UDP issues on SuperHub3 - collective thread

[dinth]

Hi. I decided to open a collective thread for UDP issues on SuperHub3, as it seems that many users are pestered by them, the impact is high and Virgin Media is not aware or fails to acknowledge the issue so far (they've been trying to fix my issues for a past year and nobody ever suggested that this has anything to do with UDP packets, until i found whats exactly the issue on my own).

This is the main thread for those issues was this one: https://community.virginmedia.com/t5/Speed/My-350Mb-connection-is-throttled-to-10Mb/td-p/3953746/pag... but it was originally created over a year ago and has a slightly misleading title. 

What we know so far:

1. The issue only occurs on SuperHub3 (and reportedly on SuperHub4) modem. SuperHub2 users are not affected. 

2. The issue occurs if an app/service is using an UDP connection to the internet. Examples of such apps: BBC Iplayer app, most online games, Microsoft Teams, Skype, third party VoIP apps, all kinds of VPN apps, torrent download apps. 

3. All UDP connections are performing very badly on Superhub3 modem, but also whenever there's a significant UDP traffic passing through the modem, other, non-UDP internet connections are slowed down to crawling speeds.

4. Depending on an user, the reported slowdowns are to between 10Mbps and 2kbps (!) speed measured through Speedtest. At the same time ping times go up all the way to 2000+ ms and huge packet losses (sometimes over 40%) occur. In other words, even web browsing is not possible if there's a significant UDP traffic going on through modem. 

5. VM street level fixes do not fix the problem - i had a whole uplink cable between CATV manhole and Virgin Media cabinet replaced by VM and it has not fixed the issue.

6. Replacing a modem does not fix the problem either - replacement SuperHub3 modems also have same issue.

7. Here's how the issue looks like on ThinkBroadband/Speedtest with just 1Mbps of UDP traffic flowing through the modem:

It's really sad, that Virgin Media fails to acknowledge this problem, as hundreds, if not thousands of people may be severly affected by it. The advice VM is giving out to the users is unhelpful and sometimes harmful (I've been told i need to chase the walls in the newly refurbrished house to replace my VM cable and desperate to fix the problem I have done that). Just look how many threads are being open on this forum describing similar issues with apps using UDP connections. 

[Topbloke]

https://www.ispreview.co.uk/index.php/2020/10/virgin-media-uk-offering-free-upgrades-to-hub-4-router...

"At the time the wider, albeit still very limited, distribution seemed designed to benefit areas suffering from weak WiFi or high utilisations (i.e. where local lines are being heavily used). The HUB 4.0 can bond 32 channels together, while the HUB 3.0 can only do 24 (i.e. the new router can be harnessed by those on slower packages to deliver an improvement, provided the operator supports the bonding change in those locations)"

Interesting since I am in a high utilisation area, maybe the hub 4 may help improve my issue, I would be happy to try this if a Virgin media staff can assist in this free hub4 router upgrade, if it is I can test if the UDP packet loss issue is still there, at least then others have a potential solution to this issue.

[jgtimperley]

Any update @fordy? Superhub 3 here on 200Mb. Long time modem-mode user but had to switch to router mode to reduce MS Teams/Zoom etc glitching during calls. I'd like to go back to modem mode really, but am unable until this issue is fixed. From my point of view, things were mostly fine at the start of the year (albeit with the occasional glitch), but started to get noticeably worse when my hub got the 9.1.1912.302 update, which was around the start of October. Not sure the issue is fully fixed in router mode, but it definitely seems better, and Teams/Zoom etc are actually usable.

Just for info, recreated with different routers, all tested using wired Ethernet, speedtests show the full 220/21, power levels well within spec on both upstream (4 channels at QAM64) and downstream (24 channels), BQM good and showing no packet loss etc. Switching to my 20Mb down, 3Mb up 'backup' line fixes the issue immediately for both me and my wife, so that also rules out computer issues. 

A possibly related issue is documented here.

[fordy]

Short story, three possible fixes:

1. Downgrade your SuperHub 3 or SuperHub 4 to a SuperHub 2.
2. Wait for a firmware fix from VM / Modem Vendor.
3. Alleviate the issues by running in router mode. (But I am really against this!).

Longer story for those interested: (Grab a cuppa!)

Yesterday morning VM visited and tried to replace my Superhub 4 with a new... Superhub 3 - argh! super frustrating as I had tried 2 different SuperHub 3's already through previous engineer visits and we had agreed the week before that they had a Superhub 2 to send me.  Eventually the misunderstanding was untangled and a different engineer turned up with a SuperHub 2.  He really didn't believe the Superhub 2 would improve this issue as its technically inferior, and tried to understand the fault in more detail (Clever chap - I agree with him, it does sounds crazy to downgrade to older tech, with less network capability!).

The instinct from most folks at VM seems to be to look at speed problems, wifi, or VM network issues, but this isn't any of those and I can hit headline speeds no problems.  My problem was demonstrably within my house! - connectivity issue between the PC and the Modem(Hub) over Physical cable, not onward to the internet.

Back to the saga.. hey presto!  Within minutes while the engineer was watching i was able to demonstrate that I could no longer replicate the issue and he left us with a decent 200Mb broadband service that seems way more reliable- hurray!  The modem management user interface stays 100% available via Ping, and HTTP no matter how much UDP traffic I throw out :).

Skype & Teams calls today have also been stable with no dropouts, so not failed over to the backup ISP line.

Few replies:

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@Topbloke wrote:
...
But you are perhaps the first on the entire planet to even get Virgin to admit the problem exist and there is confirmation the hub 3 is faulty.

Maybe a router firmware may solve it or help it, but till it is torrents or anything with high UDP packets or high connections like skype and similar may get these drop-outs problems.
...
Do you have any direct email or way to contact this staff member at the VM technical dept, if you can pm I would be grateful?

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I'm hopeful a firmware upgrade will fix it otherwise its an awful waste of hardware out there!  I do wonder how many people have this problem / fault condition and don't realise.  Any households where multiple people do Skype or teams calls simultaneously are sure to I would imagine as it affects Superhub 3 and 4. 

As for who to talk to - to be honest I've spoken to so many individuals at VM about this issue now, there isn't one particular one.  The best way is keep on escalating and don't let the complaint slide or close as you know more can be done.  I don't think the technical people alone can help you without first escalating and a complaint being logged.  Even after I had a complaint logged I found it impossibly hard to talk to a human who didn't want to reboot my router or upgrade my service to a faster speed because "my bandwidth is too low for what i need to do".  I received a letter acknowledging but contained no human contact number on, which pointed me back to the same super-frustrating text-support service which just sent me in loops burning my time.

Key I guess is keep on, follow the process, and just escalate if you don't get an appropriate response.

In the end we looked up the exec team to email the CEO & Deputy and explained our complaint in human words on the impact rather than my geek speak (ok the wife did, she's cleverer with words than I am!) (https://www.virginmedia.com/corporate/about-us/management-team), Severina responded in minutes and we had a call back from someone the next day who was able to progress things.  They are not technical though and details do get lost in translation between the engineers that visit, so be prepared to re-explain your problem a few times (I found it calming to have an A4 printed crib-sheet defining my problem!).

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@dinth wrote:

Also fordy would you be able to share the ticket/reference number of your issue with VM. I'm trying to explain VM customer service that my issue has nothing to do with weak wifi signal and being able to reference your ticket would be super helpful

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Unfortunately they wouldn't give me a ticket reference number, I have my complaint reference number but I'm told that is unique to me and tied to my complaint only.  I tried to ask for another ticket number for other customers to reference who have the same issue but were told they would have to log their own complaint reference number. 😞

I feel your pain as I had to explain so many times that it drove me somewhat crazy, that it really isn't a wifi issue, wifi is totally unrelated as I run it in modem only mode, with a wire.  I was asked to reboot my hub so many times that i eventually said I refuse to reboot it, as it won't change anything and just causes me an unbelievable additional 10 minutes downtime per reboot!  I'm sure the person asking me to reboot it was keen and eager to help, but their previous 5 colleagues had all done exactly the same! 🙂

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@Topbloke wrote:

https://www.ispreview.co.uk/index.php/2020/10/virgin-media-uk-offering-free-upgrades-to-hub-4-router...

Interesting since I am in a high utilisation area, maybe the hub 4 may help improve my issue, I would be happy to try this if a Virgin media staff can assist in this free hub4 router upgrade, if it is I can test if the UDP packet loss issue is still there, at least then others have a potential solution to this issue.

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Sadly I don't think a SuperHub 4 will fix the issue, as high utilisation area is unrelated.  This particular issue seems to affect superhub 3 and superhub 4 modems running in modem only mode in exactly the same way :(.  Your only option right now is a downgrade, or wait for a firmware fix.

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@jgtimperley wrote:

Any update @fordy? Superhub 3 here on 200Mb. Long time modem-mode user but had to switch to router mode to reduce MS Teams/Zoom etc glitching during calls. I'd like to go back to modem mode really, but am unable until this issue is fixed. From my point of view, things were mostly fine at the start of the year (albeit with the occasional glitch), but started to get noticeably worse when my hub got the 9.1.1912.302 update, which was around the start of October. Not sure the issue is fully fixed in router mode, but it definitely seems better, and Teams/Zoom etc are actually usable.

Just for info, recreated with different routers, all tested using wired Ethernet, speedtests show the full 220/21, power levels well within spec on both upstream (4 channels at QAM64) and downstream (24 channels), BQM good and showing no packet loss etc. Switching to my 20Mb down, 3Mb up 'backup' line fixes the issue immediately for both me and my wife, so that also rules out computer issues. 

A possibly related issue is documented here.

---

Good spot - looks almost certainly related and exactly what i experienced.  I don't think I was a customer during that previously firmware version though. 🙂

[jgtimperley]

Thank you for the update, although it's not too promising for those stuck with the Hub 3. As things seem OK in router mode for me, I think I'll wait it out - as you say, hopefully a firmware update will alleviate the issue, but let's face it, the grossly underpowered Puma chipset in the Hub 3/4 is always going to cause problems.

Glad to hear you've got your issue sorted though.

Edit to add: I am genuinely pleased for you, even if my closing line doesn't appear sincere!

[Topbloke]

thanks fordy for the detailed reply, its fine any update or info is something right now.

This issue has been going on for 3+ years sadly, there is the other gigantic thread which acknowledges the UDP fault within faulty hub 3 from a few years back.

It is sad that Virgin Media sent a letter to you but used their 'get out of jail free card' and left no name or department, I don't think Virgin Media can admit the hub3 is faulty.

Asking VM to downgrade to hub 2.0 is the only fix I agree and this is 100% not just a one off incident or unique customer issue, 100s of customers have described and mentioned the same udp fault for the past 3 years across multiple threads on this forum and ispreview, reddit etc.

Just to illustrate the issue a bit more....

https://www.ispreview.co.uk/index.php/2020/09/quick-update-for-virgin-media-speed-issues-on-ipv6-tun...

Posted 3 days ago;

Having spent a lot of time with a SH3 and trying to debug this and other behaviour it’s not just IP41, and there won’t be a fix. As above it’s the ‘normal’ puma 6 hardware bug unfortunately.

Anything non-TCP will cause this and worse effects, the latency spikes are a far worse aspect.

I went from a SH2 to a year of frustration with a SH3 before being ‘lucky’ enough to be able to change for a SH4 where all the previous issues evaporated. Smokeping graphs from before vs after are night and day.

They’re going to give it lip service and nothing more I’d imagine as it’s not really possible to fix per say and most of their customer base won’t know they’ve got a problem, outside of it pros/enthusiasts it’s the gamers it hits the hardest.

July 2019:

https://www.ispreview.co.uk/index.php/2019/07/a-look-at-virgin-media-uks-future-hub-4-gigabit-connec...

I wish they’d roll this hub out to everybody. The Intel Puma 6 bug hasn’t been fixed, because its a hardware based defect. All they did was simply mask it, via offloading the DNS requests to the wifi chip. You can still observe this issue (large latency jitter) on TCP/UDP connections.

---------------------------------

back from me :
Its possible you are correct and hub4 may not improve the udp fault but as you read a few comments from ispreview site reviews in the comments section, a few have said the hub4 is more powerful (spec and cpu wise) so its able to handle the udp packets better, possibly a long shot but it helps or fixes the udp issue.

Could explain why Virgin Media are suddenly giving out free Hub 4 routers like its Candy......

[jgtimperley]

Quick update on my situation. After running the Hub 3 in router mode for over a week, everything has been back to "normal". Teams/Zoom calls run much more smoothly. In fact, I'd say that web browsing on phones, tablets etc seems generally snappier, with less initial delay while the page loads. It's almost as though things have been slowly deteriorating with modem mode over the past few months/firmwares and we've just not noticed. I've done away with my own router and am just using the Hub 3 as my LAN gateway, as I don't want to risk any issues with double NAT (even with the DMZ set, double NAT still sucks). Wifi is, and always has been provided by a Ubiquiti wireless LAN setup with multiple wired APs, but work laptops use wired connections.

Background in case anyone stumbles across this. I'm on the 200Mb package, Hub 3, using modem mode for the last 3.5 years into a Mikrotik router. Everything running seemingly fine with two people working from home running VPNs, MS Teams/Zoom calls etc, plus normal streaming/browsing etc in the evenings, up until around the start of October, when Zoom/Teams calls starting experiencing freezing, lagging etc on both work laptops, which both use wired gigabit connections back to the Mikrotik. Speedtests always show 220/20 (even single-threaded most of the time, which is pretty impressive). Issues go away immediately by switching to the backup 20/3 Openreach FTTC connection.

Wanting to persevere with modem mode (after a few issues with router mode including VoIP phone not liking the HTTP intercept when the cable interface goes down and failing to re-register when it comes back up, Hub 3 not liking my Netgear switch), I tried a number of other routers (Fritzbox 7530 and Netgear D7000) to see if there was any improvement. Issue persisted with all three setups.

[dinth]

>In fact, I'd say that web browsing on phones, tablets etc seems generally snappier, with less initial delay while the page loads.

That sounds very plausible, DNS queries are also UDP. 

>After running the Hub 3 in router mode for over a week, everything has been back to "normal"

Unfortunately not in my case. Sure, router mode works 100x better, but it's only 100x better than "doesn't work at all" 🙂 What I'm saying is that I bet that someone at VM will at least think about dropping support for "modem mode" as to fix the issue, but that's not a viable fix or even workaround. Even in router mode SH3s are struggling with UDP, not as bad as in modem mode but still. Now I'm in router mode and still every single time i run heavy UDP traffic, I'm seeing some dropped packets. This cannot be related to the line quality if it only happens with UDP and to be honest, in times of door locks, burglar alarms or even smoke alarms all connected to the internet, a couple of dropped packets at the wrong time may cost the owner a lot 

[fordy]

Agree.  If support for modem mode was dropped; I’d seek to break contract and change ISP.  I’d hate to be forced to use a specific router.

[jgtimperley]

>Unfortunately not in my case. Sure, router mode works 100x better, but it's only 100x better than "doesn't work at all" 🙂 What I'm saying is that I bet that someone at VM will at least think about dropping support for "modem mode" as to fix the issue, but that's not a viable fix or even workaround. Even in router mode SH3s are struggling with UDP, not as bad as in modem mode but still.

All agreed. I've only ever had the Hub 3 (only got Virgin 4 years ago and this is my first experience with them). The backup Openreach FTTC is noticeably better in *every* aspect other than speed, and unfortunately 20Mbps down doesn't really cut it these days. If I could get 80Mbps, then I'd probably not even have the Virgin line, but at around 1km from the FTTC cab it's never going to be great.

Also agreed that router mode isn't a fix, and it would be great to have modem mode back again, but for the time being I'll just wait this one out and stay in router mode. For reference, I'm on firmware 9.1.1912.302, and connect back to a Cisco CMTS (cmts 16 in Baguley).

[dinth]

>I've only ever had the Hub 3 (only got Virgin 4 years ago and this is my first experience with them).

I used SH2 before i was also doing a lot of torrenting at that time and oh it was so responsive and just felt fast, even if technically I only had 100Mbps connection. Even with max bandwidth being 3 times slower, web browsing felt faster than on SH3 even in router mode.