RT-AC68U bandwidth limitations

[jamesnmandy]

Backstory:
So we have been on a 100mbps connection for some time now. Everything worked great on the network, wireless and wired all hitting the full available bandwidth. Recently our ISP upgraded everyone on this level plan to 500mbps. Great!

But ever since the upgrade I have pretty much never gotten 500mbps. A few times 450-470mbps, but more often than not in the 300mbps range. Now of course this was all on the same modem (SB6183 Arris Docsis 3.0). So I had the cable co out to troubleshoot. They cannot find any issues with the line, etc....so they hypothesized the modem was to blame even though that modem is a 16x4 theoretically good for 686mbps.

So they upgraded me for free to the Technicolor TC4400 which is the new "standard Docsis 3.1 modem we install for all 500+mbps customers" for no cost. Great! But it didn't seem to do much, we still struggle to get over 400mbps and not with any consistency. I see as low as 100mbps recently even, but 300mbps seems to be the standard.

So I had them back out, and they hooked their laptop to the modem direct and I watched them pull over and over 500mbps tests consistently. So I hook up my desktop with gig ethernet wired to their modem with the guy there, and it pulls 300-400mbps over and over. He says, maybe I need to update firmware/drivers for NIC. I stay on top of that stuff, I have confirmed I am on all the latest. So then I connect my Nvidia Shield direct and test, 350-400mbps.....so now I'm like, its not the device, also tried same cable he was using to rule that out. He shrugs and says he doesn't know how an Android device would or would not impact things.....

I have tried multiple other devices, wired direct to modem, wired to the router switch, wireless devices.....nothing in my house can connect and get 500mbps but I do get close going direct to the modem.

So as it stands right now, anything connecting through this router seems to be unable to get much better than 300mbps on any connection type. I have updated firmware, actually running Merlin's latest stable 384.7_2 firmware. I run all kinds of customizations but it's nothing I haven't been running for a long time now. I have tried disabling all jffs/cron jobs like Skynet and Diversion to be sure they aren't a factor. I have everything set up on static IP's on the LAN using the MAC filtering to only allow specific devices. I've reset the router to factory and reloaded everything......Nothing is helping.

I have also noticed recently the wifi signal kicks in and out briefly over and over all night to the various wireless devices. We do use the router heavily with a good 14 or so devices connected at any given time. Maybe half wireless, half wired. I have a Netgear GS105E 5 port switch connected to one of the Asus router switch ports to provide more wired connections and it is full as well. Jumbo Frames are enabled across all devices.....I'm just kinda at a loss..

Has this modem maybe just reached it's capacity and is choking on all the demand? We regularly stream HD and/or 4k video to multiple devices simultaneously. I do feel like maybe I need to just upgrade to something a bit more professional if it sounds like the AC68U just isn't up to the task. Several of the wireless devices are 3x Note8's and an iPhone XS Max I believe are MU-MIMO capable but I do not believe the AC68U is so maybe upgrading to one that is would help alleviate some of the network congestion at least on the wireless side?

Sorry for the rambling.....

Cliff notes:
AC68U, current firmware (Merlin), external switch, 14+ devices (wired&wireless) connected, no devices are able to hit the modem provided 500mbps bandwidth and wireless is sometimes on/off momentarily. DIrect connection to modem with some devices can hit 500mbps but not all mysteriously.

 

[Grisu]

if you reload settings after factory reset its just the same as to do simply nothing!
You have to configure manually only most relevant settings (no jumbo a.s.o.) and test again. Set bandwith to 80GHz on 5G to get full possible Wifi speed and NAT-acceleration on.

 

[ApexRon]

So I had them back out, and they hooked their laptop to the modem direct and I watched them pull over and over 500mbps tests consistently. So I hook up my desktop with gig ethernet wired to their modem with the guy there, and it pulls 300-400mbps over and over. He says, maybe I need to update firmware/drivers for NIC. I stay on top of that stuff, I have confirmed I am on all the latest. So then I connect my Nvidia Shield direct and test, 350-400mbps.....so now I'm like, its not the device, also tried same cable he was using to rule that out. He shrugs and says he doesn't know how an Android device would or would not impact things.....

This is important. Your devices should get 500Mbps when attached directly attached to cable modem. I have Spectrum cable 200Mbps service with my own Netgear CM600 cable modem. When my MacBook Ethernet is plugged directly into cable modem, I get 230Mbps with a 200Mbps service. I use an ASUS RT-86U running Merlin and get 230Mbps on my MacBook whether Ethernet or WiFi connected to router.

Moving on, chose one of your Ethernet devices that consistently gets 350-400Mbps when plugged into the cable modem. Connect your ASUS router to the cable modem and plug your device into the Ethernet of the ASUS, removing all other Ethernet connections and don't be actively using any WiFi devices. Your device's speed test should be virtually the same as if plugged into the cable modem. Propagation delay through the ASUS should be negligible. If it is not, then you have a problem with the ASUS hardware, firmware, or configuration. If the speed test results in the same speed, then plug in the remaining Ethernet devices and retest. Again, expect the same speed.

Once you validate the speeds through the ASUS using Ethernet, then we can troubleshoot the more complex issue of WiFi speeds.[/QUOTE]

 

[Datalink]

Fwiw, the 68U will top out around 910 to 920 Mb/s on an IPV4 speedtest with just the Firewall, AI Protection and wifi running (wifi idling). Thats with all other functions deliberately disabled, including Jumbo Frames and IPV6. I'd recommend stepping thru all of the General and Advanced Settings and their various sub-selections, disable everything except for the Firewall and possibly AI Protection if desired. Reboot the router after that is done. Disable Jumbo Frames in the test pc's ethernet adapter and reboot the pc. Then run a wired speedtest to see what you get for results.

If you run a speedtest on a wired Windows pc and still end up with low results, consider running the Ubuntu demo.

1. Download Ubuntu 18.10 from https://www.ubuntu.com/download#download
2. Burn that to a DVD if desired. Right click on the file and select Burn Disc Image: or
3. Download Rufus from https://rufus.ie/en_IE.html
4. Create a bootable USB drive using Rufus: https://tutorials.ubuntu.com/tutori...6.697602217.1542907164-204380586.1542907164#0
5. Start the pc and select the DVD or USB as the boot drive (for this test session) to boot to the Ubuntu demo.
6. After the Ubuntu desktop is displayed, login in. There is no password.
7. Use Ctrl+Alt+T to bring up the terminal.
8. Type in: sudo ufw enable Thats just to ensure that the firewall is up and running. https://help.ubuntu.com/lts/serverguide/firewall.html.en
9. Start Firefox and run a few speedtests to see what the results are.
10. When finished, shut down the demo, the controls are in the upper right hand corner, remove the DVD or USB and reboot back into Windows.

The test results you see with the Ubuntu demo will probably be higher than the results with Windows. That's what I would expect to see at this point. The first step is to run the router with no functions running other than the firewall, and then depending on how that turns out, consider running the Ubuntu demo. Do you already have anything that runs Linux or some variant of it that you can use for test purposes?

There is a way to run a command line speedtest with Linux and I presume Ubuntu, but, that appears to be with Linux or your preferred Linux flavour loaded on a pc. For the purposes of looking at test rates in your situation, running the Ubuntu demo and using Firefox to run speedtests should suffice for now.

 

[jamesnmandy]

if you reload settings after factory reset its just the same as to do simply nothing!
You have to configure manually only most relevant settings (no jumbo a.s.o.) and test again. Set bandwith to 80GHz on 5G to get full possible Wifi speed and NAT-acceleration on.

This is important. Your devices should get 500Mbps when attached directly attached to cable modem. I have Spectrum cable 200Mbps service with my own Netgear CM600 cable modem. When my MacBook Ethernet is plugged directly into cable modem, I get 230Mbps with a 200Mbps service. I use an ASUS RT-86U running Merlin and get 230Mbps on my MacBook whether Ethernet or WiFi connected to router.

Moving on, chose one of your Ethernet devices that consistently gets 350-400Mbps when plugged into the cable modem. Connect your ASUS router to the cable modem and plug your device into the Ethernet of the ASUS, removing all other Ethernet connections and don't be actively using any WiFi devices. Your device's speed test should be virtually the same as if plugged into the cable modem. Propagation delay through the ASUS should be negligible. If it is not, then you have a problem with the ASUS hardware, firmware, or configuration. If the speed test results in the same speed, then plug in the remaining Ethernet devices and retest. Again, expect the same speed.

Once you validate the speeds through the ASUS using Ethernet, then we can troubleshoot the more complex issue of WiFi speeds.

Fwiw, the 68U will top out around 910 to 920 Mb/s on an IPV4 speedtest with just the Firewall, AI Protection and wifi running (wifi idling). Thats with all other functions deliberately disabled, including Jumbo Frames and IPV6. I'd recommend stepping thru all of the General and Advanced Settings and their various sub-selections, disable everything except for the Firewall and possibly AI Protection if desired. Reboot the router after that is done. Disable Jumbo Frames in the test pc's ethernet adapter and reboot the pc. Then run a wired speedtest to see what you get for results.

If you run a speedtest on a wired Windows pc and still end up with low results, consider running the Ubuntu demo.

1. Download Ubuntu 18.10 from https://www.ubuntu.com/download#download
2. Burn that to a DVD if desired. Right click on the file and select Burn Disc Image: or
3. Download Rufus from https://rufus.ie/en_IE.html
4. Create a bootable USB drive using Rufus: https://tutorials.ubuntu.com/tutori...6.697602217.1542907164-204380586.1542907164#0
5. Start the pc and select the DVD or USB as the boot drive (for this test session) to boot to the Ubuntu demo.
6. After the Ubuntu desktop is displayed, login in. There is no password.
7. Use Ctrl+Alt+T to bring up the terminal.
8. Type in: sudo ufw enable Thats just to ensure that the firewall is up and running. https://help.ubuntu.com/lts/serverguide/firewall.html.en
9. Start Firefox and run a few speedtests to see what the results are.
10. When finished, shut down the demo, the controls are in the upper right hand corner, remove the DVD or USB and reboot back into Windows.

The test results you see with the Ubuntu demo will probably be higher than the results with Windows. That's what I would expect to see at this point. The first step is to run the router with no functions running other than the firewall, and then depending on how that turns out, consider running the Ubuntu demo. Do you already have anything that runs Linux or some variant of it that you can use for test purposes?

There is a way to run a command line speedtest with Linux and I presume Ubuntu, but, that appears to be with Linux or your preferred Linux flavour loaded on a pc. For the purposes of looking at test rates in your situation, running the Ubuntu demo and using Firefox to run speedtests should suffice for now.

I know the 5g wireless is set to 80Mhz, I did check that. I guess I should start with a naked default configuration and a single wired device that is known to test properly sans router.

I can setup a Linux environment to perform the test described.

Does anyone think there is value in simply loading the Asus supplied factory firmware instead of Merlin firmware as a starting point?

Thank you for all of the thorough well thought out responses. Based on the responses it sounds like it shouldn't be a fundamental limitation of a correctly configured and operating AC68U router.
It will take some time to prioritize and then try out the various suggestions. Please don't take any lapses in responses as a lack of respect for the input you provided.

 

[Datalink]

One thing I forgot to mention, that 910 to 920 Mb/s thru an RT-AC68U is with a pc connected to the 68U via ethernet cable.

Only item to remember on loading any firmware, including stock Asus firmware for test purposes, load the firmware and then run a factory reset to wipe out any previous settings. With a clean start, and the vast majority of functions disabled, followed by yet another reboot, you should be able to max out your internet plan speeds plus whatever % the ISP allows for over-provisioning. When in doubt, loading Asus stock firmware is a valid comparison point. Basically, leave no stone unturned.

Running a Linux based test should take any Windows issues out of the picture.

And .... try different browsers as well. I use Firefox at the moment for running speedtests, but, previously, Microsoft Edge showed better results, so, this seems to be moving target as browsers are updated. The command line test using Linux should produce clean results (I'm assuming). Its on my list of items to try one of these days.