Telstra Smart Modem 3 – not all that smart or fast (update after test – network review)

Telstra is now supplying its Smart Modem 3 with a 4G fall-over. It claims it is faster than its competitors’ typical crappy NBN modems.

Telstra’s carefully wordsmithed comparison says it is the fastest NBN modem, but that is deceptive as it is not an ‘apple for apple’ comparison. It is comparing a Wi-Fi 6 AX device (AX speed not disclosed on its website) with lower cost

  • Netcomm FN18Mesh, Wi-Fi 5 AC1600
  • Sagem 5366 LTE, Wi-Fi 5 AC2200
  • Netcomm NL1902, Wi-Fi 5 AC1600
  • TP-Link VR1600V Wi-Fi 5 AC1600

That is like comparing a greyhound with the rest of the field being 3-legged dogs. Bad Telstra.

Second, the Wi-Fi speed from the Wi-Fi device to the router is a rubbish measurement. The more relevant is OOKLA speed test to see what Internet speeds you can get in the same room, at 5 and 10 metres.

UPDATE 22/8/22: Telstra Smart Modem 3 specs – “Trust us – all you need to know” does not cut it!

In our earlier article (which this replaces), we said, ‘Alas, Telstra did not offer us a Telstra Smart Modem 3 to test as we are, by choice, not Telstra users’. We invited Telstra to provide us with detailed specs – it declined.

We got our hands on a Smart Modem 3 (website) and Booster (website – it is not – more later).

It is a dual-band Wi-Fi 6 modem/router with a maximum speed of 2.4Ghz/573.5Mbps (20/40Mhz bandwidth) and 5GHz/2401Mbps (20/40/80/160MHz) or a total of AX3000. It is wrong to compare it to Wi-Fi 5 AC routers that may be typically 433/866Mbps AC1200-16000.

The booster appears to be a 2.4Ghz/573.5Mbps (20/40Mhz bandwidth) and 5GHz/1200Mbps (20/40/80MHz). It connects to the router via Wi-FI 5GHz backhaul or Ethernet cable.

Tests – weaker signal transmission strengths than expected

As a guide, Wi-Fi 6 should give Wi-Fi 6 device connect speeds of a maximum of 5GHz/2400Mbps at 2m from the router and drop to maybe 5Ghz/1200Mbps at 10 metres. All other Wi-Fi 5AC or 4N devices connect at a maximum of 2.4GHz/433 and 5Ghz/866Mbps and also drop over distance.

5GHz Band Test – figures are -dBm signal strength (lower is better) and the reported device/router connect speed in Mbps (higher is better)

Same room2m from the router5m10m
Upstairs (no booster)   
Upstairs (booster)   

What does this mean?

Usually, the -dBM signal strength in the same room should be around -20 (this was -40), reflecting a lower transmit signal strength. It holds well to 5m, then becomes increasingly marginal at 10m (anything above -60dBm is unusable). Read TP-Link Deco X73 DSL AX5400 modem/router – every NBN FTTN user should have one (review). The TP-Link AX modem/router ranges from -19 to -44 dBm – at least twice as strong as the Telstra Smart Modem 3 signal strength.

Placement of this router in the middle of the home is essential to reduce Wi-Fi distances to devices.

Smart Modem 3 Booster – necessary for most homes

Telstra guarantees that with a Booster, you’ll get wall-to-wall Wi-Fi, or you can cancel without further charge.

Telstra needs to learn that a Booster (mesh satellite) is not a signal ‘booster’. To be clear – it is illegal to amplify/boost RF signals (without a license). Telstra’s mesh satellite simply extends the signal it receives by another 10m. Let’s say that the signal strength at the router is 10/10. Placing the mesh satellite 5m away or upstairs may see it get a 5/10 signal strength. It then retransmits that 5/10 weaker signal another 10m (boosts the signal distance – not the strength/throughput).

Without the mesh satellite upstairs (typical two-story home, timber floor/carpet) directly above the router one floor below) signal strength is -60dBm which is verging on unusable. The rest of the upstairs area was unusable. The mesh satellite gave good coverage, but the throughput was about half the comparable router speed.

The reality is that 10m from either the router or mesh satellite saw internet speeds (we tested on a 25/5Mbps Plan) drop to 4/2Mbps.

The mesh satellite can use Ethernet backhaul, in which case it is transmitting a 10/10 signal and transmits the full internet speed. We recommend Ethernet backhaul if you can get your home cabled.

Caveat: We discovered that if you connect a mesh satellite via Wi-Fi, you cannot use 5G/160Hz band aggregation, limiting the router speed to 5Ghz/1200Mbps maximum. In layman’s terms, the Wi-Fi connection uses half the 2400Mbps speed for backhaul.

Two-story or larger homes need at least one mesh repeater

How many devices does it support? We don’t know but suspect it is <20.

No specs are given, but as most IoT devices use the 2.4GHz/573.3Mbps band, the maximum practical number of devices is about 20.

4G fallback – 25/5Mbps DL/UL if you are lucky

According to Ausdroid’s review, 4G fall-over did not work, and they spent several frustrating hours with Telstra support (an oxymoron), and it still did not reliably work.

We found that the Gen 3 modem fall-over times were several seconds resulting in potential lost work

WPA Wi-Fi security

According to Telstra’s specs, it only supports WPA-3, which may mean older WPA-2 and WPA devices (like older iPads) will not connect. In fact, we could not connect a four-year-old Canon inkjet printer and had to update it to a WPA-3 compatible HP Envy Inspire 7220e all-in-one A4 printer (review). That worked. Fortunately, the test home does not have any IoT at present, and their phones and tablets can use WPA-3.


It has two POTs ports for telephones, and you can attach any standard phone or cordless phone to it. But it uses Telstra’s proprietary SIP, which means you cannot use another brand of DSL Modem’s phone ports.

Who makes it?

It is made by French company Technicolor that also doesn’t release specs. We understand it is model Cobra HX DNA0332TLS (Telstra VCNT-8). The Soc may be a BCM63144 (Broadcom BRCM63XX) REV B0. A search does not find this chip. The LTE modem is Quectel SoC (not sure which model). We don’t know the RAM or its FCC ID yet, so we can’t get a closer look at the device.

It uses Technicolor’s HOMEWARE OS. Despite being based on OpenWRT OS, it is locked to Telstra for remote management and updates. We could not find any firmware update option in the router interface.

Support materials

Quick setup guide

CyberShack’s view – Telstra Smart Modem 3 – enough marketing BS, please

It is a Wi-Fi 6 AX3000 modem/router with 4G Fallback. The comparison with other NBN Wi-Fi 5 AC modems is deceitful. It is available only to Telstra NBN customers on a 24-month plan.

As far as a modem/router goes the antenna signal strength is about half that expected, so don’t expect decent throughput more than five or so metres away. You will need a ‘Booster” or three to cover a larger or multi-story home, and you should investigate Ethernet cabling and backhaul.

Frankly, if you have modem speed and coverage issues, this probably won’t do it for you. There are many alternatives. In fact, CyberShack recently published Crappy NBN FTTN Modem – here are a few better ones (guide) so we know exactly what the NBN resellers are doing. But note that these modems cannot support Telstra’s SIP phone, so if you use Telstra Bigpond and want an NBN Landline, you are stuck with its Smart Modem 3 and a two-year contract.