Cloud calling

PBX has come a long way since the days of a simple phone call over a copper line.
Matthew Burbidge
By Matthew Burbidge
Johannesburg, 07 Sept 2023
Natalie van der Merwe, Vox Telecom
Natalie van der Merwe, Vox Telecom

Jacques du Toit, CEO at Vox Telecom, has a companywide rule for his staff. If you’re on a call, he wants your camera on. His thinking is that it encourages engagement, and it seems to be bearing fruit as almost the whole company is still working remotely. The staff is also using Vox’s cloud-based PBX (private branch exchange) system for their video calls.

Natalie van der Merwe, head of telephony at the company, says while Covid accelerated the move to cloud, in truth, the move was well underway before the pandemic.

She says that in 2019, only 8% of sales were for on-prem PBX. Now, 100% are cloud-based.

The company has two cloud PBX products: a basic platform, called Verto, and an advanced one, from 3CX, which is its unified communications offering. This last option offers video calling, instant messaging, document-sharing and whiteboarding. It also pulls in SMSes, WhatsApp messaging, and there are social media plugins.

Van der Merwe says the success of a cloud-based PBX product depends on a number of factors. One is the stability of the data connection, which used to be on copper, but these lines are now being phased out for, among other reasons, theft. Another factor is how many users are using the same data link.

Beyond the phone call

“The better the quality of the data connection, the better the experience is going to be. If I’m running my voice over fibre, and I can separate the data from voice, I’m going to have a great experience. But If I’m using an internet connection, LTE, or ADSL, for example, I might have a worse experience on exactly the same platform.

“With the evolution of PBX, it went from on-prem to cloud and now we’re starting to look at what other layers we can include. PBX is not just about making and receiving a call anymore, it’s gone beyond that; it’s about how productive you can be, how to always be in contact and how people can see your status and know that you’re available,” says Van der Merwe.

The better the quality of te data connection the better the experience is going to be.

Natalie van der Merwe, Vox Telecom

She adds that customers also want to engage in ways other than a phone call. These include WhatsApp, Facebook, or a video call.

The final factor upon which successful PBX calling rests is the infrastructure itself. Here, things like network security and redundancy become important.

Van der Merwe says the user can access the PBX platform from anywhere in the word – at home in Joburg or on the beach in Mauritius.

The platform will use whatever data connection is available. If the caller is at home, it will use the FTTH link, or it could be over WiFi if they’re at a coffee shop. If they’re in the car, it will use the cellphone network, or a dedicated link at the office.

Beyond the phone call

Van der Merwe explains that once the call arrives at the PBX in the datacentre, it will be recognised because it’s from a registered extension. The call will then be routed to the intended person, either through a network operator, or, in the case of a colleague, through the exchange. In the latter case, the call will be free because both parties are on the same exchange.

What about using a PBX product from one of the hyperscalers?

Van der Merwe asks who is going to deliver the last-mile connectivity.

“Who’s going to install the phone at your site? And where will your data be stored? Some hyperscalers may not have a presence in this country, and that may be a problem. You also have to think about latency. If I’m accessing a platform that’s sitting in another country, what does that mean for my voice call? It has to travel out of South Africa, to the hyperscaler, and back again.”

She also asks who the customer will contact if there’s an outage.

“They won’t know if it’s a link issue, or a phone, or the PBX? There should be one throat to choke.”

Van der Merwe says moving to cloud is a global trend, and this isn’t just confined to PBX.

“Whether there’s a pandemic or not, it’s the way you need to go. Even if everyone is in the office, it doesn’t make sense to have a PBX on site. You’ve got a depreciating asset just sitting there. If you’re in the cloud, you have access to updates and upgrades all the time. It’s a no brainer.”


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