A student in Zetland on an Exetel 100Mbps DSL plan with a ZTE router simply could not get online — and could not work out which wall socket the router was supposed to plug into. We sorted it over a video call. The culprit is one many newcomers hit: in some Sydney buildings the internet still runs over the old phone line (DSL), and the phone socket looks almost identical to an Ethernet socket. Plug into the wrong one and you get nothing.
Many people arriving from China have not seen phone-line internet in years, so DSL feels alien. But in parts of Sydney — some older CBD buildings and a number of Zetland blocks — broadband still comes in over the copper phone line using DSL, typically topping out around 100Mbps. That is exactly this student's setup: an Exetel DSL plan, not a fibre or cable connection. The router has to connect to the phone line, through the correct wall socket, or it will never see the internet no matter how many times you reset it.
- DSL delivers internet over the copper telephone line, usually capped around 100Mbps.
- Still in use in some older Sydney CBD buildings and parts of Zetland.
- This home: Exetel 100Mbps DSL plan with a ZTE router.
- The router must reach the phone line via the right wall socket to get online.
The two look similar but are not the same size. The phone/DSL socket (RJ11) is narrower; the Ethernet/network socket (RJ45) is wider. A small RJ11 phone plug will physically fit into the bigger RJ45 Ethernet port — but not the other way around — which is exactly how people plug into the wrong hole and end up with no internet. Two ways to find the right one: look for a wall socket labelled DSL or with a phone icon, or test each socket in turn and watch the router — the correct one makes the DSL/link light go solid.
- Phone/DSL socket (RJ11): smaller and narrower.
- Ethernet socket (RJ45): wider. A small phone plug fits it, but not vice versa — a common trap.
- Look for a wall port marked DSL or with a phone symbol.
- Or test each port and watch for the router DSL/link light to turn solid.
Working over a video call, we walked the student through identifying the DSL wall socket, moved the ZTE router lead into the correct phone/DSL port, and watched the DSL light change from off to solid — the sign the line was locked in. We then set the connection mode on the router and confirmed it was online. To finish, we helped connect the desktop to the router by cable and ran a speed test to confirm it matched the 100Mbps plan. From no internet to a fully working, wired connection, entirely remotely.
- Identified the correct DSL wall socket and moved the router lead into it.
- DSL light went from off to solid — line synced.
- Set the router connection mode; confirmed internet was working.
- Wired the desktop to the router and speed-tested against the 100Mbps plan.
Result
The line was fine and the router was fine — it was simply plugged into the wrong wall socket. Once the ZTE router was in the correct DSL/phone port (RJ11, not the wider Ethernet port), the DSL light locked, the connection came up, and a wired speed test matched the 100Mbps plan. Solved entirely over video.