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dinth's avatar
dinth
Dialled in
5 years ago

UDP issues on SuperHub3 - collective thread

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/page/15 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. 

 

Microsoft Teams
superhub3
torrent
UDP
voip
vpn

192 Replies

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  • fordy's avatar
    fordy
    On our wavelength
    5 years ago

    Hello!

    Thanks so much for this thread!  I thought i was going mildly crazy before I found it!  I've been encountering very similar issues resulting in Skype apparently overloading the Superhub and stopping it processing all traffic for 1-2 minutes, resulting in a brief internet outage.  Very frustrating after initially being super excited about Virgin Media rolling out faster broadband in our area, then discovering that actually my previous fibre service appeared far more reliable.  (Uno, Plusnet never had these issues).

    I couldn't replicate the exact symptoms that caused Skype to do this, but while investigating this one thing I did find I could replicate 100% of the time is making the superhub become unresponsive at 192.168.100.1, and 192.168.0.1 (Running in modem only mode) by sending many DNS requests.

    To replicate:

    • Open a terminal window and ping the superhub, ping 192.168.100.1 (keep it open!)
    • Launch a loop of constant DNS requests, in unix:  while ( true ) do host www.google.co.uk 1.1.1.1; done
    • Boom - the first terminal window will stop responding to ICMP pings within a few seconds.

    Note: Thanks & Apologies to Cloudflare for the DNS spam during my testing (owners of 1.1.1.1) but I think you can take it! 😉

    Make sure you cancel the loop of DNS requests - your modem will recover but most of the time not immediately, it seems to take it a good while to 'get over' having a high number of UDP packets thrown through it.  During this time the modem management page will be intermittent or unavailable.

    I managed to escalate this to VM, and one of their clever folks has replicated this in the lab, and so will log it with the Superhub vendor.  It appears to affect Superhub3 and Superhub 4 (I've tried both).  VM are sending me a Superhub 2 AC, so I'm hopeful I'll then get stable connectivity for a while until a new firmware is released!

    I'm hoping this issue, and the poor UDP handling issue / Skype dropouts are linked, and so both get fixed! 🙂

    • Topbloke's avatar
      Topbloke
      Up to speed
      5 years ago
      Thanks fordy you have nailed the exact issue I have and every Virgin customer for that matter.

      Your test is much better and technical though, I got the same exact issue using multiple torrents, it simply causes the hub 3.0 to have a mild heart attack, after a few minutes the blockage clears up and it goes back on as normal.

      During this time the internet is unusable and the hub 3 is not accessible, my gut tells me its still the puma faulty chipset in the modem since it sounds very similar only one other guy on reddit mentioned he had the same issue but mac cloned his hub 3 to a 3rd party Cable router and fixed the udp issue.

      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.

      I do not know how you got the Superhub 2 AC, I asked several members of Virgin Media staff and got the same answer from management, help desk, customer services, as in the item does not exist. Clearly it does still exist since you confirmed it !

      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?


      • dinth's avatar
        dinth
        Dialled in
        5 years ago

        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

    • dinth's avatar
      dinth
      Dialled in
      5 years ago

      Thanks @fordy for taking an effort to investigate this and persistence in trying to get to VM technical dept

  • dinth's avatar
    dinth
    Dialled in
    5 years ago

    Just an update, as VM has closed my complaint.

    As for the resolution, I've been asked to reset my modem and got a promise that they going to send me a wifi booster. Obviously, this only made me more frustrated, as it shows a complete lack of understanding technical terms or even their own systems - in my original complaint, I have explained that the issue occurs (at least in my setup) when the SH3 is in modem mode. Feels like they are processing complaints by sending out wifi boosters without even reading the content. 

     

    • Topbloke's avatar
      Topbloke
      Up to speed
      5 years ago
      Dinth:

      Have you tried mulvad in Wireguard mode and with a UK server ?

      I found my 20Mb to 1Mb latency/UDP glitch was improved using WireGuard protocol instead of the normal VPNs Openvpn protocol so now hit 20Mb fine in torrents with issues. You can switch it within the mulvad settings you may have to try 4-5 UK servers to find the fastest one.

      This was the only thing that really improved the UDP Virgin media issue for myself, not that I recommend WireGuard since it's not as good as openvpn.

      Its also possible the hub or wiring can be at fault (I went through 3 hubs) before getting a good one, torrents trigger my 1Mb cap but it's so random. If you cue up 30-50 torrents the more active downloads
      the more it triggers the issue even if TCP is the protocol on your torrent app.

      Openvpn TCP mode fixes the issue but it gave me a 50-70% speed loss, but then again UDP is the fastest mode. TCP has error handling so avoids these issues.

      In the end I just ditched torrents and went Cloud Services or you can try Newsgroups.

      pfsense logs should show bad packet error id messages when you hit the UDP glitch, sometimes it wiggles out of it and cures itself and the errors vanish, speed then climbs back to full when torrenting and with openvpn vpn use, I think its almost like the hub is choking on its own UDP packets.

      Only WireGuard protocol on vpn seemed to fix it for some people, 1 un-offical post on reddit suggested they cloned their mac modem to a 3rd party router and this fixed the udp glitch for them but it was not easy to do and may not even work any more.

      Other conspiracy theories out there are pumagate was never fixed and VM engineers simply made a firmware fix which worked around the issue but not actually fixing the issue properly so UDP glitches will always exist.

      Others left VM and went back to BT or other Fibre optic services.
      • dinth's avatar
        dinth
        Dialled in
        5 years ago

        Hi @Topbloke and thanks for your post.

        I have switched my Mullvad to TCP only and indeed it improved things a lot *WHEN* i'm using Mullvad. Unfortunately i dont have an option to switch to TCP only with my works VPN nor Teams for example. Actually, i could do my work from home forever, but now im forced to commute to the office for 2 hours one way every day because my 350Mbps (and unlike some regions, i do get stable 350Mbps to my house) VM connection is not able to handle a simple MS Teams videoconference. 

        What is interesting though, is where the "cap" comes from? For me it caps between 200-300 and 5kbps on two different modems i have tried, but other people report that it caps at 1Mbps for them 

  • archercj's avatar
    archercj
    Fibre optic
    5 years ago

    We are experiencing minor Teams issues (i.e. momentarily freezing).

    My setup isn't standard. I recently was upgraded to Gig1 (or whatever it's called). That comes with a Hub 4. With my Hub 3 setup I had it in Modem mode and my main router was a Linksys WRT32x with OpenWRT firmware. Anyway I thought I'd give the Hub 4 a chance. That lasted 2 days and I put it in to Modem mode and brought my Linksys back out.

    I was also given a set of Virgin wifi extenders.

    Setup is now a Linksys WRT32x flashed with the latest OpenWRT as my main router and the Virgin wifi extenders in operation.

    I have tweaked the channels to ensure they are out of range of other devices in the street. I have ensured that both the main hub and wifi extender are set with the same channels and frequencies. I also have my SSID's split between 2.4ghz and 5ghz with the same SSID set on hub and wifi extender. When I run something like NetSpot and move around the house I can see the device seamlessly moving between hub and extender depending on where I am in the house.

    But still Teams momentairly freezes,

    So I thank you for this thread. Will save me hours tinkering around if thye broblem is outside of my control.

    • jphobbs's avatar
      jphobbs
      Dialled in
      5 years ago

      Reading through this thread I think I may have a related issue. Here's my help thread: https://community.virginmedia.com/t5/Networking-and-WiFi/Router-constantly-dropping-several-times-an-hour/m-p/4487707/highlight/false#M346224

      Here's examples of my graphs:

      1. This has been going on for months

      2. SH3 (been replaced twice)

      3. Engineers have come twice in the last month and added an attenuator, replaced everything except the coax (which is newish) and the cable between cabinet and property.

      4. The on thing that confuses me is that we don't use modem mode, just normal router mode

      5. However, the thing that makes me think it's the UDP issue is that when I shut down my torrent client for 24 hours I got this:

      Which isn't amazing but it a level of service I would have killed for!

      Does this seem like a similar issue? I'm not getting slowdowns to 10 Mbps like others and I'm not using modem mode like others but when UDP services are running it does seem to kill the connection completely.

      The other thing that really confuses me is that we are not in any way heavy torrent users. No auto-snatching, no constant seeding/leeching. Like I said, just a handful of files a week absolute max which are left seeding for 48-72 hours at low speeds.

      Any help greatly appreciated!

      • fordy's avatar
        fordy
        On our wavelength
        5 years ago

        Can't see the images yet - but certainly looks like the same issue.  Issue looks to be present in router mode, just less so.

         

        Bear in mind in modem only mode I only need to send 15-25 or UDP DNS packets in quick succession to trigger a problem.  Torrenting by nature of being a download comes with far heavier load than a few DNS queries. 🙂

        Try pinging your modem's private IP on your network to see if you lose comms with your modem across the local LAN when connectivity goes.

  • MikeRobbo's avatar
    MikeRobbo
    Alessandro Volta
    5 years ago

    Will these UDP issues happen if the Hub is in Modem Mode with a third party router is used ?

    • dinth's avatar
      dinth
      Dialled in
      5 years ago
      MikeRobbo wrote:

      Will these UDP issues happen if the Hub is in Modem Mode with a third party router is used ?

      Yes, actually many people reporting it in the orginal thread were saying that switch Modem Mode OFF slightly improves the situation. 

      I havent tried that yet, as my network is quite complex. But in the past i have tried different firewalls/routers (Pfsense, OPNsense, Untangle) to check if it's not a router what's causing the issue and it's not. 

      MikeRobbo wrote:

      Does this page explain the >> FIX << using the Hub 3 ?

       

      No, with port forwarding/triggering, TCP connections are still forwarded through TCP and UDP connections are still forwarded to UDP.

      I can only think about two possible fixes:

      1. Stop or limit using apps/services using UDP connections - obviously that's rarely possible unless someone is just using computer for webbrowsing (i think that even Youtube partially started using UDP for high def/live content)  

      2. Set up a VPN account on a public VPN server which supports TCP-only tunnels (Mullvad for example), change VPN settings to TCP only and route all your network traffic (or just UDP traffic if you can set up such routing) through that TCP-only VPN tunnel. 

      • dinth's avatar
        dinth
        Dialled in
        5 years ago

        Today, I have spend a day testing my network connection with constant 5Mbps transfer over TCP and without any significant UDP traffic (except of ping) and havent had a single hickup of latency