Shopping for fibre means wading through acronyms (FNO, ONT, CGNAT, FUP) that providers rarely stop to explain. None of it is complicated once it’s in plain language. Here’s a no-nonsense glossary of the terms you’ll meet on any South African deal, grouped so you can find what you need and get back to choosing a package.
The players
| Term | What it means |
|---|---|
| FNO (Fibre Network Operator) | The company that owns the physical fibre cable in the ground and the box on your wall, such as Vumatel, Openserve, Frogfoot, Octotel or MetroFibre. It decides where fibre is built and what speeds the line can carry. |
| ISP (Internet Service Provider) | The company you pay each month for internet, such as Afrihost, Webafrica, Vox or MWeb. It sells you a package that runs over an FNO’s line. |
| Open access | The SA model where one FNO line can be used by many competing ISPs. It’s why you can switch ISP without a new installation. |
| Reseller | A provider that sells access over another network rather than owning infrastructure. Many “brands” are resellers on the big FNOs. |
The one distinction that matters most: the FNO controls coverage and maximum speed; the ISP controls price and service. Understanding this unlocks better deals. See who is my fibre ISP and SA fibre networks compared.
Connection types
| Term | What it means |
|---|---|
| Fibre (FTTH) | Fibre To The Home: a glass cable run all the way to your house. The fastest, most stable mainstream option. |
| FTTB | Fibre To The Building: fibre to a block of flats or office, often shared from there to individual units. |
| LTE / 4G | Mobile broadband over cellular towers. No trenching needed, so it’s a good bridge while you wait for fibre. |
| 5G | The latest mobile standard, much faster than LTE where there’s coverage, and a real fibre alternative in some areas. See fibre vs 5G. |
| Fixed wireless | A home internet service delivered over LTE/5G to a fixed router at your address, usually month-to-month. |
| ADSL | The old copper-line broadband, now largely retired in favour of fibre. |
| LEO satellite (e.g. Starlink) | Internet beamed from low-orbit satellites, useful in rural areas beyond fibre and mobile reach. |
Speed & performance
| Term | What it means |
|---|---|
| Mbps | Megabits per second, the standard speed unit. A “100 Mbps” line moves up to 100 megabits each second. |
| Mbps vs MB/s | Bits versus bytes. There are 8 bits in a byte, so a 100 Mbps line downloads at roughly 12.5 MB/s at best. |
| Download / upload | Download is data coming to you (streaming, browsing). Upload is data leaving you (video calls, backups, posting). |
| Symmetrical | Equal download and upload speeds (e.g. 100/100). Common on fibre and great for video calls and working from home. |
| Asymmetrical | Faster download than upload (e.g. 100/50). Typical on many entry packages and most wireless. |
| Latency / ping | The delay before data starts moving, in milliseconds. Lower is better; it’s what makes gaming and calls feel responsive. |
| Jitter | Variation in latency. High jitter causes stuttery calls and lag spikes even on a “fast” line. |
| Bandwidth | The maximum capacity of your line. Think of it as the width of the pipe. |
| Contention ratio | How many users share underlying capacity. Higher contention can mean slowdowns at peak times. |
A common surprise: a lower-numbered but stable line often feels faster than a high-numbered one that wobbles, because latency and jitter shape the everyday experience as much as raw Mbps. We unpack real-world speeds in our speed guide.
Data & fair-use terms
| Term | What it means |
|---|---|
| Uncapped | No data limit, so use as much as you like. Standard on most home fibre. See uncapped fibre explained. |
| Capped | A fixed data allowance per month (more common on LTE/5G); once used up, you top up or slow down. |
| Shaped | Certain traffic types (e.g. downloads) are given lower priority, so they slow when the network is busy. |
| Unshaped | All traffic treated equally, generally a better experience. Often paired with “unthrottled”. |
| Throttling | Deliberately slowing your speed, usually after heavy use or on a fair-use trigger. |
| FUP (Fair Use Policy) | The fine print on “uncapped” plans: extreme, sustained heavy use can be slowed to protect other users. Most households never hit it. |
Hardware in your home
| Term | What it means |
|---|---|
| ONT | Optical Network Terminal, the FNO’s box where the fibre cable terminates on your wall. It usually carries the network’s branding. |
| Router / CPE | The device (often supplied by your ISP) that creates your Wi-Fi and shares the connection to your devices. CPE means Customer Premises Equipment. |
| Drop cable | The fibre cable running from the street into your home. Damage to it (e.g. garden work) is a common fault. |
| Splice | A join in the fibre cable, done by a technician with specialised kit. |
| LOS light | A “Loss of Signal” indicator on the ONT, usually red. It typically means a physical break in the line, not a router glitch. |
| PPPoE | A login method some ISPs use; you enter a username and password into the router to authenticate the connection. |
| Mesh Wi-Fi | Multiple linked access points that blanket a larger home in signal, instead of one router struggling to reach every room. |
| Dual-band / Wi-Fi 6 | Modern Wi-Fi standards. Dual-band uses 2.4 GHz (range) and 5 GHz (speed); Wi-Fi 6 improves performance in busy homes. |
Slow Wi-Fi isn’t always a slow line. Often the fibre is fine and the bottleneck is router placement or an old router. Our guide to fixing slow Wi-Fi covers the quick wins before you blame your ISP.
Billing & contract terms
| Term | What it means |
|---|---|
| Month-to-month | No fixed term; cancel with short notice (usually a calendar month). More flexible, sometimes slightly pricier. See month-to-month vs contract. |
| Contract (fixed term) | A 12 or 24-month commitment, often with a free router or discounted rate; early cancellation usually carries a penalty. |
| Pro-rata | A part-month charge. For example, when you start or change a service mid-month you pay only for the days used. |
| Activation / installation fee | A once-off charge to set up the service. Often waived on promotions or contract sign-ups. |
| Static vs dynamic IP | A static IP stays the same (useful for remote access or servers, sometimes an add-on); a dynamic IP changes periodically and is the default. |
| CGNAT | Carrier-Grade NAT, where many users share one public IP. Fine for normal use, but it can complicate gaming hosting and remote access; some ISPs offer a way around it. |
| Debit order | The recurring monthly payment most ISPs bill by. Tracing yours is a quick way to confirm which ISP you’re actually with. |
You don’t need to be technical to choose well. You just need the jargon decoded. Once the words make sense, the right deal is obvious.
That’s the vocabulary that covers almost every fibre deal in South Africa. With the terms decoded, the next step is seeing what’s actually on offer where you live. Check fibre coverage and compare the live deals at your address, and if a new term ever trips you up, come back to this glossary.