(Updated) Review: D-Link Cobra DSL-5300 MU-MIMO Wi-Fi Modem Router

In his first look the other day at the new D-Link Cobra AC-5300 modem router, our Ray Shaw was dazzled. “Deadly to slow internet” he said. Now we’ve managed to spend a bit more time with it. What does this $749.95 device give us?


In the world of consumer electronics, you know something’s a serious bit of kit when the power cord is thick and it uses a heavy 3 pin IEC C13 power plug into its power brick, instead of the regular little two pin C7.

That’s the second thing I noticed when unpacking the D-Link Cobra DSL-5300 MU-MIMO Wi-Fi Modem Router. The first thing? The cardboard box. It was heavy, dense, with a lift-off lid, filled with thick foam with individual cut outs for each item, not least the eight antennae. It reminded me of the way high-end audiophile equipment is often packed.

But of course, this is not that. This is a device which performs the vital service of connecting the world to all the individual network devices in one’s home, and all those devices to the world.

And we have so very many of them. A quick inventory of my home (and home office) reveals that at least fifteen devices are connected via WiFi, and a further dozen by means of wired Ethernet. If you start using too many of them at once, especially the WiFi devices, communications start to crawl.

The Cobra is well built and large. On my shelf it consumed a space 400mm wide and 270mm deep, and that’s not counting the additional depth required for the cables. Indeed, despite the bold styling, I ended up installing it backwards, with the ports facing the room and the rather more attractive nose pushed into the wall, otherwise it wouldn’t fit on my shelf.

It’s fairly bristling with antennae. The eight of them reach 125mm above the bench.

The screw connections for the aerials are gold plated. There’s a USB 3.0 port on the back, plus a USB 2.0 port. A phone line port for DSL and an Ethernet port for connecting to an Internet gateway for connection to the rest of the world, while four gigabit Ethernet ports cater for the wired network.

The accessories provided with the Cobra are the all-important DSL line filter, an Ethernet cable and a phone line cable.

It does all the usual stuff you’d expect from a modern high end modem: NBN as well as ADSL, DLNA support, WiFi Guest access, “SharePort web access”, VPN and so on. The special stuff it has is largely related to screaming, raw speed. The 5300 in the model name comes from toting up all the maximums in megabits per second of which the unit is capable. There is not dual band but tri-band WiFi, with one 2.4GHz and two 5GHz bands available. Wave 2 MU-MIMO – Multi User, Multiple Input, Multiple Output – allows for dataflows with multiple users and devices simultaneously. Advanced AC SmartBeam guides the wireless connections for maximum efficiency. SmartConnect switches connections to the best available band.

And while not related directly to data throughput, also speeding things up is the 1.8GHz quad core processor, which manages affairs swiftly.

And finally, a bit of quality assurance. D-Link covers the Cobra DSL-5300 with a three year warranty.

Setting up

The problem with modem routers for most home users is, well, they are scary. Not the looks, although I’m not sure I’d want to see an animated D-Link Cobra in a nightmare. No, it’s the fear that you’ll mess something up. And if you accidently make an error in a setting, and consequently can’t get onto the Internet, your access to help is severely constrained.

The Cobra makes setting up, with no need to dig any deeper, about as easy as it can be, thanks to a simple wizard to guide you through three steps. A clear quick start guide gets you connecting up the minimum of cables – including to the phone network via the line filter/splitter, if necessary – and plugging in your computer. If you prefer, you can use a computer to connect wirelessly. A card in the box has the default WiFi name and password of the particular unit printed on it.

And, most importantly, it’s also printed on the bottom of the modem itself. If things go haywire in your network in a year’s time and you decide you’re just going to have to start again from scratch, they you can press and hold the recessed reset button on the Cobra, confident that you have the keys to access it in its factory default state.

But wizard or not, there were a couple of decisions required of the user. The first was the type of connection – Ethernet WAN, ADSL or VDSL. Mine was ADSL – to which this writer’s Internet is regrettably restricted for at least another year – but for some reason the default selection was on VDSL. After changing that and clicking “Next”, there was country choice (Australia, New Zealand and “Others”). The “most commonly used” ATM PVC (Asynchronous Transfer Mode, Permanent Virtual Circuit) setting was filled in for Australia and New Zealand. I accepted the Australian Default. Then there was the Internet Connection type. The “PPPoE” was set as the default, and the text suggested this was used by most DSL modems. I accepted that.

Then it was just a matter of keying in – very carefully – my user ID and password. You must have this to connect to the Internet. If you don’t have them, contact your ISP. Do that, if necessary, before starting setup.

When I clicked “Next”, I was expected to wait a minute or two while the modem connected to the Internet. But instead, it instantly went to setting up the WiFi network.

Being of a somewhat lazy disposition, and horrified by the thought of all the reconnections that would be required, I simply used the same SSID – WiFi name – that I’d used on the Telstra modem the Cobra was replacing, and on the modem before that as well.

Only one SSID and password was asked for. That surprised me because every dual band access point I’ve used before has provided for two: one for 2.4GHz and one for 5GHz. Later I went digging around in the Wireless settings and found that there was a setting called “Smart Connect”. Switch this off and you can set individual SSIDs and passwords for each band – two for two separate 5GHz connections. Not that I’d recommend it, but that is available if you have some weird requirement.

And that was it. When I clicked the final “Next”, the modem came back almost instantly, saying it was connected to the Internet and that WiFi was set up.

And it was.


Following that was a process of checking that all the stuff connected to my network worked. And, it turned, out, everything bar one thing did work. I did have to pull the power on a couple of network switches, wait a few seconds, and then reapply the power so they’d be aware of the new regime. That the change of router meant a change of network numbering from 192.168.0.x to 192.168.1.x. Devices with the zero in them won’t work in a “1” local area network.

The one device that I didn’t work, and that I have yet to get to, is just an old dual band router that I’ve crippled to work as two WiFi access points. That one has a static IP address, rather than an address dynamically allocated by the Cobra, for reasons I no longer remember. It’ll need me to connect it to a computer by wire to fix that.

I won’t be comparing this router with any other high end routers. Instead, imagine you’re using a bog standard WiFi router supplied by your ISP. And that is what I’ve lately been using, thanks to the previous, higher performance, router – not a D-Link model – doing some weird stuff. So I’m switching from a Telstra router dating from a couple of years ago, the Telstra Gateway Max TG799vac. It’s a seemingly high performance model with Gigabit Ethernet ports and dual band multiple stream WiFi up to 802.11ac standard.

File copy with the old Telstra modem

So, shortly before installing the Cobra, I did a test timing on a single file transfer. That isn’t really testing the Cobra hard, because it’s real advantages come from the simultaneous multiple device support. But I thought it would be interesting.

And indeed, it turn out to be very interesting. Copying across a 2.35GB test file from my network server, which is wired into Ethernet, to my Microsoft Surface Pro 4, which was connected via WiFi, took nine minutes and 35 seconds, which is a speed of about 4MB/s, or 32Mbps. That’s enough to handle an UltraHD stream from Netflix, with a little bit of headroom.

The same file copy with the Cobra

The Cobra? How about 52 seconds? An average speed of around 41MB/s, or over 320Mbps. That’s enough to handle ten UltraHD streams from Netflix. With a little bit of headroom.

The gigabit Ethernet interface worked at gigabit Ethernet speeds. Specifically, copying that same large file from my network via wire, it ran at 113MB/s, or 904Mbps, or ninety percent of gigabit speed.

How about Internet speed? Fact is, it should make no difference. The bottleneck for me is the ADSL connection provided by my ISP. My ADSL speed is a touch over 6Mbps on a good day, much the same as it was in 2006 when the major parties were fighting an election based, in part, on providing faster Internet.

So I was startled to see scores from speedtest.net of around 4.2Mbps download. To the point where I pulled out the Cobra, restored the Telstra (perhaps it had some secret magic settings, I thought, it being the ISP’s own device) and ran Speedtest.com again. And now I was getting 5.26Mbps, then 5.49Mbps. Out with the Telstra, in with the Cobra, and run again. Now it was giving 5.81Mbps and 5.76Mbps.

Which goes to show: when you can’t control all the variables – line congestion from the neighbours? One of the devices at my place downloading a firmware update? Who knows? – you can’t really be certain of your results.

The interface was wonderfully fast. I am quite over the built in web pages on modems taking seconds, or longer, to load. That’s thanks, I imagine, to the fast processor built in.

Nerd confusions

What follows in the next section is more for those who like to get right into the weeds of their network devices. It turned out, there were four puzzles the Cobra presented to me.

Windows 10 Creators Edition apparently doesn’t like the SAMBA protocol on this unit

(See update at foot the end of this review) First, I had trouble configuring the USB to provide access to a hard drive. That’s likely to do with limited and confusing documentation, and the lack of any help screens within the web interface. And a suggestion from Windows 10 that it is using, and I quite, “the obsolete SMB1 protocol, which is unsafe and could expose your system to attack.” Ouch! I shall come back with more when I’ve heard from D-Link.

Second, whenever I edited one of the “Connected Clients” – to give them a name, or reserve their address – all the other “Connected Clients” would disappear from the listing page (although they continued to work). A refresh of the interface page would fix that, but it did seem odd.

A firmware that seemingly wouldn’t upgrade

Third, perhaps that could have been fixed with a firmware upgrade, but I was also confused by that. According to the Web interface, it had version 1.00 installed. When I ran the “Check for New Firmware”, it said that 1.02 was available. I accepted the download and installation, and the device chugged through that for a couple of minutes before announcing success. When it logged on, the reported firmware version was 1.00, with the same date it had had previously. Clicking again on “Download New Firmware” again offered 1.02. A repeat elicited the same result. This time I noticed that the date for 1.02 was actually the day before the installed firmware, so who knows what was happening there.

Finally, there is also a nice statistics page with a tabbed graph that purports to show your sent and received traffic on the Internet, the LAN and the three separate WiFi bands. I’m not sure they were mapped correctly. I used iTunes on the Surface Pro 4 to download a podcast. According to iTunes and my stopwatch and calculator, the download speed was around 166kB/s. According to that graph, nothing was happening on the Internet, nor on any of the WiFi bands. All the action was on the LAN. Except that the Surface Pro 4 was connected via WiFi. I checked connection status, and the Surface Pro 4 was being reported as connected via LAN, even though the Cobra reported its MAC as the WiFi one, not the wired one.


All that said, the D-Link Cobra DSL-5300 MU-MIMO Wi-Fi Modem Router is a great home router with fantastic WiFi and the kind of web interface that doesn’t deter you from wanting to dig in and explore. I love it.


D-Link has come back on the issue of access to a USB drive. Yes, it is to do with SMB (Server Message Block), a network protocol that provides file and print services for Windows clients. The latest versions of Windows have disabled support for version 1. Kind of.

It’s actually still there, but you’ll have to manually re-enable it. It isn’t hard, but you’ll have to tick a box buried in Control Panel.

If you have a recent version of Windows 10, you’ll find that Control Panel is no longer obvious since much of its functionality has been replaced by Settings. But it is still there. It’s under “Windows System” in the list of apps under the button formerly known as “Start”. But I find it easier just to start typing “Control Panel” into the main search box and selecting it.

When Control Panel is up, type “features” into the search box at top right. You’ll see a link to “Turn Windows features on or off”. Click it.

Scroll down until you see “SMB 1.0/CIFS File Sharing Support”. You’ll see that the box next to it is empty. Click on the box to enter a tick, then click “OK”.

Reboot the computer, and the USB drive you have plugged into the Cobra (if you’ve enabled it in the Cobra’s settings) will now be available if you type the IP address, preceded by two backwards slashes, into the address bar of File Explorer window.

If you’re planning on leaving the drive there for the long haul, perhaps for backing up and further file storage, then you’ll probably find it convenient to map it to a drive letter. Right click on the “usb1” folder shown in the window and choose “Map network drive”. Note what drive letter has been assigned and click “OK”. I had to reboot again to make it stick, but it’s nice to have a 2TB drive that was previously languishing unused now accessible and fully usable. I even switched on DLNA, and now it acts as a music server for my home.

But, all that said, I still think that D-Link should consider updating to SMB2. My Synology NAS had no such problem, nor did my WD NAS. And that first Windows message about security is slightly worrisome. If nothing else, it will avoid a lot of the help desk enquiries from people with the latest version of Windows.