# High Availability and Scalability On-Premise

A modern unified communications system is much more complicated than the phone system of a lot of years ago — most likely, it’s now running on commodity PC, Server, and private cloud platform infrastructure rather than a custom-built hardware chassis.  It’s now connected to the Internet, and probably sends calls across the network as well, instead of having dedicated analog or digital lines for each extension and for each connection to the outside world.

When installing a modern unified communications system, the topic of resiliency is often of high importance.  Customers expect their unified communications system to be resilient, despite the ever-increasing complexity. 

With PortSIP PBX solutions, PortSIP is glad to give the HA function, which allows it to take over in the event that the server fails. Modern unified communications systems are significantly more complex than traditional phone systems of the past. Rather than relying on proprietary, purpose-built hardware, today’s solutions typically run on **commodity PCs, standard servers, and private or public cloud infrastructures**. They are fully IP-based, connected to the Internet, and transport voice and video traffic over data networks, instead of using dedicated analog or digital lines for each extension or external connection.

As a result of this increased complexity and dependency on IP infrastructure, **system resiliency has become a critical design requirement**. Organizations now expect their unified communications platform to remain available at all times, even in the event of hardware failures, network disruptions, or service outages.

With **PortSIP PBX**, high availability (HA) is built into the solution by design. The HA functionality enables automatic failover, allowing the system to seamlessly take over operations when a server failure occurs. This ensures continuous service availability, minimizes downtime, and meets the reliability expectations of modern enterprise and service-provider deployments.


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