This is easily the most common complaint I get called out for. The line is fine, a speed test next to the router proves it, but the office feels slow. Almost always, the fibre isn't the problem. Here's what usually is.
1. One router trying to cover a whole building
Your ISP supplies a router designed for a two-bedroom flat with a handful of devices. You've put it in a corner office, behind a filing cabinet, in a building with brick internal walls, and asked it to serve twenty-five devices. It cannot do that, and no amount of rebooting will change it.
The fix: proper access points, positioned where people actually work, each connected back by network cable. Two or three well-placed access points will comprehensively beat one expensive router.
2. Wi-Fi extenders daisy-chained across the office
Extenders are the most tempting bad solution in networking. Each one roughly halves your available bandwidth, because it has to receive and retransmit on the same radio. Chain three together and your 200 Mbps line arrives at the far desk as a trickle with high latency, which is precisely why calls break up there.
The fix: cable to access points instead. Cabling is unglamorous and it's the single highest-value thing most offices can do to their network.
3. Everyone on 2.4 GHz
The 2.4 GHz band travels further through walls but is slower and heavily congested, every neighbouring business, microwave, wireless mouse and Bluetooth device competes in it. In a Centurion or Pretoria office park you might have thirty other networks in range on the same few channels.
The fix: get devices onto 5 GHz where they can be, with channels chosen deliberately rather than left on auto. This costs nothing but configuration time.
4. One device saturating the line
A single machine running cloud backup mid-morning, downloading a Windows feature update, or syncing a huge shared folder can consume most of your upload capacity. Upload matters more than people expect, because video calls, sending files and VPN traffic all depend on it.
The fix: traffic shaping or QoS on a managed router, so video calls get priority over background sync, and backups get scheduled for the night.
5. Guest devices on the business network
Visitors, staff phones and the smart TV in reception all sitting on the same network as your work machines. Beyond the bandwidth, this is a genuine security problem. One infected phone has a clear path to your file storage and accounting PC.
The fix: a separate guest network with VLAN segmentation and a bandwidth cap. Again, configuration rather than hardware.
6. It isn't the Wi-Fi at all
Sometimes the wireless is fine and the actual fault is upstream: a failing ISP line, packet loss on the fibre, an overloaded switch, a faulty cable, or DNS resolving slowly. This is why I measure before recommending anything. Replacing hardware hopefully is how businesses spend money and stay slow.
The fix: proper diagnosis. Latency, packet loss and throughput tested at multiple points to identify where performance actually degrades.
What good looks like
A functional small-business network has a decent router or firewall at the fibre handover, a managed switch, two or more access points on cable positioned by coverage need, guest traffic segmented away from business traffic, no default admin passwords, and a written diagram so the next problem takes minutes to find rather than hours.
None of that is exotic or expensive at office scale. It's just rarely done, because the ISP router works well enough on day one and nobody revisits it as the business grows.
If this sounds like your office, network setup and Wi-Fi is what I'd look at, and it starts with a site visit rather than a quote over the phone.
Let’s sort out your IT
Tell me what you need and I’ll come back to you within 2 to 4 hours during business hours. Usually with a fixed quote rather than a sales call. You deal directly with me.