Operating System and Hardware Requirements for VICIdial

Before you install anything, it pays to pick the right operating system and size the box correctly. A dialer is harder on a server than a normal web app, because it is moving live audio in real time. Get the foundation right and the rest of the install behaves; get it wrong and you will fight audio quality forever.

Supported operating systems

VICIdial runs on Linux, and a handful of distributions are the well-trodden choices. The packaged ViciBox image is built on openSUSE. From-scratch builds are common on Debian and Ubuntu. Whichever you pick, stick to a release that the VICIdial code and your chosen Asterisk version are known to work with, rather than the newest possible release. A bleeding-edge OS often renames packages or ships library versions Asterisk has not been built against yet.

Why audio drives the sizing

Each live call is a Channel in Asterisk, and every channel uses CPU and memory to handle its audio. The number you really care about is Concurrent calls: how many calls are up at the same moment, which is always higher than your agent count because a predictive dialer rings several numbers per available agent. Size for the peak, not the average.

flowchart TD
  A[Agent count] --> B[Lines per agent]
  B --> C[Peak concurrent calls]
  C --> D[CPU cores needed]
  C --> E[RAM needed]
  C --> F[Network capacity]
  D --> G[Server size]
  E --> G
  F --> G

CPU, RAM, and disk guidance

As a rough shape: a small single-server setup for a handful of agents runs comfortably on a few CPU cores and a few gigabytes of RAM. As you climb toward dozens of agents and the higher concurrent-call counts that brings, you want more cores and more memory, and at some point you split telephony, web, and database onto separate boxes. Disk needs grow mainly from call recordings, which pile up fast; plan storage around how long you must keep them.

• CPU: enough cores to carry your peak concurrent calls with headroom, since transcoding and predictive math both cost cycles.
• RAM: room for the database working set, Asterisk channels, and the background Perl workers all at once.
• Disk: sized for recordings and database growth over your retention window, on fast storage.

Why a dedicated box matters

Real-time audio does not tolerate noisy neighbors. If your dialer shares a host with other busy workloads, calls develop choppy or one-way audio under load. This is the catch with cheap shared hosting. A dedicated box, or a VPS with guaranteed resources rather than oversubscribed ones, keeps audio clean. When you connect a carrier through a Server trunk, that link also expects steady, low-latency networking that a contended host cannot promise.

It is tempting to start small and grow into a box, but a dialer punishes undersizing in a way that is easy to feel and hard to hide: dropped calls, lag on the agent screen, and reports that lag behind reality. Buy a little headroom over your expected peak so a busy hour does not tip the server over. It is cheaper than the lost calls and the rebuild you would otherwise face a month in.

For how these requirements feed into the rest of the setup, read our complete VICIdial install guide. If you are weighing the true cost of running your own box, the hidden cost of self-hosted VICIdial is worth a read.

If you would rather not size and source hardware yourself, VICIfast runs each dialer on a dedicated server and provisions it in under 40 seconds. See VICIfast pricing.