HAPBX: The Scalable High-Availability Cloud PBX HAPBX revolutionizes business communication with a fully managed, high-availability cloud PBX platform designed for unmatched scalability and reliability. Unlike traditional providers that penalize growth with per-user fees, HAPBX utilizes a unique server-based pricing model. This allows businesses to deploy unlimited extensions and concurrent calls based simply on server capacity, significantly lowering Total Cost of Ownership. Built on a Global Cluster infrastructure, HAPBX guarantees near-zero downtime and enterprise-grade security. The platform adapts to specific business needs through tailored tiers: the Enterprise Cloud for robust daily operations, and the Call Center Cloud, which unlocks the complete Sonata Suite—including Dialer, Analytics, and Billing—for high-performance teams. For service providers, the Multi-Tenant Cloud offers secure management of multiple clients.