What's new

RT-AC66U - Slow WAN to LAN

  • SNBForums Code of Conduct

    SNBForums is a community for everyone, no matter what their level of experience.

    Please be tolerant and patient of others, especially newcomers. We are all here to share and learn!

    The rules are simple: Be patient, be nice, be helpful or be gone!

prelude

Occasional Visitor
I had a fiber optic connection installed today, which is a 175Mbps/175Mbps service. The ISP provided me with a Sagemcom F@st 2864, which I don't want to use. It took me a while to get the RT-AC66U to work with the new PPPoE connection, but it now works with VLAN 35 set up properly.

My issue is that the Asus can't keep up with the connection. Here are speed tests with the Sagemcom and Asus:

Sagemcom:

eenefJ0.jpg


Asus:

zgWVNeX.jpg



The Rt-AC66U is using the latest firmware from Asus as of today. I just tried Merlin's latest .33 beta, but that actually gave me a worse result: 126/145

Does anyone have any idea what might be causing this? SMB's own review shows 836Mbps/839Mbps for WAN to LAN.

Hope I don't have to buy another router.
 
I had a fiber optic connection installed today, which is a 175Mbps/175Mbps service. The ISP provided me with a Sagemcom F@st 2864, which I don't want to use. It took me a while to get the RT-AC66U to work with the new PPPoE connection, but it now works with VLAN 35 set up properly.

My issue is that the Asus can't keep up with the connection. Here are speed tests with the Sagemcom and Asus:

Sagemcom:

eenefJ0.jpg


Asus:

zgWVNeX.jpg



The Rt-AC66U is using the latest firmware from Asus as of today. I just tried Merlin's latest .33 beta, but that actually gave me a worse result: 126/145

Does anyone have any idea what might be causing this? SMB's own review shows 836Mbps/839Mbps for WAN to LAN.

Hope I don't have to buy another router.

Try resetting the Asus router to factory defaults (clear NVRAM). Search the forum or read your manual if you don't know how to do that. And then try to use as many of the default settings as possible so you don't accidentally disable PPPoE hardware acceleration.

Smallnetbuilder doesn't test WAN to LAN using PPPoE connection. Their test procedure can be found in link below. Since highspeed PPPoE is becoming more popular in Europe, maybe they'll figure out a way to test WAN to LAN using PPPoE connection.

http://www.smallnetbuilder.com/lanwan/lanwan-howto/31103-how-we-test-hardware-routers-revision-3
 
Try resetting the Asus router to factory defaults (clear NVRAM). Search the forum or read your manual if you don't know how to do that. And then try to use as many of the default settings as possible so you don't accidentally disable PPPoE hardware acceleration.

Smallnetbuilder doesn't test WAN to LAN using PPPoE connection. Their test procedure can be found in link below. Since highspeed PPPoE is becoming more popular in Europe, maybe they'll figure out a way to test WAN to LAN using PPPoE connection.

http://www.smallnetbuilder.com/lanwan/lanwan-howto/31103-how-we-test-hardware-routers-revision-3

I've reset it multiple times on both OFW and Merlin's FW. Default setting result in the same problem. So PPPoE requires more overhead? Indicating possible CPU bottleneck on the router?


do you have hardware acceleration enabled?


Yes, it's enabled. I don't have QOS enable either, which would disable it.
 
PPPoE does have a bit of overhead.

Asus added HW acceleration for PPPoE in recent FW releases, so the router should be able to handle your connection.

If you are running my FW, please confirm that nothing is disabling HW acceleration by checking on the Tools -> Sysinfo page.

Otherwise, maybe the fact you have to use a VLAN might bypass the PPPoE HW acceleration? Hard to tell, the HW acceleration module is closed source.

Make sure you don't have the Sagecom still establishing a PPPoE connection in addition to the one configured on your router.

(moving this post to the WIreless-AC subforum BTW).
 
PPPoE does have a bit of overhead.

Asus added HW acceleration for PPPoE in recent FW releases, so the router should be able to handle your connection.

If you are running my FW, please confirm that nothing is disabling HW acceleration by checking on the Tools -> Sysinfo page.

Otherwise, maybe the fact you have to use a VLAN might bypass the PPPoE HW acceleration? Hard to tell, the HW acceleration module is closed source.

Make sure you don't have the Sagecom still establishing a PPPoE connection in addition to the one configured on your router.

(moving this post to the WIreless-AC subforum BTW).

Thanks for the reply Merlin, and for moving the thread to the appropriate sub-forum.

I am running your custom firmware, which actually lowers the speed a little to 125/145 for some reason. Sysinfo page shows HW acceleration is enabled.

OTN ---> Sagemcom = 179/196

OTN ---> RT-AC66U OFW PPPoE + VLAN 35 = 145/165

OTN ---> RT-AC66U Merlin PPPoE + VLAN 35 = 125/145

OTN ---> Sagemcom ---> RT-AC66U handling PPPoE= 49/50

OTN ---> Sagemcom handling PPPoE ---> DMZ RT-AC66U = 179/196


Really at a loss here. Hope I won't have to pick up a new router to rid myself of the Sagemcom!
 
Last edited:
One thing I would double check is the MTU - it might explain the performance drop. Pretty sure the RT-AC66U should be able to handle 200 Mbits on PPPoE, as long HW acceleration is enabled. Also make sure the Sagecom isn't still establishing its PPPoE connection on top of the one from the router. Just to be safe, change the username on the Sagecom to ensure it would fail any attempt at connecting.

It's odd that you get an additional performance hit with my FW over the original one. As long the router does report that HW acceleration is enabled, I would expect performance to be almost identical between both (and possibly even a bit better with mine since I compile a more optimized build of the FW).

Might be interesting to hear from other users who use PPPoE over a fast connection. I know some people in Europe have 200-300 Mbps PPPoE-based connection, no idea how performance look like for them. I only know that Asus recently added HW acceleration for PPPoE, but I never saw any actual numbers to see what kind of gain people were getting out of it.
 
One thing I would double check is the MTU - it might explain the performance drop. Pretty sure the RT-AC66U should be able to handle 200 Mbits on PPPoE, as long HW acceleration is enabled. Also make sure the Sagecom isn't still establishing its PPPoE connection on top of the one from the router. Just to be safe, change the username on the Sagecom to ensure it would fail any attempt at connecting.

It's odd that you get an additional performance hit with my FW over the original one. As long the router does report that HW acceleration is enabled, I would expect performance to be almost identical between both (and possibly even a bit better with mine since I compile a more optimized build of the FW).

Might be interesting to hear from other users who use PPPoE over a fast connection. I know some people in Europe have 200-300 Mbps PPPoE-based connection, no idea how performance look like for them. I only know that Asus recently added HW acceleration for PPPoE, but I never saw any actual numbers to see what kind of gain people were getting out of it.

What exactly should I try changing about the MTU? Sorry, I'm not familiar with it's function.

I'm certain the Sagemcom isn't establishing a connection, as it's unplugged. :D The ultimate goal here is to not use the Sagemcom. I want to use my RT-AC66U directly with the OTN, and toss the Sagemcom in a closet.

You live in Quebec right? If you're ever in St-Jerome I'd be happy to pay you to come and take a look. Alternatively, I'd also be happy to pay you to connect to my PC VIA teamviewer to try and figure this out.
 
If you are using PPPoE, make sure the MTU on the WAN page shows 1480 and not 1500.

Might also be worth powering down the ONT for 5-10 minutes then turning it back on - that often resolves performance issues with cablemodems, so who knows if it might not also do the same with your service. Assuming you can - I have no idea what those ONT actually look like.
 
Hello,
My English is bad so I'll make it short. :eek:

My ips is Orange France (down 300Mb/s up 50 Mb/s)

With Livebox router :
down 284Mb/s and up 47Mb/s

After livebox router -> Automatique IP in Asus RT-AC66U
with Enable HW Accelerator: down 272Mb/s and up 47Mb/s

After livebox router -> Automatique IP in Asus RT-AC66U
without Enable HW Accelerator: down 240Mb/s and up 31 Mb/s

Only Asus RT-AC66U in PPPOE (VLAN 835)
with Enable HW Accelerator : down 161Mb/s and up 26 Mb/s

Only Asus RT-AC66U in PPPOE (VLAN 835)
without Enable HW Accelerator : down 204Mb/s and up 47 Mb/s

PS: Just for information, IPTV is not possible because Orange uses four vlans (838, 839, 840 and 841).
 
Last edited:
prelude

Does anyone have any idea what might be causing this? SMB's own review shows 836Mbps/839Mbps for WAN to LAN.

Same problem here. My ISP is 200/60 Mbps.

I'm almost sure it's FW because with anyone of new ASUS FW 3.0.0.4.372; ...374.130; and ...374.726 there is download restricted bandwidth.

Only with 3.0.0.354 and older FW i can obtain 200 Mbps downloads.
 
I have a similar problem with this router. I'm in college at the University of Georgia and I use the router as my own personal AP and switch because the wireless connections aren't so hot around here and there are only two ethernet ports - I need three.

Directly connected to the wall to a given speedtest.net server I pull over 900 in both directions. Through the router, I pull ~240 down and ~375 up. With Merlin's firmware both of those numbers dropped by about 30mbps.

Can this performance be boosted? Any suggestions?

EDIT: A speedtest result for good measure: http://www.speedtest.net/my-result/3019212531
 
Last edited:
I already have, and saw very little improvement over the latest firmware so I went back to the latest release.
 
I already have, and saw very little improvement over the latest firmware so I went back to the latest release.

Have you looked around these threads careful? Sorry I can't cite any off the top of my head but I know I've seen similar posts from users w/ very high speed fiber connections and usually they are able to come to a positive remedy.
 
OP: At the risk of suggesting something stupid, have you tried feeding the ASUS via ethernet cable from the Sagecom and disabling wlan on the sagecom?

I know it is sub-optimal to have the two devices in-line, but it would allow you to verify that it is the ASUS PPOE handling that is the fault as that would essentially be the major difference from the perspective of your client machine and network performance.

If you still have a performance drop there then I'd look to some other issue on the ASUS.
 
J'ai écrit au support asus pour ce problème, je vous donnerais la réponse prochainement.

I wrote to asus support for this issue, I would give you the answer shortly.

;)
 
I already have, and saw very little improvement over the latest firmware so I went back to the latest release.

We must do the firmware update (with 3.0.0.4.354) taking a few cautions:

- first do a restore to the factory defaults.
- without any connection to the router's WAN port, flash the firmware.
- after flash do not reset the router.

Without any of these mesures, there is not any improvement in WAN/LAN speeds.

stephn666: J'ai écrit au support asus pour ce problème, je vous donnerais la réponse prochainement.

I wrote to asus support for this issue, I would give you the answer shortly.

There are many complaints about this issue around and i think ASUS should already have given an answer to this, specially because AC66U is a top router (with price tag accordingly) and many of users have providers with 200+ Mbps.
 
We must do the firmware update (with 3.0.0.4.354) taking a few cautions:

- first do a restore to the factory defaults.
- without any connection to the router's WAN port, flash the firmware.
- after flash do not reset the router.

Without any of these mesures, there is not any improvement in WAN/LAN speeds.

Thanks for the recommendation. i'll give this one a shot real quick.
 
J'ai écrit au support asus pour ce problème, je vous donnerais la réponse prochainement.

I wrote to asus support for this issue, I would give you the answer shortly.

;)

(French below)
It looks like a PPPoE issue as mentionned on http://forums.smallnetbuilder.com/showthread.php?t=9425
The AC66's BCM4706 CPU (same as N66, single core 600Mhz) seems to be too slow to handle PPPoE at very high speed, as PPPoE cannot benefit from NAT hard accel.
I'm also looking for a good replacement router for my Livebox to handle 300/50 PPPoE Fiber link.
I'm asking if the AC68' BCM4708A (dual core 800Mhz) could handle that.

French:
Il semble que ce soit un problème liée à l'encapsulation PPPoE qui se fait uniquement via le CPU : http://forums.smallnetbuilder.com/showthread.php?t=9425
Le CPU de l'AC66, qui est le même que le N66 est pas assez rapide.
Je cherche aussi à remplacer ma Livebox (Play) par un bon routeur, mais l'AC66 ne semble pas suffisant.
Je me demande si l'AC68 ne serait pas meilleur avec son dual core 800mhz.
 

Latest threads

Support SNBForums w/ Amazon

If you'd like to support SNBForums, just use this link and buy anything on Amazon. Thanks!

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top