Asus RT5300AC - slow wifi speeds

[Neil Rose]

I'd be grateful for some help, please.
I have an Asus RT-AC5300 router, working with a Virgin Media Superhub 3 (in modem mode) on a DOCSIS3.0 cable supply with an "up to 300MBps" speed. I have measured the speed at different times of the day, using speedtest.net, and the download speed varies between 321-240Mbps most of the time, however it drops to as low as 75Mbps at heavy use times.
I have a wired connection to my desktop PC, a Lenovo ThinkStation P300, and this is where I have monitored the majority of my "raw" speedtests.
We have a moderately large property and there are up to 7x iOS devices connected, plus an Amazon firestick, a PlayStation3 and a PlayStation 4, plus 2x other desktop PCs, all of which are connected via wifi.
I've noticed that connection speeds seem to be slowish and have started monitoring speeds at the different wifi clients. With my previous router, an Asus RT68-AC, I was able to get download speeds of up to 175Mbps on my iOS devices (iPhone 7 & 6) using the speedtest.net app.
However, in recent testing with the Asus RT5300, the average speeds by way of this app are between 15-25Mbps, even when standing right next to the router.
In order to address this, I have tried the following:
1. Reset the router to factory default and reset all settings - no improvement
2. Reset a couple of iOS devices - no change;
3. Changed channels on all bands: 2.4, 5(1) and 5(2) - some modest improvement, however hasn't really improved the speed much beyond 25Mbps
4. Removed the RT5300 and replaced it with the RT68 - no change
5. Removed both routers and changed the Superhub3 to router mode - no change in wifi speeds
6. Switched off a wireless telephone located in the same office as the router - no change whatsoever
7. Checked immediate area around the router (which is located in an open setting, on top of a bookshelf near to a central-ish point in the house) for any other potential interference and could not find anything likely to be causing a problem. (Note this is the same location as for the RT68 which previously provided wifi speedtest app speeds of c.175Mbps)
And thus, I am at a loss as to where to go from here.
I'd appreciate any help which could be provided - thank you.

 

[ColinTaylor]

You have eliminated all of your equipment as the source of the problem and even gone back to a previously working setup. So that leaves two possibilities, 1) it's a issue with your ISP, or b) there is a massive amount of wide band RF interference in the area.

Regarding 1), it sounds like you're in an area where Virgin Media have oversubscribed their network. Get onto them and complain, again and again and again. 1st line telephone support (in India) will just fob you off with "Oh yes, it'll be fixed in 24 hours", their standard reply to get you off the phone. If you're lucky it might just be an issue with the signal levels to the modem which can be fixed by an engineer visit.

Regarding 2), this seems unlikely if it's effecting both 2.4GHz and 5GHz. Do back to back tests with a wired client and then a wireless one to make sure that it's not your internet connection that's the bottleneck. Before doing the wireless tests look on the router at Traffic Manager > Traffic Monitor to make sure that there isn't anything else on your network that is downloading anything, like Netflix or PS3 updates. After that start the tests and look at System Log > Wireless Log. Find your wireless client entry and check it's link speed (you'll have to hit refresh a few times).

 

[Neil Rose]

Colin, thank you very much for your very quick reply, and information.
A question comes to mind: can it still be said to be an ISP issue when my bandwidth/broadband speed is so significantly higher than the iOS speedtest results, i.e. the measured download speed with speedtest.net is virtually always in excess of 100Mbps (and commonly 200-300Mbps), whereas the highest speed ever recorded on the iOS speedtest app has been 35Mbps, and typically only c.15Mbps. Can this still be an ISP issue, when I'm not even using their SuperHub3 as a router, only as a modem?
Forgive me, I'm not questioning your expertise or assistance, merely wishing to understand better when I raise the issue with VM.
I have had VM here several times before and I do have the contact numbers for 3x local engineers. To be fair, there are very few VM subscribers in my immediate area and the installation was brand new with the new development of houses where we live, and that was only a road of 14 properties! I was told recently that I was the only VM customer on the 300MBps service in the area - although of course I could argue that for much of the time, I'm actually not on it!!
Many thanks
Neil

 

[ColinTaylor]

Hi Neil,

I understand you questioning whether it's an ISP issue. I agree it does indeed seem contradictory, but you seem to have eliminated everything else. That's partly why I asked you to do the checks on the router before the wireless tests just in case there's something "unexpected" on the LAN interfering with things. I am in no way an "expert" in these matters, but I'm just trying to follow the logic from what you have already done. Any issues on the ISP side will be with their equipment downstream of the modem, so being in "modem only mode" will not make a difference.

Can you try transferring a large file across your LAN, preferably from a wireless device to a wired device? That way you can see whether it's a problem that is specific to internet transfers, or something with your Wi-Fi.

Regarding VM, from what you've said it sounds like it might not be oversubscription then (although the local hub will cover quite a large area). That makes it even more concerning that you're seeing such fluctuations in speed. I'm on 160Mbps with VM and that speed is rock solid, day or night. Even more reason to get them to send an engineer out. Also have a look at the network log of the superhub (http://192.168.100.1/) just in case that's full of errors.

 

[sfx2000]

I have an Asus RT-AC5300 router, working with a Virgin Media Superhub 3 (in modem mode) on a DOCSIS3.0 cable supply with an "up to 300MBps" speed. I have measured the speed at different times of the day, using speedtest.net, and the download speed varies between 321-240Mbps most of the time, however it drops to as low as 75Mbps at heavy use times.

Customer Accounts generally will be rated as speeds "up to..."

CATV/DOCSIS, is a shared medium, so sometimes, it can be lower than that - but most ISP's try not to oversell the bandwidth without knowing they can support it - not just during quiet time, but also during "busy hours"

Sounds like your ISP has oversold the BW on your particular network segment.

FWIW - Business Accounts are generally sold the other way - e.g. a committed minimum bandwidth - which explains why they're pricier and usually lower BW than Customer Accounts.

 

[Neil Rose]

Hi Neil,

I understand you questioning whether it's an ISP issue. I agree it does indeed seem contradictory, but you seem to have eliminated everything else. That's partly why I asked you to do the checks on the router before the wireless tests just in case there's something "unexpected" on the LAN interfering with things. I am in no way an "expert" in these matters, but I'm just trying to follow the logic from what you have already done. Any issues on the ISP side will be with their equipment downstream of the modem, so being in "modem only mode" will not make a difference.

Can you try transferring a large file across your LAN, preferably from a wireless device to a wired device? That way you can see whether it's a problem that is specific to internet transfers, or something with your Wi-Fi.

Regarding VM, from what you've said it sounds like it might not be oversubscription then (although the local hub will cover quite a large area). That makes it even more concerning that you're seeing such fluctuations in speed. I'm on 160Mbps with VM and that speed is rock solid, day or night. Even more reason to get them to send an engineer out. Also have a look at the network log of the superhub (http://192.168.100.1/) just in case that's full of errors

Hi Colin - thanks for your message and sorry that I've not had chance to respond as yet. I've contacted VM and one of their engineers is coming out Thursday. I've been away from the office for a couple of days but will try transferring the file as you suggest.

Thanks again
Neil

 

[Neil Rose]

Customer Accounts generally will be rated as speeds "up to..."

CATV/DOCSIS, is a shared medium, so sometimes, it can be lower than that - but most ISP's try not to oversell the bandwidth without knowing they can support it - not just during quiet time, but also during "busy hours"

Sounds like your ISP has oversold the BW on your particular network segment.

FWIW - Business Accounts are generally sold the other way - e.g. a committed minimum bandwidth - which explains why they're pricier and usually lower BW than Customer Accounts.

Thanks too, sfx2000, for your input - I think you're absolutely right.
Kind regards
Neil

 

[Klueless]

Could also be high packet loss vis-a-vis your ISP service? Might also account for the even slower speeds through WiFi (losing lots of packets at high speed is less detrimental than losing lots of packets at lower speeds)?

Try running something called "PingPlotter" from a wired PC (that you can later connect to WiFi for additional testing) to some remote service. It will run tracerts and a series of pings to all the devices (routers) between you and the remote service. It will also graph the results so you can run it all day and review everything over a beer later. It just might isolate a problem with one of your ISP's routers.

Towards what Colin said you might well be troubleshooting two problems, one with your ISP and one with your own WiFi. Run speed tests between a wireless device and that PC on Ethernet. (I use Netstress from "Nuts about Nets" and set it to 8 concurrent TCP sessions and another 8 UDP sessions. Now I'm not real bright about all this but I get 75 Mbps over 2.4 GHz and 150 Mbps over 5 GHz which confirms your earlier wireless benches and expectations of 175 Mbps are realistic.)

Also as per Colin best to test over a relatively quiescent network. Verify with the Asus builtin real time traffic monitor.

 

[Neil Rose]

Could also be high packet loss vis-a-vis your ISP service? Might also account for the even slower speeds through WiFi (losing lots of packets at high speed is less detrimental than losing lots of packets at lower speeds)?

Try running something called "PingPlotter" from a wired PC (that you can later connect to WiFi for additional testing) to some remote service. It will run tracerts and a series of pings to all the devices (routers) between you and the remote service. It will also graph the results so you can run it all day and review everything over a beer later. It just might isolate a problem with one of your ISP's routers.

Towards what Colin said you might well be troubleshooting two problems, one with your ISP and one with your own WiFi. Run speed tests between a wireless device and that PC on Ethernet. (I use Netstress from "Nuts about Nets" and set it to 8 concurrent TCP sessions and another 8 UDP sessions. Now I'm not real bright about all this but I get 75 Mbps over 2.4 GHz and 150 Mbps over 5 GHz which confirms your earlier wireless benches and expectations of 175 Mbps are realistic.)

Also as per Colin best to test over a relatively quiescent network. Verify with the Asus builtin real time traffic monitor.

Thanks very much for this, Klueless - I shall certainly give it a try and have noted your comments.