In a white paper describing how VESPA works, Arista wrote:
The first component of VESPA involves Arista access points creating VXLAN tunnels to Arista switches serving as WLAN Gateways…. Second, as device packets arrive via the AP, it dynamically creates an Ethernet Segment Identifier (Type 6 ESI) based on the AP’s VTEP IP address. These dynamically created tunnels can scale to 30K ESI’s spread across paired switches in the cluster which provide active/active load sharing (performance+HA) to the APs. Third, the gateway switches use Type 2 EVPN NLRI (Network Layer Reachability Information) to learn and exchange end point MAC addresses across the cluster. … With this architecture, adding more EVPN WLAN gateways scales both AP and user connections, to tens of thousands of end points.
To manage the forwarding information for hundreds of thousands of clients (e.g: FIB next hop and rewrite) would prove very complex and expensive if using conventional networking solutions. Arista’s innovation is to distribute this function across the WiFi access points with a unique MAC Rewrite Offload feature (MRO). With MRO, the access point is responsible for servicing mobile client ARP requests (using its own mac address), building a localized MAC-IP binding table, and forwarding client IP addresses to the WLAN gateways with the APs MAC address. The WLAN Gateways therefore only learns one (MAC) address for all the clients associated with the AP. This improves the gateway’s scaling from 10X to 100X, allowing these cost effective gateways to support hundreds of thousands of clients attached to the APs.
AVA system gets a boost
In addition to the new wireless technology, Arista is also bolstering the capabilities of its natural-language, generative AI-based Autonomous Virtual Assist (AVA) system for delivering network insights and AIOps.
AVA is aimed at providing an intelligent assistant that’s not there to replace people but rather help them do their job better, said Jeff Raymond, vice president, EOS product management and services at Arista.
“AVA is a chat interface into our data lake. But instead of just providing you easy search responses, like, ‘tell me where this user is sitting,’ the chat interface uses an LLM on the back end to rationalize and reason with the telemetry information and get the end user to something that’s much more precise in terms of troubleshooting, in terms of being able to just find an issue more quickly, or be able to even prevent an issue,” Raymond said. The LLM component is new and has been in product preview until now.
With the AVA insights component, “we’re looking at being able to use our best practices, our technical expertise, but codified,” he said. Then we’re able “to run those as agents, so that we can look for problems in a network and be able to proactively alert a user before they happen.”
Arista has also added the ability to handle multi-domain event correlation across wired, wireless, data center, and security to isolate a root cause of a problem. AVA can then perform continuous monitoring and automated root cause analysis for proactive issue identification, Raymond said.
