Never-offline internet: phone hotspot and 5G backup

UniFi can switch to a backup internet connection by itself when your main one drops, then switch back when it recovers. Network 11's WiFi Uplink makes a phone hotspot that backup on gateways with built-in Wi-Fi. The UniFi 5G Backup adds a 4G/5G mobile link from any PoE port.

Pick your backup

Option A: Phone hotspot with WiFi Uplink

You'll need:

• A UDR7, UDR-5G-Max, Express 7 or UCG-Industrial; gateways without Wi-Fi can't do this. The Express 7 needs UniFi OS 6 first, so check its Updates page.
• UniFi OS 6.0.10 or later.
• Network 11, ideally 11.0.94 or later, which improves WiFi Uplink status reporting and stops its radio from being switched off.

Steps:

1. On your phone, turn on the hotspot. Disable its auto-off setting and keep the phone on charge.
2. In UniFi Network, add a new WAN connection and choose WiFi Uplink. Ubiquiti hasn't published the exact path; WAN connections live under Settings › Internet.
3. Pick your hotspot, or type its name, then enter the password.
4. Keep your wired connection as the primary. The Wi-Fi uplink then fails over like any other WAN.
5. If your mobile plan has a data cap, turn off any automatic speed tests on that WAN.

Ubiquiti's release notes call the feature a backup, while its blog says it can be primary or backup. Hotel-style captive portals aren't confirmed to work.

Option B: UniFi 5G Backup

You'll need:

• The UniFi 5G Backup in its worldwide model (U5G), not the US model (see below). It's powered by PoE.
• A nano-SIM with a data plan from an Australian carrier.
• Network 10.4.57 or later.

Steps:

1. Insert the nano-SIM. If the carrier isn't recognised automatically, enter its APN in the device's settings after adoption.
2. Plug it into any PoE port on your gateway or a switch, wherever the signal is best. It reaches the gateway through a tunnel, so it can sit by a window rather than beside the gateway.
3. Adopt it in UniFi Devices and keep it powered while it updates its firmware.
4. Set a data limit and a warning in the device's settings, so a long outage doesn't use up your plan.
5. Optionally keep guests and IoT off the backup: go to Settings › Networks › [network] and turn off UniFi Cellular Internet Backup.

It uses 5G RedCap where the carrier supports both standalone 5G and RedCap, and LTE otherwise.

Backup internet in Australia

Choose the worldwide model (U5G). Australia's main 4G band is 700 MHz (band 28), and the US model (U5G-US) doesn't support it, or bands 1 and 3. The worldwide model lists band 28 and every other 4G frequency in the table below, plus n26, the band Telstra uses for RedCap. Ubiquiti quotes peaks of 195 Mbps down on 4G and 220 Mbps on 5G RedCap. Its spec lists CE certification only, so confirm Australian (RCM) approval with your supplier. The 5G Max and 5G Max Outdoor also list band 28; our 5G Max guide checks them against each carrier.

Starlink suits regional homes as a backup, because it doesn't depend on mobile towers.

1. Connect it by Ethernet to your gateway's spare WAN port, using the port or adapter Starlink provides for your kit.
2. Turn on bypass mode in the Starlink app. Only a factory reset turns it off again.
3. Set the WAN to DHCP.
4. Plan for no public IP. Ubiquiti notes that Starlink connections often lack one, so use Teleport for remote access (see our remote access guide).

Starlink's Critical Information Summaries list its Australian plans, including Standby Mode, a low-cost option that keeps a slow (under 500 kbps) connection.

Set up failover (any backup)

WAN failover: health checks decide when to switch

By default, a WAN counts as down when two of three checks fail: a ping to ping.ui.com, and DNS lookups of ui.com through 1.1.1.1 and through 8.8.8.8.

• Mode: in your WAN settings under Settings › Internet, choose Failover or Load Balancing. Failover uses the backup only while the primary is down; load balancing splits connections by weight, such as 80/20, pinning each connection to one WAN. UniFi supports up to 8 WANs.
• Custom health checks: go to Settings › Internet › Create New SLA. Set the type (Ping or DNS), server, interval, time period, loss, latency and jitter thresholds, and how many servers must fail.
• Pinning traffic to one WAN: add a policy-based route for that traffic, and turn the route's Kill Switch off so it can still fail over if that WAN drops.

Check it worked

1. Note your public IP (search "what is my IP").
2. Start a continuous ping to 1.1.1.1 (ping -t 1.1.1.1 on Windows, ping 1.1.1.1 on a Mac or Linux), then unplug the primary WAN.
3. After a short gap, pings resume and your public IP changes to the carrier's or the phone's. Open sessions, such as video calls, may need to reconnect.
4. Plug the primary back in. Traffic moves back once its health checks pass.

Watch out for

• Power cuts. If the switch powering the U5G loses power, so does your backup. Put the modem, gateway and that switch on a UPS.
• Heat. The U5G is rated to 40 °C, and a sunny window can get hotter than that in an Australian summer.
• SIM quirks. Some SIMs need their APN entered manually, and the unit falls back to LTE wherever 5G RedCap isn't available.
• Phone hotspots switch off. Test overnight before relying on one.
• Data use. Video streaming uses data quickly, and carriers may slow tethered data.
• No inbound connections on backup. Mobile and Starlink connections often lack a public IP, so port forwards and inbound WireGuard won't work; Teleport still does (see our remote access guide).
• Two ways to connect. Ubiquiti's guide also describes a Primary WAN mode, with the U5G plugged into the gateway's WAN1 or WAN2 port; this tutorial uses the simpler LAN-connected backup.

Sources: Network 11 announcement · Network release notes · WAN failover · 5G and LTE backup best practices · UniFi 5G Backup announcement · Public access to local resources · Telstra network FAQ · Telstra certified IoT devices (PDF) · Optus 3G changes · Optus RedCap test · Vodafone network frequencies · Starlink Gen 3 router guide (PDF) · Starlink Standby Mode summary (PDF)

Disclaimer: This guide reflects UniFi software and official documentation as of 22 October 2026. Menus, features, plans and policies change, so check each step on your own equipment and back up first. It's general information, not legal advice, and you use it at your own risk. UniFi is a trademark of Ubiquiti Inc., and other names belong to their owners.