Which AC router class to buy

Until MU-MIMO is certified in 2016, AC1750 is the ticket.

The last time I wrote about routers, I recommended against 802.11ac (AC) devices since the spec hadn’t been ratified at that time. Now that it has, however, a new problem has surfaced: horribly confusing nomenclature in the marketplace, accompanied by astronomical prices.

Why you should buy an AC1750 router

So which AC class router do you buy? Unless you need to bridge networks, get an AC1750 router. You can stop reading here if you want. Below, I’ll explain exactly how that conclusion is arrived at.

All AC routers are dual band, meaning that they use 802.11n and 802.11ac simultaneously. AC router classes are determined by the sum of the router’s maximum link rates (in Mb/s) in both bands. Thus, for example, an AC1200 router is so named because its total maximum link rate in the 802.11n and 802.11ac bands is 1200 Mb/s.

Here’s the trick: the maximum certified 802.11n client link rate is 450 Mb/s. That means regardless of which AC class you buy, you’ll always be limited to 450 Mb/s on the 802.11n band. Similarly, the maximum certified 802.11ac client link rate is 1300 Mb/s.

Clients can use only 1 band at a time, i.e. an AC1300 client like the latest MacBook Pro can use either 1 x 1300 Mb/s 802.11ac band or 1 x 450 Mb/s 802.11n band, but never both simultaneously and never 2 of a kind.

That said, don’t get anything below AC1750 either. You should always get a device with the maximum Wi-Fi certified specs, otherwise you risk leaving useful futureproof performance on the table.*

AC1900 and higher classes

Some models include a 2.4 GHz – the same frequency as 802.11n – 600 Mb/s link rate tier in their ratings, but that link rate isn’t 802.11n compliant and probably never will be either.

There’s also a 1733 Mb/s 802.11ac MU-MIMO link rate tier, but the implementation isn’t certified yet, which makes interoperability iffy. Currently the only way to use the 1733 Mb/s capability is to bridge 2 routers with the same flavor thereof; an expensive option.

Other routers pump up their AC ratings by bundling 2 AC radios into a single router in addition to a 600 Mbps tier. For example, an AC3200 router is 2 x 1300 Mb/s 802.11ac radios + a 600 Mb/s 802.11n radio, priced accordingly. Due to the client limitations mentioned earlier, however, such a router will still give an “only” 1300 Mb/s link rate on an AC1300 client.

TL,DR: Avoid AC1900+ until MU-MIMO is certified, and even then anything above AC2183 is probably just a marketing trick.

For further reading (and also to see where I got the above info from), see SmallNetBuilder here and here, as well as Wikipedia.

*99% of the time when people complain about their Wi-Fi performance, it’s because they bought a lowest common denominator solution that couldn’t keep up with their long term or occasionally more demanding needs. Don’t be one of them.

Netgear WNDR3300 wireless router not working with your cable modem? Here’s how to fix it

Recently I set up a Netgear WNDR3300 wireless router with a Thomson (since renamed to Technicolor) DHG574 DOCSIS 3.0 cable modem on Mediacom. The router had worked perfectly with a previous CenturyLink DSL modem, but was now unable to maintain an internet connection. The Internet LED (the middle one in the above picture) would turn green initially, only to get stuck on amber soon thereafter.

Following the official instructions¬†here only resulted in the same. For some reason, the router acquires a connection upon detection of Dynamic IP, but then loses it in the next step. To fix that, you’ll need to exit the Setup Wizard before it’s complete to prevent the router from borking the connection it detected:

  1. Connect to the router directly using a physical Ethernet cable.
  2. Power cycle the cable modem.
  3. Repeat Steps 1 – 5 only in the above link so that the router indicates that is has a Dynamic IP connection.
  4. Check to see that the Internet LED is green. If it is, proceed to the step 4 below.
  5. Click Basic Settings under Setup in the router admin UI.

    I suspect clicking any sidebar link that takes you out of the Setup Wizard works, but Basic Settings is pretty safe so I'm going with that.
    I suspect clicking any sidebar link that takes you out of the Setup Wizard works, but Basic Settings is pretty safe so I’m going with that.
  6. Exit the router admin UI.

You should now have a stable internet connection with the internet LED remaining green throughout. Unfortunately, all indications are that you’ll have to repeat this process after every power loss to the router and/or connection loss by the modem itself. It’s probably a good idea to get a new router anyway, but if it’s what you have to work with, this will certainly help.