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Asus DSL-N66U review

Gordon Kelly




  • Recommended by TR

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Asus DSL-N66U
  • Asus DSL-N66U
  • Asus DSL-N66U 2
  • Asus DSL-N66U 3
  • Asus DSL-N66U setup
  • Asus DSL-N66U ui
  • Asus DSL-N66U 5GHz
  • Asus DSL-N66U 2.4GHz
  • Asus DSL-N66U USB
  • Asus DSL-N66U bundle


Our Score:



  • Superb 802.11n performance
  • Intuitve UI
  • Stylish design
  • Future-proof model


  • RRP close to 802.11ac routers
  • Odd quirk in the setup process
  • Asus still lacks a Cloud platform

Key Features

  • Dual band 802.11a/b/g/n WiFi
  • VDSL2 modem
  • 4x Gigabit Ethernet
  • 1x Gigabit WAN
  • 2x USB 2.0
  • WPS, WPA/WPA2 security
  • AiCloud media sharing
  • Manufacturer: Asus
  • Review Price: £129.99

What is the Asus DSL-N66U?

Do you remember the Asus RT-N66U? It is arguably the best performing dual band 802.11n router currently on the market and predecessor to the superb 802.11ac compatible RT-AC66U. Now Asus is expanding the 66U brand again with a VDSL2 modem packing version of the N66U that is compatible with the latest fibre optic broadband standards.

Interestingly there is a distinct lack of competition in this sector. The Netgear D6300 packs 802.11ac but a modem without support for fibre speeds and the fibre ready FRITZ!Box 3390 has mediocre wireless performance. With the run Asus’ routers are on it can make serious waves.

Asus DSL-N66U 2

Asus DSL-N66U - Design

Somewhat surprisingly the DSL-N66U is a fairly radical design departure from its modem-less predecessor. At 250 x 155 x 65mm and 820g is understandably bigger and heavier, but it also switches from a horizontal to vertical orientation which helpfully reduces the desktop footprint and projects its signal from a higher point. This makes sense given the DSL-N66U also ditches the characteristic extra antennas that give Asus router’s their hotrod look.

Overall we’re fans of the design and what draws equal praise is the quality of construction. Typically routers are a perfunctory collection of thin plastics, but the DSL-N66U has a fixed heavy metal base which makes it look like the company’s EEE Box PCs of yesteryear and keeps it firmly in place.

In addition the extra internals mean the DSL-N66U has none of the hollow feel of dedicated routers while the company’s customary checkered finish looks smart from all angles. The downside to this design is it cannot be wall mounted and in packing the modem the DSL-N66U also requires a separate hockey puck-sized PSU.

Asus DSL-N66U 3

Asus DSL-N66U - Features

Integrating a modem adds significant size and cost so it is a good thing that Asus has gotten the ‘DSL’ part of it right. The VDSL2 modem can handle broadband speeds up to 250Mbit and is backwards compatible with VDSL, ADSL2 plus, ADSL2 and ADSL. All that is out of reach is Virgin’s cable modem standard.

On the WiFi front Asus has also gone for full fat 802.11n with support for 2.4GHz and 5GHz dual bands and a 3x3 internal antenna array. There’s a strong feature set on top of this as well with 4x Gigabit Ethernet, Gigabit WAN (for connecting to a Virgin Media modem if you want), IPv6 compatiblity, WPA/WPA2 and WPS security and a dedicated WiFi on/off button to easily put it into modem mode.

Aside from 802.11ac (the hit and miss EE Bright Box 2 remains alone for now in combining this with a VDSL modem) the only other notable omission from the DSL-N66U is USB 3.0. Asus has added a pair of USB 2.0 ports, but in truth USB speeds over a network have yet to push the boundaries of this standard so it isn’t a big miss.

Furthermore, being an Asus router, the DSL-N66U comes equipped with the company’s AiCloud functionality. This allows users to share media from USB connected storage remotely. This is handy, though it doesn’t compete with Linksys’ more fully fledged Smart WiFi which gives complete access to router settings and WD’s impressive My Cloud.

LGW Bailey

November 6, 2013, 12:14 pm

You mentioned there is no CD but the photo shows a CD with the various connectors and cables. Or is that the US pack?


November 6, 2013, 12:31 pm

This is the same box as the DSL-N55U, apart from the VDSL WAN Port which the N55U doesn't have, BUT the latest firmware allows you to use one of the Gigabit LAN ports as a WAN port for connecting to a VDSL modem.
For those looking for a single box solution for their existing DSL Needs and don't need the VDSL capability (since most Fibre providers supply a modem in any case), the DSL-N55U is a better priced offering at around £85 now.

Gordon Kelly

November 6, 2013, 5:17 pm

Very true, but a crucial part for many is the VDSL modem these days. Fibre is now available to the majority of UK addresses (just!).

Gordon Kelly

November 6, 2013, 5:18 pm

You've slightly misinterpreted this. I said there was 'no need' for a CD to be used in the setup but Asus does provide one if you want to go that route.


November 24, 2013, 11:50 pm

i've been using the asus n55u instead of the original talktalk router which i was given (dlink 2780) its really good, easy set up and use, so im sticking to asus. now that fibre is available my area, im looking to purchase the n66u.


December 3, 2013, 11:20 pm

If I have the Sky Hub with the modem built in (SR102), will this be a viable replacement?


December 6, 2013, 6:01 pm

I had the same issue with finding the login details, however I found them in User Manual included on the CD. Though I wish they had stated that in the quick start guide - would have saved me some setup time.


December 16, 2013, 8:31 pm

i read this review and then ordered the DSL-N66U, the FTTC box is just out side of my house so i get the 76/18Mbps with a Billion 7800n connected to the Openreach modem

using the DSL-N66U i would get 52Mbps, using the DSL-N66U with the Openreach modem i would get 76Mbps i asked Asus about the difference and this was the response.

Dear [Removed]

My name is {Removed} and it's my pleasure to help you with your problem

This is common, if you DSL-N66U, it will do the routing forwarding, and this will reduce litter speed.

Or you can consider to disable both Windows firewall and the Asus router firewall.

Welcome to refer Troubleshooting & FAQ for ASUS products in ASUS website:

[Web address removed]

If you continue to experience issues in the future, please do not hesitate to contact us.

Best Regards,


ASUS Product Support Team

if you have a 80/20 connection this is not the one box soulition you where looking for!

ASUS Support

January 9, 2014, 9:01 am

Hi copex,

Actually other user using service such as BT Infinity Business with DSL-N66U firmware v1.0.6.x, link rate synced as follows, so should be no problem for 80/20 connection. Since you are using Openreach modem, not sure which ISP you have subscribed with, but that ISP should be using BT backbone. Latest DSL-N66U firmware currently is v1.0.6.3 and can be downloaded from the link below. This version includes lots of new features, bug fixes and enhancement. Also includes a built-in DSL Feedback feature, so any issue please report via that function. We apologize that you didn't get a satisfactory answer/solution from our service center. Thanks.

ASUS Support Site

Data Rate Down: 79xxx kbps
Data Rate Up: 19xxx kbps

Paul L.
ASUS Support

ASUS Support

January 9, 2014, 9:05 am

Hi Mark,

Default username and password are both admin, actually besides User Manual, this info is listed on the bottom label of the DSL-N66U. Thanks.

Paul L.
ASUS Support


January 29, 2014, 10:21 am

Nice report guys, currently using a home hub 4 which struggles to send
signal to the bedroom at the back of the house upstairs...
Do you think a wonderful router like this can improve range?


February 2, 2014, 8:52 pm

Avoid like the plague, my connection dropped from 60Mps to under 40Mbps due to frequent disconnections, / full restarts . It even struggles to maintain its own system time.

I am awaiting asus 3rd attempt at support, but I have had top using it, my broadband was becoming unusable for online gaming due to the high degree of interleaving stuck on my line.

Asus should be getting back to me next week, but unless they come back with something better than Reset / new beta firmware then it will be returned to the buyer and a draytek unit in its place.


February 3, 2014, 4:03 pm

Sort of agree with you David. It was easy to set up and linked to my
regular ADSL line at the expected speeds. The wifi range is indeed very
good but my issue was that it failed to work with my AirPlay speakers
so I am not able to stream music from my ipad/iphone to either of the
AirPlay speakers...

Did send a note to Asus today via their
router's feedback form but haven't heard yet - Not sure what else to try
but its in the box now and will have to send it back to Dabs ...

can see Asus have issued a firmware update in January and there is also
a new BETA available to try, clearly issues there they are working on
but as per January 2014, this product is just not ready for action.


February 6, 2014, 7:41 am

While I haven't noticed any instability issues or poor sync performance one item, which is of high importance for me, is missing.

This device has woefully inadequate IPv6 support. It seems to only support IPv6rd which is an IPv6 over IPv4 tunneling solution. I consider ASUS's advertisement of IPv6 "support" to be patently misleading.

My ISP (O2 Czech Republic) provides fully native IPv6. Without using native IPv6 I'm stuck behind multiple layers of NAT'ting.

Don't be misled by the product name either. Unlike the robustly sized internal hardware of the RT-N66U the DSL-N66U is significantly shorter in terms of flash storage space (16MB vs. 128MB) and RAM (128MB, evenly split between modem and router, vs. 256MB on the RT-N66U). With this paltry flash memory I wouldn't expect much in terms of future extensions of capabilities.

It's a nicely built feeling device and friendly enough to administer. However, it's not all that it says it is and I'm disappointed with it.


February 6, 2014, 10:02 am

CS sent a reply - the router is not compatible with Airplay / Bonjour. Thanks for highlighting the spec differences Gulp, I am sending this router back and my advise to others is not to buy it until they release a firmware update that makes the thing work.


February 9, 2014, 10:43 pm

What is the average power consumption of this unit?
- I asked Asus customer service, but they would not answer my question... very disappointing :-(

Specs says "DC out: 19V / 3,42 A" this equals 65 W out, which probably means 75+ W in.

75W power consumption is ridiculous high!!!

Can anyone please put on a "Watt-meter" to measure it?

ASUS Support

March 24, 2014, 11:47 am

Hi Niels777,

That's a false statement, for other N900 WiFi routers consume around 10 watt at idle status, consider DSL-N66U includes built-in xDSL modem, power consumption around 12 ~ 13 watt.

In addition, firmware with power saving mode feature will be released later. Thanks.

Paul L.
ASUS Support

ASUS Support

March 24, 2014, 12:05 pm

Hi Xman,

Sure DSL-N66U is compatible with AirPlay/AirPrint which based on Apple's Bonjour protocol. No matter Apple TV, Airport Express, AirPlay capable Speaker or Printer that supports AirPrint(via iPad, iPhone etc), all works with DSL-N66U. However if encounter any issue, feel free to submit a report to us via the firmware built-in DSL Feedback feature, then we will look into it ASAP.

By the way, if you are having issue with iTunes Home Sharing, then please go to Advanced Settings > Wireless > Professional, and Enable IGMP Snooping for both 2.4GHz and 5GHz band(this option is disabled by default). Thanks.

Paul L.
ASUS Support

ASUS Support

March 24, 2014, 12:15 pm

Hi gurple,

Well DSL-N66U do supports virtual memory(swap), once USB disk plugged in 256MB of memory will be created. Regarding flash concern, this model using 16MB SPI flash(for xDSL modem router side) now used around 14.xMB there are plenty of new features that will be added and there is no need to concern about future extensions, for USB applications can be installed to your USB disk from our server via IPKG approach, so no worries.

We continue to release updated firmware, that include new features, bug fixes and enhancements on regular basis, any issues or comments feel free to report via firmware built-in DSL Feedback feature. Thanks.

DSL-N66U Support Site

Paul L.
ASUS Support

ASUS Support

March 24, 2014, 12:17 pm

Hi Xman,

Now the firmware is much fine tuned, perhaps you should try the latest firmware.. Thanks.

Paul L.
ASUS Support

ASUS Support

March 24, 2014, 12:24 pm

Hi David,

This probably due to your house phone line issue, better get ISP to check it(I suppose BT?). If ISP cannot fix or not willing to fix it, we do offer Stability Adjustment (VDSL) tweaking feature in latest firmware that could solve this kind of problem.

As for the system time, full restarts concern indeed it's a bug and would occur in some cases and already fixed with latest firmware, my apologies. Thanks.

Paul L.
ASUS Support


March 27, 2014, 6:21 pm

I asked Nordic (Scandinavian) customer service about power consumption and power saving mode. They (Alf) wouldn't or couldn't answer the question, which I told them was quite disappointing.

I'm very happy, that you finally answer.

Thanks a lot.


April 5, 2014, 2:19 pm

After spending three hours trying to set up the damned load of junk, it was showing it was connected to my ISP but none of my computers would talk to the internet but were happy talking to each other, I boxed it up ready to send back to Amazon. I have now reconnected my Netgear DG834N and will put up with a few "drops" until I order another Netgear machine.

Perhaps Asus should stick to motherboards!

Trevor Henley

April 17, 2014, 9:08 pm

had same issue....

Johann GT

May 21, 2014, 8:38 am

The VPN configuration doesn't seem to be like the router RT-N66U. Impossible
to select PPTP connexion in the WAN parameters in the internet connexion

Choose possible :
Ethernet WAN

I bought this router to use internet trought a pemanente VPN connexion.
Please update the firmware as soon as possible.

A VPN client is a basic fonction for all routers. I'm realy disapointed.


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