Asus RT-N66U USB as WAN Fails

[geoffs]

I hope I'm posting this in the correct spot - Can't see anything more suitable though.
I have an Asus RT-N66U with a phone as a USB modem while I wait for something better.
It has the latest Asus firmware - 3.0.0.4.374.979.
The following problem occurred with the original firmware and still occurs with the current version.
Everything appears to work OK until I try a large (greater than 50 to 100Mb) file download, then after 50 - 100 Mb it crashes.
It also 'hangs' on complex websites (such as my banking site!) which attempt to open a second window or frame.
Sometimes (and ONLY sometimes) everything works with the USB connection but ONLY when the phone network is very quiet - such as the 'wee small hours'.
Everything works OK if I tether the phone to the computer.
Everything works OK if I use the phone as a WIFI hotspot.
These 'workarounds' disconnect me from the rest of my network and are therefore just that - 'workarounds'.
However these workarounds do point to the router but I am puzzled that nobody else appears to report anything similar.
I don't have another router with a USB port so I can't try that as a test.
Have I missed a critical setting in the router?
Some suggestions please.
Geoff

 

[jlake]

The symptoms that you described are consistent with an MTU problem.

Maybe someone here will tell you how to fix it.

 

[L&LD]

Don't know if it's an MTU problem - but what firmware are you running?

The latest firmware (374.36Beta 1 SDK5) is recommended and will let us work on current issues instead of trying to possibly reinvent the wheel.

Also, maybe the router is not meant to work with just a USB and not WAN connection?

Looking forward to see if this can be solved.

 

[geoffs]

I've quoted the firmware release in my original post and it is the latest on the Asus site.
Although it is not the intended use for the USB port, it is intended for 'backup' use however the settings for using it as the main modem source are provided in the help info.

 

[L&LD]

The Asus firmware is not the latest or the recommended for this router.

Try this from RMerlin.

http://www.mediafire.com/download/ups085eda5s82d1/RT-N66U_3.0.0.4_374.36_beta1-sdk5.zip


Not only is it a couple of months newer - it has many fixes that RMerlin incorporates into his versions. Also - don't worry about the beta label, it is considered stable at this point.


Of course, the issue can be with your phone too? Or even the USB cable?

 

[geoffs]

The phone - working tethered to the computer 'appears' to rule that out.
The cable - I've tried a couple of different ones and they also worked with the computer.
Merlin's software, I've been thinking about that but might wait for a few more comments.
Still appears strange that nobody else has reported similar problems. I've certainly tried every possible arrangement of the symptoms in various searches with no result.

 

[L&LD]

The phone is meant to work with the computer - while the router, is not (a computer).

Did you try the different cables with the router?

Did you try both USB ports on the router? Rebooting the router? Resetting to defaults?

Also, is the phone model a secret? It may help you to get more responses from others (rather than my twenty questions).


Oh, one last thing I can offer at this point: does another type/model of phone do the same thing with your router? That should rule out your specific model.

 

[geoffs]

Good point re phone. I am waiting for a another 'gadget' to try with a different sim and that test may partly answer that question, although I'd question the statement that the router is NOT a computer as I believe they are both running X software they could probably run the same drivers.
Yes, tried 3 cables with the router all with same result.
Yes, tried both ports on the router both giving the same result.
No secret - the phone is a Huawei U8815. OK, not the fastest and smartest however it works in the other configurations.

 

[L&LD]

Thanks for the additions.

With all the info above, hopefully someone can help you.

A (general) computer (to me) runs Windows - while a router is just a 'dumb' electronic machine or very focused (specific) 'tool'. Therefore, they most certainly cannot run the same drivers.

And why I don't doubt the phone works great with the computer but not so great with the router.

 

[geoffs]

Thanks for the help, I can't think of any more questions you can ask!!
Well, my computers don't run Windows (not generally), they run Linux which I believe most routers run under so the drivers certainly could be similar.
Thanks again

 

[stray77]

Enable Dual Wan...

This device supports Dual WAN adapters for a fallback when ISP #1 goes down.
Click WAN in the left column
Click the Dual WAN tab
Enable Dual WAN
Set Primary WAN to USB (default is WAN)
For your setup you don't need the watchdog
As for Routing rules well that depends on your specific setup but likely isn't needed.

Good luck, not sure if it works for a cell phone but definitely should work with a 3G/4G USB Device. Perhaps enabling the watchdog and having it ping an empty WAN port might help if my 1st suggestion doesn't.

 

[geoffs]

Thanks stray77.
I didn't have 'dual WAN' enabled, but did have USB as the primary WAN.
I've tried enabling Dual WAN (as per your suggestion) unfortunately it made no difference.
I'd like some more explanation as to what the 'watch dog' would do and what would be the suggested settings.

 

[stray77]

Thanks stray77.
I didn't have 'dual WAN' enabled, but did have USB as the primary WAN.
I've tried enabling Dual WAN (as per your suggestion) unfortunately it made no difference.
I'd like some more explanation as to what the 'watch dog' would do and what would be the suggested settings.

The watchdog simply pings an external ip of your choice via the primary WAN port and when no response is received, the router assumes that the primary WAN port is down (isp offline) so it then switches to the fallback device. In your case its a usb modem/smartphone however its designed to work with 3G/4G devices. Since you have nothing plugged into WAN it should just force the use of the fallback device at all times. I think it just doesn't support your phone's modem. I've have a Cradlepoint MBR900 with the same 3G/4G fallback support. The device it uses is a Novatel Wireless(TM) Qualcomm 3G COMA (I'm in Canada)
Here's one from ebay for $9.99 the other side says Virgin mobile but this picture is exactly the fallback device my Cradlepoint uses.

 

[geoffs]

Thanks again stray77.
Trying a different device isn't an option, the phone in question is 'my phone' and swapping the SIM in and out just isn't practical.
Why am I using the phone? Well, for my use a plan that gives me unlimited voice, unlimited text and 4Gb (or some months 5Gb) of data for $39.95 a month is unbeatable - if it works!!
I can't see why a phone or a modem should be all that different, as long as you don't try to send emails, talk and watch movies on the phone all at the same time.
So I did some tests using 2 other computers and 2 different browsers (Firefox and Chrome), all done at what I would think is a busy time of the day on the 3G network.
As I mentioned in an earlier post the problem disappears late at night which has led me to think of timing problems.
The 3 computers I used were an Asus M51V laptop about 6 years old, a Toshiba Satellite A100 laptop about 8 years old and an Asus eeePC 1000HE about 4 years old. All have a Linux system (derivatives of Ubuntu) on them and the Asus M51V also has Windows 7 on it. All have both Firefox and Chrome although the Windows 7 only has Chrome.
I tested all of them with the phone tethered directly to the computer and with the phone tethered to the router.
Purely subjective but when the phone is tethered to the computer in all cases it appears to be faster.
All the computers worked perfectly when the phone was tethered directly to them.
All the combinations exhibited the fault when the phone was tethered to the router however some combinations worked sometimes. Whether they worked sometimes or not appeared to depend on the speed of the computer. The faster the computer, the more likely they were to work sometimes.
Chrome appeared to work a little more frequently than Firefox. It appears that Chrome never gives up! The page may sometimes appear after 2 or 3 minutes of waiting. That never happens with Firefox.
I am waiting (it is in the mail!) for a device like the one you mentioned above. I have another data sim card to try in it and that should make some more testing possible.
Do you or does anybody know why there should be a significant speed difference between the direct connection and via the router. I have never previously noticed an obvious difference when adding a router although I've never previously used a USB connection. Clearly the extra link must introduce some delays but these seem excessive.
Must do some ping tests!

 

[geoffs]

I did a quick ping test- just to google.com. Now I am mystified!!
With direct tether to computer - approx average 500ms
With tether to router - approx average 200ms.

 

[stray77]

maybe this will help...

3G/4G USB Adapter Support List

Is your phone on this list?

 

[L&LD]

stray77,

Good link. I didn't realize that it was dependent on router, country, device and carrier - rather a lot of variable elements to come together for it to work correctly, huh? And Canada is not even on any of those lists...

 

[geoffs]

stray 77 and L&LD
No, my phone is not on that list. I had looked at this list previously but I had also seen the explanation that this is a list of devices etc. that Asus have tested or have had tested. There are probably many other devices that will work and I was previously advised 'just try it'. You may find that it will work or as I found, it will ALMOST work.
A work-around that I still have to try is to use the phone as a wi-fi hotspot and 'bridge' a router to it. Not sure that that idea can be made to work - subject for another thread.
Thanks for the help
Geoff