What is a cloud PBX, and is it different from a virtual PBX?

A traditional PBX is a box in a cabinet. Line cards are fitted, cables run to the desks, and a technician is called for every new extension. If the office moves, the PBX moves with it.

A cloud PBX has no such box. The call travels over the internet using voice over IP, or VoIP. The phone can be a desk device, an app on a computer, a browser tab, or an app on a mobile. Adding a new employee means adding a line in the admin screen.

Call quality depends more on the connection than on the PBX itself. Phones sharing the office line with video meetings and file uploads sometimes hear broken audio. That is why the connection is measured before setup and the network is set to give voice priority.

• Extensions and groups.
• A greeting menu: one key for sales, another for support.
• Call routing and out-of-hours rules.
• Call queues and hold music.
• Call reports and optional call recording.

Some providers use the name virtual PBX for a number-based service set up on the operator side. Others use cloud PBX to stress that the PBX software is hosted in their own data centre. The name on an offer does not, on its own, tell you what the service is.

So look past the name to these questions. Where does the PBX run? Who handles updates and maintenance? In whose name is the number registered? If the answers match, the offers are the same service; if they differ, ask for the difference in writing before comparing prices. There is also the term IP PBX. An IP PBX is PBX software that carries calls over internet protocol, and it can run on a server in the office or in the cloud. Every cloud PBX is an IP PBX, but not every IP PBX is in the cloud.

Example scenario: Picture an estate agency with branches in Kadıköy and Maslak. Both branches share one extension plan, and a call to Kadıköy can be passed to an agent in Maslak. An agent working from home calls the client from the company number, not a personal mobile.

This is a change for the client too. The client knows the company number, not the agent's personal one. When an agent leaves, the client is not left wondering whom to call; the number stays with the company.

The second change is the record of the call. In a traditional PBX, the calling number stays in the device's memory. In a cloud PBX the call list sits in the admin screen and can be passed to other software. That handover is where the real value begins.

The third change is in administration. Opening an extension for a new employee, closing one for a leaver, and changing office hours are done from the admin screen without waiting for a technician. When a rule changes, the PBX changes the same day. Routing calls to an on-duty phone over a public holiday is a short job for one person.

The choice turns on the provider's BTK licence, number porting, the office connection, where call data is stored, and whether the PBX talks to your customer records. You can read about these criteria, setups per business type, the trial, and what to look for in the contract in the cloud PBX buying guide. In Corex360, calls are made from the browser through a WebRTC extension assigned to each staff member; the call history sits on the caller's customer card.

First, today's extension list is drawn up: who sits on which extension, which group takes which calls, where calls go out of hours. That list is the setup plan for the new PBX. In most offices it has never been written down; it grew out of settings a technician made over the years.

Next, the porting request is filed and a porting day is set. Until the port completes, the old line keeps working while the new PBX is tested with internal calls. The greeting recording, the out-of-hours rule, and the routing are tried before porting day. Finally, staff install the app on their phones or computers.

At a car parts dealer, the setting most often forgotten is the lunchtime routing. If the rule a technician set on the old PBX years ago is missing on the new one, calls at lunchtime reach nobody in the first week. That is why writing down the extension list is the foundation of the move.

In a dental clinic the missed-call list sits in the PBX panel. The receptionist checks it at noon, calls some back, forgets others. The list does not say which number belongs to a patient with an appointment and which is a new enquiry.

In Corex360 the PBX is a module of the core. Calls are made from the browser, and the history of incoming and outgoing calls sits on the caller's customer card. With the automatic information SMS switch on, when you call a customer, the number called receives an SMS introducing you. You can see how calls link to the same person as messages and email on bringing channels into one inbox.

We describe the screen and settings of the Corex360 PBX on the PBX module page.

Calls are made from the browser with a WebRTC extension assigned to the employee; the history of incoming and outgoing calls sits on the customer card of the calling number. If the automatic info SMS switch is on, the number you call receives an SMS introducing you. Because the call links to the same person as messages and email, whoever opens the card sees the latest conversation in one place, whichever channel it came through.

The PBX is a module on the same core as the CRM; it does not connect to a separate system. Each user is given a WebRTC extension, and the top of the window shows Connected or Not connected. Outgoing and missed calls are listed with date, time and duration. Call Center and Customers open as tabs in the same window. There is a NetGSM integration for the PBX and SMS.