Help!!! Asus 4G-AC68U keeps dropping connection

[charsiufan]

I have a new Asus 4G-AC68U. The problem I have is it intermittently keeps disconnecting the 4G Wan link.

I had no issues for around 2 years. About a year ago the 4G box would drop the 4G connection and just show as disconnected. If I check the WAN status it will show 'connecting' and then work again. Or if that fails, a reboot of the box will get the link working.

The super frustrating thing is it might work fine for a week, or disconnect 4 times in an hour. I know its not the box because this is the 4th box I have tried over the last 12 months (including 2 TP-Link boxes) - all with the same issue. I have updated the firmware on this box.

I have spoken with the cell company and they say there is no issue with the tower I am connecting to. Any ideas on how to further trouble shoot this issue? Been driving me nuts for the last 12 months.

 

[L&LD]

I have a new Asus 4G-AC68U. The problem I have is it intermittently keeps disconnecting the 4G Wan link.

I had no issues for around 2 years. About a year ago the 4G box would drop the 4G connection and just show as disconnected. If I check the WAN status it will show 'connecting' and then work again. Or if that fails, a reboot of the box will get the link working.

The super frustrating thing is it might work fine for a week, or disconnect 4 times in an hour. I know its not the box because this is the 4th box I have tried over the last 12 months (including 2 TP-Link boxes) - all with the same issue. I have updated the firmware on this box.

I have spoken with the cell company and they say there is no issue with the tower I am connecting to. Any ideas on how to further trouble shoot this issue? Been driving me nuts for the last 12 months.

I am not familiar with this model but have you ever performed a full reset to factory defaults on it? Then manually and minimally configure the router to secure it and connect to your ISP? Do not use a saved backup config file.

 

[charsiufan]

Yes, many times and reconfiged from scratch. As it's the forth box with the same issue I'm thinking something on the network is causing this or an issue with the tower but how to diagnose?

Any advise appreciated.

 

[L&LD]

Are you using an actual cell phone with this or a sim card? Is the sim card damaged? Does it need to be updated (somehow)?

 

[charsiufan]

Yes. Many times across 4 boxes.

Trying to figure out what would make a router 'choke' and need a reset so often.

 

[charsiufan]

All routers have a sim slot. I've tried multiple SIMS. I don't think it's a hardware fault per say, but external factor could cause a router to 'hang' repeatedly and need a reboot?

Are you using an actual cell phone with this or a sim card? Is the sim card damaged? Does it need to be updated (somehow)?

 

[L&LD]

Yes. Many times across 4 boxes.

Trying to figure out what would make a router 'choke' and need a reset so often.

I don't think you answered post 4?

Can you detail how you do a reset on the router for us?

 

[charsiufan]

No. The boxes have a sim slot integrated into the devices.

Are you using an actual cell phone with this or a sim card? Is the sim card damaged? Does it need to be updated (somehow)?

 

[charsiufan]

Sorry, forgot to answer that.

3 ways...

1. There is a factory default option in the router administration interface

2. There is a small button on the back that needs a paper clip to reset the box.

3. The vendor gave me a new box to try.

Didn't help unfortunately.

I don't think you answered post 4?

Can you detail how you do a reset on the router for us?

 

[L&LD]

Sorry, forgot to answer that.

3 ways...

1. There is a factory default option in the router administration interface

2. There is a small button on the back that needs a paper clip to reset the box.

3. The vendor gave me a new box to try.

Didn't help unfortunately.

1. Is there also an option to 'Initialize all settings...' too?
2. Have you used the WPS NVRAM erase process?
3. If you upgraded the firmware, then a full reset is still required.
4. Is your ac power grid stable? Do you have a quality UPS for the router?

To get your router to a good/known state, simply using the GUI or the reset button method may not be enough.

1. Remove your sim card.
2. Reset to factory defaults. Use the 'Initialize all settings...' checkbox button too, if available.
3. When the router reboots, do a quick/temporary wizard setup (don't put your sim card in thought) and then pull the power plug from the router (and not the ac power plug that goes into the wall socket).
4. Wait 2 minutes with the router unplugged from power and then holding down the WPS button, power up the router.
5. Keep holding the WPS button for 10 to 30 seconds or until it reboots the router.
6. You'll know the WPS NVRAM erase was successful if the router boots up and the wizard greets you.
7. If the setup wizard does not come up, repeat from step 4 until it does.
8. Do another quick/temporary wizard setup and then flash the same (should be the latest) firmware again.
9. Do a final quick/temporary wizard setup and then follow immediately with a GUI reset to factory defaults (step 2) again.

At this point, the router should be in a good/known state.

When it boots up again, set it up while keeping the defaults alone. Do not put any customizations that are not needed to connect to your ISP. Do not use a backup config file.

With the router working reliably and stable like this for you, add your customizations one by one, rebooting and keeping notes between each change until you track down what is causing your specific issue.

Do not blindly put in old customizations either. The latest firmware may have better defaults and with the features, you depended on old customization to provide for you before.

 

[charsiufan]

Thanks. My router auto configured after I put in the SIM. No further configuration is required.

It is running off an APC UPS so the power should be stable.

The only issue is that the WAN status comes up as 'disconnected'. Switching off / on WAN or rebooting the device reconnects it.

Sometimes it works seamlessly for a week. Sometimes it needs rebooting 4 times in 2 hours..... Very strange.

 

[L&LD]

Thanks. My router auto configured after I put in the SIM. No further configuration is required.

It is running off an APC UPS so the power should be stable.

The only issue is that the WAN status comes up as 'disconnected'. Switching off / on WAN or rebooting the device reconnects it.

Sometimes it works seamlessly for a week. Sometimes it needs rebooting 4 times in 2 hours..... Very strange.

If you did get your router to a good/known state, then I would be trying a brand new SIM card from your ISP.

 

[ColinTaylor]

Given that you've tried multiple 4G routers from two completely different manufacturers I'm inclined to agree with you that this has nothing to do with the routers as such. So no amount of resetting will help.

So if it's not the router, and the cell company claims there are no problems with the tower I'd start by looking at external environmental factors. What is the 4G signal strength like? Are there any nearby sources of RF interference, like generators, electric motors, etc.

Of course none of that should stop the router reconnecting in the event of a lost signal, unless there was an issue at the cell company's end. My first suggestion would be to try a replacement SIM card, but you've done that. Have you tried a SIM card from a different cell company?

 

[charsiufan]

If you did get your router to a good/known state, then I would be trying a brand new SIM card from your ISP.

Yes, I've tried multiple sims with Jo improvement. And tried the sims in my phune and they work without issue.

Hence the question, what could cause the WiFi box to "choke" from time to time?

 

[Smokindog]

From the ASUS site it appears the outer two antenna are for the LTE radio in your router. Placement and position may be everything for your problem. I'm in a "fringe area" for all the big carriers and reception can change dramatically by simply taking a step in any direction when in the house. I have had to run micro-cell hotspots in my house, regardless of carrier, and/or use wifi calling. Given you're trying to use LTE for your WAN that obviously isn't an option

Who's your carrier and what bands/frequencies are being used from the tower(s) near you? Since you say your cell phone can use the same SIM I'll make the leap it's the same carrier (but not necessarily identical to what bands/frequencies it can use). There are tools such as LTE Discovery for android that can help you to identify this information and trouble shoot your connection.

You may need to relocate your router and/or upgrade the antenna and/or get a signal boost product. It all depends on your location, the local towers (bands/frequencies) and the ASUS radio (see below). Have you checked the coverage map for your carrier? It's possible your cell phone radio has access to channels the ASUS radio does not. This is a common occurrence, especially more recently. I can't tell you how many friends have said "carrier XYZ" sucks only to find they're using a phone that just can't receive what the new tower near them is offering

I did NOT spend a lot of time reviewing this or any other data, I was just calling out potential issues so don't take this as an exhaustive "analysis", just a list of "things to think about". Since you didn't give a lot of information about your location, carrier, nor cell phone make/model it's too difficult but there does seem to be some significant gaps in the ASUS radio coverage (meaning the intermittent coverage may be non-optimal and coming for a tower much further away than what your cell phone connects to). If you find this to be the case and IF this router can support an external device you can usually pick up a current standalone radio for most major carriers. I used to carry one from a carrier different than my phone when I traveled a lot for business. Again, just talking out loud here.

From the ASUS website (https://www.asus.com/Networking/4G-AC68U/specifications/)

LTE: Downlink 300 Mbps / Uplink 50 Mbps
HSPA+: Downlink 42.2 Mbps / Uplink 5.76 Mbps
4G FDD-LTE: 800 /1800 /2100 /2600
4G TDD-LTE: 2600
3G UMTS: 900 /2100​

https://www.whistleout.com/CellPhones/Guides/cell-phone-networks-and-frequencies-explained
https://www.signalbooster.com/pages...quencies-of-cell-phone-carriers-in-usa-canada

 

[charsiufan]

Thank you Smokindog - this is REALLY helpful and appreciate the full response. I'm guessing you are in the US, which I am not, so don't think my carrier being CSL will be of much help!

I'm using a Samsung Galaxy 8+ handset.

I did try 2 external aerials but I susquently learnt that their cable was too long at 10 meters. They didn't have any noticable effect on the 4G signal.

The Asus box is showing 50% signal strenght. I'm getting around 50 - 60 mb/s download and 5 mb/s upload speeds which seem quire good. Going to check out those links you sent me and try the app you recommended.

What do you mean by 'pick up a current standalone radio for most major carriers'?

Thanks again for your feedback.

 

[Smokindog]

Search for 4G hotspot. I don't know if you can use one with this particular router. You'll have to review the manual.

https://www.snbforums.com/threads/how-to-use-3g-4g-usb-modem-on-asus-router.30833/

Looks like the frequencies should be OK but again, things change fast these days and the devil is in the details.
https://en.wikipedia.org/wiki/CSL_Mobile

PS - I have an S8+ as well. Obviously a US version.

Thank you Smokindog - this is REALLY helpful and appreciate the full response. I'm guessing you are in the US, which I am not, so don't think my carrier being CSL will be of much help!

I'm using a Samsung Galaxy 8+ handset.

I did try 2 external aerials but I susquently learnt that their cable was too long at 10 meters. They didn't have any noticable effect on the 4G signal.

The Asus box is showing 50% signal strenght. I'm getting around 50 - 60 mb/s download and 5 mb/s upload speeds which seem quire good. Going to check out those links you sent me and try the app you recommended.

What do you mean by 'pick up a current standalone radio for most major carriers'?

Thanks again for your feedback.

 

[charsiufan]

Hi Smokindog

Why do I need a 4G Hotspot? I could borrow one from work but how does that leave me better off? Isn't that the function of the Asus router?

Sorry if I'm missing the point.

Search for 4G hotspot. I don't know if you can use one with this particular router. You'll have to review the manual.

https://www.snbforums.com/threads/how-to-use-3g-4g-usb-modem-on-asus-router.30833/

Looks like the frequencies should be OK but again, things change fast these days and the devil is in the details.
https://en.wikipedia.org/wiki/CSL_Mobile

PS - I have an S8+ as well. Obviously a US version.

 

[Smokindog]

Hi Smokindog

Why do I need a 4G Hotspot? I could borrow one from work but how does that leave me better off? Isn't that the function of the Asus router?

Sorry if I'm missing the point.

That was when I was pointing out the possibility of a significant router radio to frequency mismatch. You could basically buy another radio to replace the one built in. I don't think you've got that mismatch once you told me your location and carrier but again, only you can determine that.

 

[Burnsy]

charsiufan - Not sure if it is a coincidence but I am experiencing the same symptoms you described. I am too a CSL customer... Have you any developments in this issue?