Loosing almost 80% speed through my RT-AC68U.

[Lars Buresø]

Hello.

1. time posting here, and I'm not really good with networking, but I usually get by.



I have used an older Merlin firmware on my ASUS RT-AC68U router for years, and never changed it, as it has just been working for me, and after I got a new IPS (fiber 1GB/ 1GB) I wanted to keep using my router, as it never missed a beat, and my QoS has never had my son come asking if something was wrong with our internet.

So why change a good thing?


The problem now is that I have set my new Zyxel VMG3925-b10b in bridge mode as pr. my IPS guidance, and it's working fine, but only when I have it directly into my PC, the moment I try to use my ASUS RT-AC68U I lose around 80% up and down speed, (125MB/ 125MB) and I have no idea of why.


I have made a backup of my longtime well served Merlin firmware and installed the latest from RT-AC68U_3.0.0.4_384_45149-g467037b.trx but it didn't help one bit, sadly.


If I turn off QoS I get around (250MB/ 250MB), but I don't mind losing a bit of speed for using QoS, the problem is that I'm losing way too much.


I have read about using Jumbo frames, but that didn't work.


I have set IPv6 to Passthrough, and also tried to set it in Native mode, but after speaking to my ISP, they did agree that it needed to be in Passthrough.


I have watch a few YouTube videos but I can't find anything like this, so I thought I could come ask here, as it seems the knowledge of ASUS routers is gathered here.

 

[CaptainSTX]

1. Backup all your settings then do a factory reset using the software switch.
2. Minimally configure your router (password & Wifi if you need it.)
3. Under the LAN tab look for the switch settings and be sure that NAT acceleration is enabled.
4. Test again using a computer connected to your ASUS router with a KNOWN GOOD cable.

If that solves your problem you know one or more of your settings has reduced your speed. The most likely is QOS which did and still might disable NAT acceleration. I can't remember if this issue was ever resolved. In any case with the speed of your connection you probably don't really need QOS as you have more than enough bandwidth.

5. You can try reinstalling your saved configuration file and confirming that NAT acceleration is enabled and see what happens. To enable NAT acceleration might require you to disable QOS.

 

[Lars Buresø]

Thank you CaptainSTX.

I will try that and return with the result.

 

[Lars Buresø]

Well, something was wrong..


I now get 842MB/ 941MB so the speed is much better, still losing a little over 200MB down, but I can live with that.


It's not possible to change NAT to enable; it's sitting on AUTO, with this message in yellow next to it. CTF Cut Through Forwarding) is enabled. I don't know what that does, or how to disable it, or if it's even necessary?


I also tried to enable Adaptive QoS and used the "game" setting and I go down to 469MB/ 468MB speed.


After disabling QoS, I get the same as before again, so it seems I sadly can't use QoS on this router.


If you should recommend a new router that I can use QoS with, that don’t eat up ½ my bandwidth, which one would that be?

Except for a Netgear router, I have not had one of those that worked right for me, and there are also problems on some of them for sim-racers that use the iRacing platform that’s how I know, as I also race there.

 

[Lars Buresø]

I could also skip using my oven router and use the provided Zyxel VMG3925-b10b, but I'm not sure it’s better that my old trusty ASUS RT-AC68U?

 

[Grisu]

Why do you want to use QoS? I think there is absolutely no need for this with 1GB link rates up and down.
Much more powerful and newer hardware for a quite good price would be an RT-AC86U.

 

[Lars Buresø]

I want to use QoS as it has worked so good until now, but I have never had such a fast internet connection as the one I have now, so maybe I just worry to must,

I just remember when I had an ADSL connection many years ago, and I sometimes had to unplug some of the other pc's in the house, as if somebody was checking for new mail would give us a ping around 300ms and big studded when we were playing CS in the old days, and now my son is still playing online fps games, and I'm sim-racing, and none of us want things like that to happen, and we have never had any problems after I bought my percent router and got it setup.

For now, I'll try to still use my router, but without QoS, and see how it's working.

 

[CaptainSTX]

If you really think that you need QOS with your bandwidth on your symetrical gig connection then your best or at least most cost effective solution might be to install a smart switch behind your router. This would also relieve your router's processor of the burden of trying to regulate QOS.

My TP-Link SG108E which I purchased on sale for US$30 has QOS (Port Based, 8021P and DSCP). It also offers bandwidth control by port. I don't know how well these features work or even fully understand all the options as my main purpose in installing this switch was to add multiple VLANS and have VLANS that carried across multiple switches.

For your clients that connect by WiFi you would need to plug an AP(s) into a port and regulate all the clients connecting to the AP with the same restrictions.

 

[Lars Buresø]

I thought I needed it, but from what I have read here, it seems it would never be a problem, so I'm not going to bother with this anymore, unless I experience issues.
I really like my ASUS RT-AC68U, and would only buy a new one, if it would give me any benefit.

I could take a look, and see if the latest Merlin FW is better, but for now it's working.

Thank you for your help.

 

[RMerlin]

CTF is hardware acceleration, and is mandatory for connections as fast as yours.

 

[Lars Buresø]

Thank you for enlighten me RMerlin.

 

[route]

It doesn't matter how fast your internet connection is, if it's possible for an application to use the entire upstream bandwidth than QoS can help. Is it possible for an application to upload at 1Gbps; why not?

Have you tried Traditional QoS? I don't trust Adaptive QoS.

 

[Lars Buresø]

Yes I have, that cut my speed to about 125MB/ 125MB and that's too much.

 

[RMerlin]

Have you tried Traditional QoS? I don't trust Adaptive QoS.

You cannot use Traditional QoS with such a fast Internet connection, the CPU is nowhere fast enough to keep up.

 

[route]

Modern QoS implementations are overly complicated adding unnecessary rate limiting features. Simple outbound priority queues shouldn't require much of the cpu.

 

[RMerlin]

Modern QoS implementations are overly complicated adding unnecessary rate limiting features. Simple outbound priority queues shouldn't require much of the cpu.

It's not that QoS is CPU intensive, it's that QoS requires disabling hardware acceleration.

 

[DummyPLUG]

With 1Gbit connection most if not all consumer router can't handle QoS, firewall at the same time, funny is some business router are cheaper then many gaming router and can handle these easily, such as the draytek 2960 I used for years and my CCR1009.
And they are more stable too.

 

[RMerlin]

With 1Gbit connection most if not all consumer router can't handle QoS, firewall at the same time, funny is some business router are cheaper then many gaming router and can handle these easily, such as the draytek 2960 I used for years and my CCR1009.
And they are more stable too.

They don't document it, but enabling advanced features such as QoS will also kill the performance on these products (when they do have any such advanced features).

 

[Dave Parker]

What version of Merlins firmware are you using? Sounnds like it's very old. Also when you flashed to Asus firmware did you do a factory default reset? If your budget will allow, the AC86U is definitely a step up.

 

[DummyPLUG]

They don't document it, but enabling advanced features such as QoS will also kill the performance on these products (when they do have any such advanced features).

Not quite true, as many of these product also listed their throughput under different condition and most of them are still way better than a consumer router, even after QoS and many of those advanced feature, so it will be easier to predict the performance hit for these business router. But I hardly see a consumer router told me what is the performance hit such as after 10 firewall rules

What I want to point out is for many expensive gaming router its SoC just not as good as many cheaper business router, advance user looking for cutting edge performance will be better look for a business router other than a expensive gamming router, which give you more control, better performance, and usually more stable.