In New Zealand almost everyone calls the box from their provider “the modem”, but on a fibre connection it is really a router — the modem’s job is done by the white Chorus box on the wall. Knowing which box does what makes troubleshooting faster and helps you decide whether your own equipment would do the job better.
Modem and router: the difference
| Modem | Router | |
|---|---|---|
| Job | Converts the signal on your line (copper, radio or fibre) into a standard internet connection | Shares that connection between your devices, runs the Wi-Fi and protects the home network |
| Connects to | The outside world: phone line, cell tower, satellite or fibre | The modem on one side, your devices on the other |
| Gives out | One public internet address | Private addresses to every device, plus firewall and Wi-Fi |
| On NZ fibre | The Chorus (or local fibre company) ONT does this job | The “modem” your provider sent is actually this |
The word modem comes from modulator-demodulator — the dial-up boxes that turned data into sound on a phone line. The name stuck even though fibre needs no modulation of that kind.
What you have depends on your connection
- Fibre: ONT on the wall plus a router. Your provider’s “modem” plugs into the ONT’s first data port (GE1 on the common ONT 500).
- Copper VDSL or ADSL: a combined modem-router with a DSL port for the phone line. Copper is being switched off by the end of 2028, so this setup is disappearing.
- 4G or 5G wireless broadband: one box with a SIM card that is both modem and router. Our wireless broadband guide covers these.
- Starlink: the dish is the modem and Starlink supplies a router; the Mini has the router built in.
Why the difference matters when things go wrong
Faults on the modem side are the network’s problem; faults on the router side are yours. On fibre, the ONT’s lights tell you which: solid green POWER and PON with the LOS light off means the fibre connection is fine, so the problem is in the router or the Wi-Fi. A red LOS light means the signal is not reaching the house and your provider has to log a fault. Our Chorus ONT guide explains every light, and the internet-not-working guide sets out the troubleshooting order.
When restarting, the order matters: router off, ONT off, wait 30 seconds, ONT on and settled, then the router.
Using your own router
You can replace your provider’s router on fibre with your own — a mesh system or a better Wi-Fi 6 or Wi-Fi 7 router — and most New Zealand providers publish the settings for bringing your own. On Chorus fibre that usually means setting the WAN connection to a VLAN tag (VLAN 10 is the common setting) with the connection type your provider specifies. Check the provider’s own bring-your-own-modem page before you start, and keep the old router until the new one works.
| Reason to bring your own | Reason to keep the provider’s |
|---|---|
| Better Wi-Fi coverage or a mesh system | Provider support will troubleshoot their own equipment |
| Wi-Fi 7 and 6 GHz for Fibre Max or Hyperfibre | Voice services may depend on the provider’s router |
| Advanced features: VPN on the router, better parental controls, VLANs | Current provider routers (Spark Smart Modem 3, One NZ Deco BE28) are already Wi-Fi 6 or 7 |
Router settings worth checking either way
- Change the admin password from the default on the sticker.
- Use WPA3, or WPA2 if older devices need it, with a long passphrase.
- Turn off WPS, UPnP and remote administration unless you need them.
- Keep firmware updated automatically.
- Consider changing DNS on the router — our DNS guide shows how.
Those steps are covered in full in our home Wi-Fi security checklist. If coverage rather than the router itself is the issue, the mesh Wi-Fi guide is the next step, and our home router guide covers choosing hardware.
Disclaimer
General information only. Bring-your-own-router settings differ between providers; follow your provider’s published settings, and keep its router until yours is working.
Reference sources
Frequently asked questions
What is the difference between a modem and a router?
A modem converts the signal on your line into an internet connection. A router shares that connection between devices, runs the Wi-Fi and firewalls the home network.
Do I need a modem for fibre in NZ?
No separate one. The fibre box on the wall does the modem’s job, so you only need a router, even though providers call it a modem.
Can I use my own router on fibre?
Yes. Most providers publish bring-your-own settings, usually a VLAN tag on the WAN port. Keep the provider’s router until yours is working.
Is a modem-router combo a good idea?
On copper and wireless broadband it is the norm. On fibre the “combo” is just a router, and a better router or mesh system can improve Wi-Fi a lot.
Which light shows the problem is outside my house?
A red LOS light on the fibre box. That means the signal is not arriving, so contact your provider.
Does a new router make my internet faster?
It can make Wi-Fi faster and more reliable around the house. It cannot make the connection faster than your plan.
Links mentioned in this article
- Wikipedia (from the previous version of this article)
