Sky FTTP - Packet Loss/Internet Outage when Downloading via VPN

[andy.16v]

Hi, I am having issues with my Sky FTTP 500 connection which I am running out of patience with. I've exhausted all options I can think of, and I am led to believe this is an issue with Sky somewhere along the line, whether it's traffic shaping or some kind of fault somewhere, I have no idea but it's getting frustrating.

Firstly I should mention that while I am using pfSense as my router, all the following problems can be reproduced identically with the Sky Hub. pfSense is set up with IPv6-PD for the WAN connection. The problems exist on all devices, ethernet or Wifi. Another point to note is that I have disabled the Broadband Shield

The main issue I am having is with VPN usage. I have NordVPN connected in pfSense which my download clients route through. The problem occurs when downloading larger files, once they hit around 30GB, I start getting packet loss and the download speed drops until the point where the VPN loses connection, wont reconnect and I lose most internet connectivity outside of the VPN, it appears to knock out the DNS when this happens, but there doesn't appear to be a real pattern to what will and wont work. For example when it's not working properly, I get DNS errors on some websites, some sites I already had open still work (I assume due to cached DNS), and services like Discord generally carry on working. A ping test example below:

It usually takes a good 30 minutes after this has happened before everything returns to normal. I have tried many many things to try and cure this. A simple reboot of the router or ONT doesn't bring internet back either, it's almost like something externally has to reset to allow it to work. Weirdly, if I pause the download just as the speed starts to drop and the packet loss starts, the connection recovers and carries on working.

So far I have tried the following with no change in outcome:

• Changed VPN providers (Private Internet Access & NordVPN, also set up my own VPN using a VPS). 
• Changed VPN software (OpenVPN & Wireguard in pfSense, as well as the VPN providers' own software in Windows).
• Tried different DNS servers (Sky's own, Google, Cloudflare)
• As mentioned before, tried the Sky Hub with the same results, but have also tried a fresh install of pfSense and OPNsense.
• Tried IPv6 both enabled and disabled on the LAN.
• Tried both DNS of TLS and DNS over HTTPS.
• Left all equipment off for over an hour to get a new IP lease.
• Limiting VPN download speeds to less than half the connection speed.

The only other thing to add is that downloading the same file without the VPN, it downloads without a hitch at full speed. Otherwise the VPN stays connected 24/7 with little problems unless downloading. 

I have had some other oddities like packet loss while uploading my backups to Onedrive overnight as pictured below. The large packet loss overnight is from uploading to Onedrive. The smaller but complete packet loss tonight is after downloading via VPN and losing connectivity.

Hopefully that made sense, any pointers would be hugely appreciated as it's becoming a massive annoyance at this point.

[c33nf0]

Key @andy.16v 

Did you ever find a fix to your issue ?

Ive just found your post when trying to find some solutions as im having the same issue.

[andy.16v]

Sadly not really no. Just limiting my use of a VPN. But I still have weird issues.

At this point just going to live with it until my contract expires and move on to another provider. 

[Slipknot1]

I have ran into this issue as well.

I'm on sky's 900Mb FTTP and running into the same issue when using SSL connections and large downloads.

Takes 20/25 mins for the downloads to start again and get issues accessing some website

Also using IPv6-PD to connect to sky

[andy.16v · Accepted solution]

It is a strange one. I never managed to understand why it was happening, or why it wasn't affecting more people. 

But now I do know for sure it is a Sky issue. Last week I switched ISP, and ever since I have had absolutely no issues whatsoever, still running the exact same hardware/software config. I've used over 2TB in total over the past week, being able to download at full speed via VPN/SSL for hours no issue at all.

It got to the point where I cut short my Sky contract as it was so frustrating having no internet for 10-15 minutes every time something downloaded and suddendly the issue cropped up.

At least now I know for sure it is a Sky problem and not my setup. 

[Slipknot1]

Well I managed to get out of sky broadband after a price rise and using the 30 days noticed to be allowed to leave.

Once the sky FTTP finished joined Aquiss yesterday who did a port reclaim (They are very good and have real customer service/technical people who you can talk to!)

Straight on there 1Gb service and all my issues have disappeared so shows it's 100% a sky BB issue and nothing else

[Michelle1V]

Congrats on your good news, I've come here to post a similar issue myself, quite a lot of packlet loss the last few weeks, but im on FTTC 70mb. Never really had any issues until recently, but internal pings are all constant, but external pings seeing regular dropped packets.

Judging by the lack of support above, its probably not worth me posting anything here 😞

[jaybee7]

Similar / same issue here, 500mbps FTTp, when downloading large files the connection will randomly drop steadily to zero in the client. A Fast.com speed test still works but other websites time out.  Unplugging the ONT and router an waiting a few minutes sometimes sorts it, otherwise I have to wait 15 minutes or so for it to start working again.

I can usually avoid it by limiting the download speed in the Usenet client to 80% and only downloading large files one at a time (rather than queuing up multiple large files -small files aren't a problem) but this defeats the purpose of having the  fast internet! Very large files download on Xbox at full speed and never cause this connection dropoff, only on my PC.

I'm out of contract now due to the price hike, so if this is a Sky issue I can look into other providers. Aquiss sound interesting, thanks, I'm a bit wary of small providers though after getting messed around by a few during the early ADSL days!

[c33nf0]

I forgot about this thread

Im still having the same drop out when connection is maxed that vei had since day one.

Its a strange issue , as someone said it can be fixed by limiting DL speed but that shouldnt need to happen.

I might contact Sky tomorrow to see if i can leave contract due to price rise.

[Slipknot1]

Aquiss have been around a long time.

Been amazing so far and soooo refreshing to be able to talk to knowledgeable people with any technical questions.

[radiomike]

I stumbled across this thread having experienced this issue since I moved from BT to Sky last August. The connection on my 900Mb FTTP line always drops if I attempt to dowload anything above 30GB and takes around 30 minutes to recover.

Until I read the comments here I just assumed that it was something I'd have to live with till the end of my contract. I hadn't realised that I could cancel once I'd received the email about the price increase. So I called this morning to do so and it was a painless procedure thanks to a very helpful CS person.

I assume it's some sort of FUP policy that kicks in despite supposedly being an unlimited service.

So I'm going back to BT where I was completely satisfied with the service for the previous 2 years. So glad I saw this thread and the helpful comments from everyone here 🙂