts, since the state is stored in Sysdb, when an agent restarts it picks up where it left off. Since agents are independent processes, they can also be upgraded while the switch is running (a feature called ISSU – In-Service Software Upgrade).

The fact that EOS runs on Linux allows the usage of common Linux tools on the switch itself, such as tcpdump or usual configuration management systems. EOS provides extensive APIs to communicate with and control all aspects of the switch. To showcase EOS' extensibility, Arista developed a module dubbed CloudVision that extends the CLI to use XMPP as a shared message bus for managing and configuring switches. This was implemented simply by integrating an existing open-source XMPP Python library with the CLI.

Programmability

In addition to all the standard programming and scripting capabilities traditionally available in a Linux environment, EOS can be programmed using different mechanisms:

Ethernet switches

Arista's product line can be separated in eight families:

1. 7500E series: Modular chassis with a VOQ fabric supporting up to 4 or 8 store and forward line cards delivering line-rate non-blocking 10GbE, 40GbE, and 100GbE performance in a 30Tbit/s fabric supporting a maximum of 1152 10GbE ports with 144GB of packet buffer. Each 100GbE ports can also operate as 3x40G or 12x10G ports, thus effectively providing 120Gb of line-rate capacity per port.
2. 7300 series: Modular chassis with 4, 8, or 16 line cards with 2.56Tbit/s of capacity per line card, for a fabric totaling up to 40Tbit/s of capacity for up to 2048 10GbE ports. Unlike the 7500 series, 10GBASE-T is available on 7300 series line cards.
3. 7200 series: 2U low-latency high-density line-rate 40GbE switches, with 5.12Tbit/s of forwarding capacity.
4. 7100 series: 1U ultra-low latency cut-through line-rate 10Gb switches. The 7124SX has a sub 500ns port-to-port latency, regardless of the frame size.
5. The 7124FX, dubbed the "Application Switch," includes an Altera FPGA capable of processing 8 x 10Gbit/s, which made possible "cut-through high-frequency trading," in which algorithmically generated trades were incurring an additional latency of only 176ns.
6. 7150 series: 1U ultra-low latency cut-through line-rate 10Gb switches. Port-to-port latency is sub-380ns, regardless of the frame size. Unlike the 7100 series, the switch silicon can be re-programmed to add new features that work at wire-speed, such as VXLAN or NAT/PAT.
7. 7050 series: 1U low-latency cut-through line-rate 10Gb and 40Gb switches. This product line offers a higher port density than the 7100 series, with a minimum of 52 x 10GbE ports, at the expense of slightly increased latency (1.2µs or less).
8. 7048 series: 1U store and forward line-rate 1Gb top-of-rack switch, with 4x10Gb uplinks. These switches use a Deep Buffer architecture, with 768MB of packet memory.
9. 7010 series: 1U low power (52W) line-rate 1Gb top-of-rack switch, with 4x10Gb uplinks.

The low-latency of Arista switches has made the platform prevalent in high-frequency trading environments, such as the Chicago Board Options Exchange (largest U.S. options exchange), Lehman Brothers or RBC Capital Markets. As of October 2009, one third of its customers were big Wall Street firms.

Arista's devices are multilayer switches, which support a range of layer 3 protocols, including IGMP, VRRP, RIP, BGP, OSPF, IS-IS, as well as OpenFlow. The switches are also capable of layer 3 or layer 4 ECMP, and applying per-port L3/L4 ACLs entirely in hardware.

All of Arista's switches are built using merchant silicon instead of custom switching ASICs. This strategy enables Arista to leverage latest advances in processor manufacturing technology at a lower price point, due to the prohibitive costs associated with the development and production of custom chips. Other major competitors such as Cisco and Juniper have also started following the same strategy, which led to multiple competing products built on top of the same chips. For instance Broadcom's Trident chip is used in some Cisco Nexus switches, Juniper QFX switches, Force10, IBM and HP switches. The integration of the chips with the rest of the system (including integration with the MAC, PHY, and device drivers on the control plane) and software are what differentiate the competing products.

In November 2013, Arista Networks introduced the Spline network, combining leaf and spine architectures into a single-tier network, which aims to cut operational costs.

Major competitors

1. Brocade Communications Systems
2. Cisco Systems
3. Extreme Networks
4. Juniper Networks