VoIP for business in South Africa: internet phones explained
Last reviewed: September 2026
VoIP (voice over internet protocol) carries phone calls as data over an internet or network connection instead of a copper line. Internet phones for business use it to give every person an extension at a desk, at home or on a mobile. Arke Technologies designs and supports business VoIP across South Africa.
VoIP for business in South Africa: internet phones explained
Last reviewed: September 2026, 14 min read
VoIP (voice over internet protocol) carries phone calls as data over an internet or network connection instead of a copper line. Internet phones for business use it to give every person an extension at a desk, at home or on a mobile. Arke Technologies designs and supports business VoIP across South Africa.
Last reviewed: September 2026, 14 min read
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What is VoIP? Definition and meaning
The VoIP definition in one sentence: voice over internet protocol (VoIP) is a way of making telephone calls in which your voice travels as data across an IP network, the same kind of network that carries email and web pages, instead of over a dedicated copper circuit. It is also written voice over IP (VoIP), IP telephony or internet telephony, and the meaning is the same.
To define VoIP by what it replaces: a traditional landline reserves a circuit for the whole call, while VoIP cuts the conversation into small packets, sends them across whatever network is available and reassembles them at the other end quickly enough that neither caller notices.
You have probably used VoIP already: a Microsoft Teams call, or a call over Wi-Fi from a phone app, is a VoIP call. In an organisation, VoIP means the whole phone system (extensions, reception, call queues, voicemail and outside numbers) runs over the data network, and internet phones for business can sit on a desk, in a pocket or on a laptop. This guide is part of our insights for IT and operations leaders.
Internet phones for business: the devices
What is a VoIP phone, and what counts as a VoIP device? Any device that registers to the phone system and carries calls as data:
Desk IP phones. A VoIP telephone with a screen and programmable keys, plugged into the network and powered by it through power over Ethernet (PoE). It suits reception, finance and anyone on the phone all day.- Cordless DECT handsets. Base stations on the network, with handsets that roam around a warehouse, clinic, school office or factory floor.
- Softphones. A VoIP app on a laptop or mobile phone that carries the same extension, so a call to the office number rings wherever the person is working.
- Conference phones and meeting-room systems. For boardrooms and meeting rooms, including Microsoft Teams Rooms.
- Analogue telephone adapters. For devices that still expect a phone line: lift emergency phones, gate intercoms, alarm diallers and the occasional fax machine.
- Headsets. For contact-centre agents and heavy phone users, wired or wireless.
Desk phones, cordless handsets, headsets and PoE switches are quoted in rand, VAT included, by Server Hub (opens serverhub.co.za), our hardware division.
What your network needs for clear calls
- Capacity for your busiest hour. Each call is a steady stream in both directions, so size the link for the most calls you carry at once, not the daily average.
- Quality of service. Voice traffic marked and prioritised on switches, Wi-Fi and the internet router, so a large download cannot crowd out a call.
- A voice network segment. A separate virtual LAN for phones keeps voice traffic predictable and easier to secure.
- PoE capacity and backup power. The switch that powers desk phones needs enough PoE budget and a UPS; so do the router and the fibre terminal, or load-shedding silences the phones.
- A second connection. An LTE or 5G link on a different network, or calls diverted to mobile apps, keeps the organisation reachable when the main link fails. Across several sites, SD-WAN steers calls down the healthiest link automatically.
- Wi-Fi designed for roaming. Softphones and Wi-Fi handsets need coverage without gaps, especially in warehouses and schools; see business Wi-Fi.
- Sensible router settings. Some routers' SIP helper features (SIP ALG) rewrite call signalling and cause one-way audio or dropped calls, so they are usually switched off for hosted VoIP.
The line itself matters most. Our guide to business fibre vs home fibre sets out what to ask of it.
What VoIP costs to run
Last reviewed: September 2026
- Licences or seats, per user or extension per month on hosted platforms. Teams Phone adds a licence per user on most Microsoft 365 plans.
- Numbers, with a monthly charge per number on many services.
- Call charges, per minute or per second, or in bundles. Calls to mobiles and international numbers usually cost more than calls to landlines.
- Channels, the number of calls a SIP trunk can carry at the same time.
- Devices, desk phones, cordless handsets, headsets and adapters, or softphones with no hardware cost.
- Network work, such as PoE switches, Wi-Fi, cabling and backup power where a site is not ready.
- Setup and migration: design, number porting, configuration and training, usually as a once-off project.
- Support: administration and moves, adds and changes, in-house or under a managed service.
We do not publish call rates or setup prices. We quote in writing after a call-flow audit, with once-off and monthly costs shown separately, so you can compare them with your current phone bill over the contract term.
Risks, and how to prevent them
- Toll fraud. Criminals who break into a PBX or steal SIP credentials run up international and premium-rate calls on your account. Strong unique credentials, multi-factor authentication for administrators, dialling restrictions by country and time, spend limits and alerts on unusual call patterns prevent it.
- Caller ID spoofing. A VoIP caller can present any number as caller ID, so staff should verify requests for payments, passwords or banking changes by calling back on a number they already know. Your own system should present only numbers you hold.
- Poor call quality. It is almost always a network problem. Test the network before migrating, and monitor call quality afterwards.
- Outages. Power and internet failures stop calls unless equipment is on backup power and calls can divert to mobile apps.
- Porting delays. A mismatch in account details can stall a number port, so plan the cut-over and test every number.
- Emergency calls. Confirm how the provider routes emergency calls and which address it records for each number, especially for staff who work from home.
- Call recordings under POPIA and RICA. Recordings are personal information: tell callers, set retention periods and restrict access; see POPIA compliance. RICA also governs recording: a business may record calls on its own system for business purposes if it has made reasonable efforts to tell users in advance, or has their consent.
- Lock-in. Keep administrator access, number records and call-flow documentation in your organisation's name.
Governance, compliance and procurement
- Governance. Written change control for call flows and numbering, escalation paths, and a monthly service review and report.
- Compliance. Call recordings and voicemail are handled under POPIA and RICA, with retention, access controls and caller notices your Information Officer can account for. Public bodies get documentation that suits PFMA and MFMA audits and King IV Principle 12 reporting.
- Procurement. Arke Technologies (Pty) Ltd is a Level 1 B-BBEE contributor (sworn affidavit available on request), giving buyers 135% procurement recognition. Company documents, our CSD supplier number and SARS tax compliance status are available on request. You can buy on a written proposal and SLA against your purchase order, or through a tender, for which we complete the standard bidding documents (SBD forms).
- Continuity. Administrator credentials, number records, call-flow designs and recordings stay yours, documented so that another team could run them.