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.

[EDIflyer]

Did anyone else have major issues last night? I found from about midnight until 9am my internet was completely down unless I used a VPN.  Phone showing an exclamation mark over wifi and 'offline' in Chrome, PC wouldn't connect to any site. However once VPN activated then all working OK - it was like a more extreme version of this issue!

[Nameless]

Thank you for mentioning this

My internet has become somewhat more unstable in the last few days however, apart from when I have been doing tests, my main indicator is that the Amazon Fire TV has been stuttering a lot over the last few days but this has been far more noticeable on higher resolution streams (FHD+) and for content that uses a high frame rate

[JonathanB]

Hi @EDIflyer,

I've had a check and we don't have any major widespread incidents reported, so it might have been more local of an issue. Glad to hear it was relatively short term and seems to have been fixed this morning.

Were the browser errors matching the usual "end of file" or "connection closed"?

Thanks,
Jonathan

[EDIflyer]

Thanks for checking @JonathanB - I think you've got my details on file so would be interested in you saw anything reported locally (my mobile is on iD Mobile that use 3 and had similar issues).  It was actually worse than the usual EOF/connection closed - I actually couldn't browse any sites at all but weirdly could still connect to my VPN and then everything worked fine. I suppose I was just wondering if it was a bigger version of this issue but may of course have been totally unrelated!

[Nameless]

A check-in for the new year with no changes

Hopefully this will be the year when these internet issues are put to rest for good

Although I am still busy at this time, I will try my best to continue making weekly updates

If any of you have encountered any changes, please let us know

[JonathanB]

Hi Everyone,

Sorry for the delay since the last update. We're still investigating the issue and have gathered some live trace data which is being analysed for more insight. We're also arranging some more internal testing. we haven't been able to reproduce the issue on our side in the past but we're hoping that the info gathered more recently will help us do so. Hopefully we'll have more to share about this soon.

Thanks,
Jonathan

[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.