Intermittent connection issues loading/changing site- secure connection failed/site can't be reached

[EDIflyer]

Is anyone else occasionally getting a 'connection down' error from Chrome (or 'Secure Connection Failed' from Firefox) when changing page - if I hit refresh it works fine. At first I wondered if it was the site I was using but have noticed it on multiple different major websites over the past couple of months and not noticed it from other locations where I don't use Three Broadband so does seem to be related to the router/connection (this is via wired Ethernet too, so not a WiFi problem).  I've tried changing DNS server in case that helps but no difference.

It mainly seems to happen when trying to first load a site or (annoyingly) at checkout when a different site is being loaded as part of the checkout process.  It certainly doesn't happen everytime but does happen with reasonable frequency.  I've also noticed I often get it when trying to pull/push from/to Github too and have to do so a number of times for it to work (browsing the Github website works fine).

I'm using a NR5103E with Firmware Version V1.00(ACBJ.0)b14 - I tried rebooting it but to no effect.

[Nameless]

Hello and thank you for your update

Just to make sure, if you and the other Three staff members have a different way of accessing the network infrastructure compared with your customers then that could be a reason why you do not seem to notice these issues

For your tests, please make sure that you and the team(s) at Three are using a setup that is identical to a customer's setup including, but not limited to:

• Router used, its firmware and its settings
• Same default APN settings
• PC/Mac/Linux computer/laptop with no extra software operating between the web browser and the operating system in regards to using the internet
• Android/Apple mobile device with no extra software operating between the web browser and the operating system in regards to using the internet

Although I usually test on a PC running various forms of Linux and its associated extras, I have seen errors on the following devices:

• Laptop running Windows 10 as new (Same error messages)
• Apple iPhone 11 Pro Max (Manifests as website connection errors)
• Nintendo Switch (Manifests as internet connection errors)
• Amazon Fire TV (Manifests as internet connection errors or website connection errors)

I always test the latter two devices with either a PC, laptop or the iPhone mentioned as they are unable to report the specific issue but are always momentarily affected whenever I hit the PR_END_OF_FILE_ERROR when testing extensively and have used all of these devices on two Three provided routers:

• ZTE MC801A (I think that is the correct model)
  
• Zyxel NR5103EV2

I would have tested on a Zyxel NR5103E but the SIM slot was broken...

Although it has been a very busy time, I will still continue to do my tests although I may be a bit delayed with my own updates at this time

[JonathanB]

Thanks for this insight @Nameless, so just to clarify the "PR_END_OF_FILE_ERROR" is specifically seen on a PC browser and with the other devices the issues coincide with when you're also seeing those browser errors? E.g. we're not actually returning end of file on Switch or Fire TV right?

[Nameless]

Hello and thank you for your response

Yes the PR_END_OF_FILE_ERROR can only be mentioned by PC like devices and usually from within a web browser however, some web browsers may hide some errors to give a generic "connection failed" message. For the other devices I have listed:

• The Apple iPhone 11 Pro Max will only mention website connection errors in a generic way even when a PR_END_OF_FILE_ERROR should have been observed. I have gone through the list of problem websites on the device and the usual PR_END_OF_FILE_ERROR pattern of "Fail once, work on a reload" occurs when there are problems. Streamed content suffers in a way similar to the Amazon Fire TV as mentioned below
  
  
• The Nintendo Switch will only mention internet connection errors. From within a game connected to the internet, this will cause the game to mention that there has been a connection error and it will act as if the internet connection has been severed. The Nintendo Switch may not be as generous with certain failures compared with other devices however its internal Wi-Fi card is working fine as I have taken it out for hours whilst connected to several different Wi-Fi networks (Including trains!) without similar issues
  
  • On a really bad day for constant PR_END_OF_FILE_ERRORs, games will fail to stay connected
  • If the console itself overrides the multiple failures (Rare), it will treat the network as if it has no signal regardless of how close it is to the router (Usually within 2m) but will not disconnect automatically
• The Amazon Fire TV will show either an internet connection error or website connection error dependent upon the app in use however, on some streamable content, this issue may manifest as a momentary stutter due to having a large enough buffer to mask the issue.
  • For streams with smaller buffers, either an internet connection error or website connection error is likely to occur within seconds of the stream pausing (If not immediately) due to running out of buffered content
  • For streams with larger buffers, dependent upon the app in use or stream reload timing, a delayed momentary stutter or, when errors are more frequent, significant stuttering is likely to be seen
  • Some apps will tolerate a certain amount of failures before crashing, stopping the stream or pausing indefinitely
  • The home menu usually becomes unresponsive to an extent but this is hard to test

Additionally, these device specific responses also happen on my testing PC and the laptop mentioned however, possibly also due to the applications I use, only the web browser (Mozilla Firefox is what I use) will mention the PR_END_OF_FILE_ERROR - Everything else will mention its generic error message which is usually a "connection error" type of message. These failure messages all happen together or within a few seconds with only the first sign of a stutter potentially being delayed by more seconds due to the buffer length although MPV player will mention a connection failure message in its logs at the exact time the browser will mention the PR_END_OF_FILE_ERROR

If these other devices were "smarter", they surely would mention the exact error - It is highly unlikely that there would be various different connection related issues simultaneously...

[EDIflyer]

Certainly in my experience what tends to happen on a smart TV is Netflix, Amazon Prime, etc. fails to load. It might start and have empty boxes that then don't get filled in. I normally have to manually kill the app and go back in, sometimes a few times. It would seem to be from the same closed HTTPS connection but without it being able to report the same thing.

[Nameless]

I also experience this kind of issue with the Amazon Fire TV

[x-c311]

Just as an update this is still ongoing for me since my local mast was "fixed". I have changed the bands as suggested and I would say it helps a little but there are still issues. I know this going to be difficult for others to test but it really affects my app for my ecovac robotic vacuum.  Pretty much every time it says offline then I have close the app are retry and it then works.
Daily reboots of the router also helps I think, it don't believe it's a router issue as I have tested 2 different models. Its more to do with long you have been connected to the mast. 

To do further testing I'm now running on 4G only just to see if I get the same issues.  My 4G is pretty good tbh, 250Mbps down, 36Mbps up.

[Nameless]

Thank you for your update and testing

I have just completed some testing and I can confirm that the issue is still there and random although mast connection duration is something I have not tested for before

The most I can say in regards to connection duration from my observations is that the usual connection errors do not seem to change in a noticeable way although, after months of testing by constantly changing things and resetting the router, I have been testing lately without resetting the router so I can test for X many days since restarting the router (44 days so far)

As far as I last checked, I did not see these issues on 4G alone however paying for a 5G service when restricted to 4G is not value for money and should at least be a discounted option that is available

I will do some more testing of 4G alone when I can

[x-c311]

I completely agree that using 4G is not an acceptable solution but I've got to the point where I'm so fed up of the constant errors and unknown of is this app broken or is my connection, that the reduced download speed is the better option.

The other day my daughter installed a new game of her handheld but she had played before so wanted to pull down her save game from the cloud. But the game kept reporting the servers where down so couldn't play. But where they actually down, who knows, unlikely, the next day I tried again on 4G and it worked fine.

Just fed up of it now

Sorry for errors on a mobile

[x-c311]

Hi all,

I've had this problem for the past year, and tried all sorts of things to fix, different DNS, APNs. Different SIMs using the three network, 2 different 5g routers. A reboot sometimes helps but only lasts a few hours before I see the same error creeping back.

Interestingly however my local mast is currently broken eNB ID 5548. I complained to Three a week ago about it as it gave 5G signal but no internet. In any case they now appear to have turned it off, while they fix it I assume!? Because now all my 5G three devices connect to eNB ID 4603 which is about twice the distance. I still get 5g but 1 bar. I get about 150mbps compared to 650mbps before. However 3 days now and no errors, no connection reset no SSL problems, nothing!

Therefore it would interesting to see what the difference is between the 2 masts, well was as its off now. I mean to be honest I'm hoping when they fix it, I hope I don't get these errors anymore! Just thought it might make an interesting comparison.   

[Nameless]

Hello and thank you for your post

If you have not done so already, please make a quick note of all of your settings including the router model and the band selection (If set to auto, please record which bands you are connected to at the time you check)

Do you have any websites which would normally cause the PR_END_OF_FILE_ERROR to appear? Even if it is a random occurrence, I would like to add them to my list for testing as I still have not found a website which will always fail however those websites in the list have been mentioned as failing at some point in this very long forum thread...

Also, can you please confirm that you are definitely connected to the 5G network? You should be connected to an N band (N78) as well as at least one B band. This is to rule out a highly performant 4G connection as I am led to believe that it can reach a speed of ~150Mbps