
Arista Networks 7500 Series

Overview
The Arista 7500 Series modular switch sets a new standard for performance, density, reliability, and power efficiency for data center switches. In a compact 7RU (4-slot) or 11RU (8-slot) chassis, the Arista 7500 Series offers up to 10 Terabits of fabric capacity, 384 wirespeed 10 GbE ports and 5.76 BPPS of L2/3 throughput. The Arista 7500 offers a comprehensive feature set, as well as future support for the 40GbE and 100GbE standards. With front-to-rear airflow, redundant and hot swappable supervisor, power, fabric and cooling modules, the 7500 is energy efficient with typical power consumption of 10 watts per port for a fully loaded chassis. All of these attributes make the Arista 7500 an ideal platform for building low latency, scalable, data center networks.
Arista Networks Extensible Operating System
All Arista products including the 7500 series switches run Arista EOS software. The same binary image supports all Arista products, making it easy for network administrators to standardize the operating system across all switches in the data center. With the
addition of Arista 7500, EOS has been extended to support redundant supervisor modules with stateful switchover without the loss of data plane forwarding.
Arista EOS is a modular switch operating system with a unique state sharing architecture that cleanly separates switch state from protocol processing and application logic. Built on top of a standard Linux kernel, all EOS processes run in their own protected memory space and exchange state through a memory based database. This multi-process state sharing architecture provides the foundation for in-service-software updates and self-healing resiliency. Arista EOS automates the networking infrastructure natively with VMware vSphere via VM Tracer to provide VM discovery, auto-VLAN provisioning, and unprecedented visibility into the virtual computing environment.
Scaling Data Centre Performance
The Arista 7500 enables dramatically faster and simpler network designs for large-scale data centers. When used in conjunction with Arista 7048 or 7100 leaf switches and Arista’s Multi-Chassis Link Aggregation (MLAG) technology, a pair of 7508 Switches can support 9200 Servers with a leaf/spine active/active L2 network topology. With four Arista 7508 switches at Layer 3, more than 18,000 Servers can be connected with a non-blocking, low-latency, two-stage network that provides predictable end-to-end application performance.
Deterministic Network Performance
The Arista 7500 uses a deep buffer virtual output queue (VOQ) architecture that eliminates head-of-line (HOL) blocking and virtually eliminates packet drops even in the most congested network scenarios. An advanced traffic scheduler fairly allocates bandwidth between all virtual output queues while accurately following queue disciplines including weighted fair queueing, fixed priority, or hybrid schemes including 802.1Qaz ETS. As a result, the Arista 7500 can handle the most demanding data center requirements with ease, including mixed traffic loads of real-time, multicast, and storage traffic.
Designed for High Availability
The Arista 7500 is designed specifically for high-availability requirements. The hardware supports hot-swappable redundant power, cooling, fabric, supervisors, and linecards. The fabric is N+1 redundant with graceful degradation. The Arista EOS software supports stateful failover between the redundant supervisors as well as self healing and live patching through in-service- software updates.

The Arista 7500 delivers unmatched throughput, and leverages the unique combination of performance, density, and deep buffering to build larger flatter networks optimized for data centers, virtualization, and cloud computing.
Wirespeed Throughput
The Arista 7500 can forward on all ports at Layer-2 and Layer-3 at wirespeed while simultaneously switching and routing unicast and multicast traffic. There are eight linecard modules in the system and each linecard provides 720 Mpps of throughput. Aggregated together, the system can forward 5.76Bpps. The linecard modules are always non-blocking. The ports forward at full line rate in all scenarios, at all packet sizes – small and large.
- Port-pairs: With up to 192 pairs, all ports can send to each other without affecting performance.
- Full-Mesh: Performance is not impacted based on full-mesh traffic patterns in the Arista 7500. Even with a full mesh, any-to-any workload the Arista 7500 forwards without dropping any frames.
Low Latency
The low-latency virtual output queue fabric (VOQ) and an advanced traffic scheduler results in minimal delay in forwarding. All packets are received and stored on the ingress packet processor, which is equipped with very deep buffers. In parallel, while storing the packets, a forwarding decision is made by the scheduler as quickly as possible and the packet is divided and sent across the fabric to the egress port(s). The packet is re-assembled and transmitted out in most cases without any delays. This results in a very low latency – under 5 microseconds on average, for standard Ethernet frame sizes.
10 Terabit Lossless Fabric / Deep Buffer Congestion Management
With 384 MB of packet buffer for every eight ports, data gets queued when the egress interfaces are experiencing wide fan-in of traffic, or when supporting 10Gb to 1Gb transitions. The deep buffers ensure that congestion is absorbed and the egress interfaces are always working at their most efficient. This minimizes retransmission and results in much better performance at the application level. This ability to handle congestion, along with hardware support for Priority Flow Control (PFC), makes the system well suited for all applications that require a lossless fabric such as IP Storage, NAS, and video origination services.
The Arista 7500 switch comes with 6 fabric modules. Each fabric provides 1.66 Tbps of switching capacity. Only 5 fabrics are needed at any given time to provide full non-blocking performance.

Arista Networks 7500 Series Linecard Architecture
Arista commissioned the European Advanced Network Test Center to validate the performance of the Arista 7500 Series. A complete report showing the performance and results of this in-depth testing can be accessed here.















