Load Balancer Appliance

Overview

A load balancer appliance is an application delivery controller that sits in front of a pool of servers and spreads incoming client traffic across them, so no single backend is overwhelmed and a failed server is simply taken out of rotation. Beyond distributing connections, it terminates TLS on behalf of the servers, inspects HTTP to route by URL or host, and tracks the health of every backend. The work that dominates its load is cryptography, so the platform pairs a multi-core SoC with a dedicated crypto engine and runs the whole thing on a 1U chassis with redundant power for an always-on edge role.

How it works

Client traffic enters on the Port Module. Copper ports pass through their Ethernet Magnetics for isolation and an Ethernet PHY that frames the packets, while the SFP+ cages take fiber or DAC uplinks to the upstream router. Packets cross into the Mainboard, where the Compute SoC Module runs the data plane: it terminates each connection, picks a backend from the configured pool, and rewrites and forwards the flow. Connection and session tables live in four ECC DDR4 ECC DIMM modules so millions of flows can be tracked at once.

When a connection is encrypted, the SoC hands the handshake and bulk cipher work to the SSL Offload Engine engine, which runs RSA/ECC key exchange and AES-GCM far faster than general-purpose cores, freeing them to do Layer-7 routing. Keys and the boot chain are anchored by the Trusted Platform Module. Configuration and logs persist on the NVMe SSD NVMe drive.

Thermals are handled by the Cooling Array, a front-to-back fan wall whose speed tracks die temperature, and two supplies in the Midplane share the load. Operators set the box up locally through the Front Panel and manage it out-of-band over the Management Port.