on 13-08-2021 12:00 PM
I have been having issues with my download speed with certain applications.
I recently had work carried out by Openreach, who replaced all of my internal wiring and the external wiring all the way to the green street cabinet. Since that was done, the line stability and upload speed issues I was having have been solved. For the most part, my internet connection now seems to be good.
However, I still have a couple of issues with download speed. I've been trying to troubleshoot this myself and am now completely out of ideas. I was hoping someone here might be able to help.
My download speed is mostly fine. My router is currently synced at 72.3 down, 20 up.
Running Google's speed test (reached by searching google for "speed test") gives a result of 62.2 down, 18.4 up, which is about what I would expect. Downloading from a games console also shows about this speed. Downloading a file on a PC looks OK too. So far, so good.
The first thing I have a problem with is speedtest.net. It does not seem to matter which server I select. Whether speedtest chooses the optimal server, or I select any number of others, my download speed is around 10-15 down (upload is ~20 however, and fine. Latency is also very low). This is true for the embedded speedtest that TalkTalk uses in my account / service centre too. I have tried using speedtest.net from multiple devices - multiple computers and phones, on wifi, and via ethernet directly into the router. I get the same slow download result on all devices, no matter which server is selected. All of the devices show more realistic / accurate download results if I switch to mobile data.
The second thing I have a problem with, which is more impactful, is slow downloads with the Cisco AnyConnect VPN I use for work. Again, upload seems to be fine. I can upload files to work servers at ~20Mb/s (~2MB/s). But I can only download in a range of 10-100KBps. It never gets higher than this. I also have a problem when trying to use git fetch or git pull, where the command always fails with an error "fetch-pack: unexpected disconnect while reading sideband packet". Through some googling, it seems this could be related to poor network performance.
If I switch to mobile tethering, I can download from work servers at around 1.5-2MBps, which is what my colleagues see on others ISPs. Git fetch works when tethering too. My partner works for the same company, and we both see the same results when using the TalkTalk network vs mobile tethering.
I recently requested a new router through this post (https://community.talktalk.co.uk/t5/Broadband/d-link-dsl-3782-with-Cisco-AnyConnect-VPN-issues/m-p/2...), as I had seen some other community members having issues with the DSL-3782 and Cisco AnyConnect. I've set up the new router (a Sagemcom FAST-5364-3), and allowed it to update to the latest firmware (SG4K10002816t), but this has not solved my VPN issue. There is no difference in download speed.
Before making that post, I had spoken to someone on TalkTalk live chat, who would not send a new router, but ran a line test and said there was an issue at the exchange that an engineer would have to look at. I spoke to that person on Thursday 5th August, but have not had any email or text updates about that engineer work, so I don't know if anything happened. However, if I run a line test from the my account page, it shows no issues.
I have tried making some changes to the settings on the new router to see if it solves my VPN issue. I have tried enabling port forwarding for the UDP ports the VPN uses, and the ports used by Gerrit. I have tried lowering the MTU value of the interface on my laptop. I have tried using Google's DNS servers. I have tried lowering the firewall setting to "low". And I have tried letting external IPs connect to my laptop through the router's DMZ settings. I have also tried disabling all of the options in Homesafe (virus / spam etc). None of these attempts have made any difference to download speed.
Does anyone have any ideas? I'm completely stuck now! What could possibly cause download speed to only be slow when using speedtest.net and through a VPN? Just to be clear - the issue with speedtest is while not connected to the VPN - so it is not just a VPN problem.
Can anyone see if engineer work was carried out after my live chat on 5th August? Can an issue still be seen at the exchange?
Thanks for reading, and for anything you may be able to suggest,
on 23-09-2021 08:43 AM
on 22-09-2021 03:55 PM
Yes we'll tell the engineer that it's a throughput speed issue rather than a sync speed issueI. If you'd like us to arrange the engineer visit can you confirm:
I've also sent you a PM to confirm some other details
on 22-09-2021 03:41 PM
Yes that would be good if you think that's required. My only concern is that if the engineer is looking for issues with sync speed then they won't find any problems - as the sync speed is always ok. Will they be able to test/investigate the actual throughput too?
Like I mentioned in the first post, I did have an openreach engineer replace all of the wiring in my property, the master socket, and wiring outside the property to the cabinet in a previous visit which fixed a separate stability issue.
on 22-09-2021 01:05 PM
OK thanks Jamie. To investigate further we'll need to arrange an engineer visit. if you'd like us to do this please let us know and I'll confirm some details with you
on 22-09-2021 12:48 PM
I've turned off all other devices so I can only see my personal laptop in the "my devices" list on the router (no VPN on my personal laptop).
I still see the same slow download throughput.
on 22-09-2021 11:43 AM
Thanks for running the tests. If you just have one device connected to the internet (not the VPN device) and all other devices switched off, do you still see the slow throughput?
on 22-09-2021 11:29 AM
Yes I see slow download consistently at all times of day. Upload speed is always fine. The network utility on OSX that the instructions suggest using is no longer supported. It suggests using the command line instead, which is what I've done. This is wired to the router.
PING google.co.uk (188.8.131.52): 56 data bytes
64 bytes from 184.108.40.206: icmp_seq=0 ttl=117 time=10.163 ms
64 bytes from 220.127.116.11: icmp_seq=1 ttl=117 time=9.905 ms
64 bytes from 18.104.22.168: icmp_seq=2 ttl=117 time=9.955 ms
64 bytes from 22.214.171.124: icmp_seq=3 ttl=117 time=10.041 ms
64 bytes from 126.96.36.199: icmp_seq=4 ttl=117 time=10.162 ms
64 bytes from 188.8.131.52: icmp_seq=5 ttl=117 time=10.338 ms
64 bytes from 184.108.40.206: icmp_seq=6 ttl=117 time=10.157 ms
64 bytes from 220.127.116.11: icmp_seq=7 ttl=117 time=10.073 ms
64 bytes from 18.104.22.168: icmp_seq=8 ttl=117 time=10.150 ms
64 bytes from 22.214.171.124: icmp_seq=9 ttl=117 time=9.817 ms
64 bytes from 126.96.36.199: icmp_seq=10 ttl=117 time=9.783 ms
64 bytes from 188.8.131.52: icmp_seq=11 ttl=117 time=10.342 ms
64 bytes from 184.108.40.206: icmp_seq=12 ttl=117 time=10.208 ms
64 bytes from 220.127.116.11: icmp_seq=13 ttl=117 time=9.505 ms
64 bytes from 18.104.22.168: icmp_seq=14 ttl=117 time=10.191 ms
64 bytes from 22.214.171.124: icmp_seq=15 ttl=117 time=10.485 ms
64 bytes from 126.96.36.199: icmp_seq=16 ttl=117 time=10.171 ms
64 bytes from 188.8.131.52: icmp_seq=17 ttl=117 time=10.317 ms
64 bytes from 184.108.40.206: icmp_seq=18 ttl=117 time=10.265 ms
64 bytes from 220.127.116.11: icmp_seq=19 ttl=117 time=10.147 ms
64 bytes from 18.104.22.168: icmp_seq=20 ttl=117 time=10.116 ms
64 bytes from 22.214.171.124: icmp_seq=21 ttl=117 time=10.215 ms
--- google.co.uk ping statistics ---
22 packets transmitted, 22 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 9.505/10.114/10.485/0.212 ms
I did see some packet loss when I left it running a bit longer
--- google.co.uk ping statistics ---
504 packets transmitted, 498 packets received, 1.2% packet loss
round-trip min/avg/max/stddev = 9.249/10.153/15.238/0.417 ms
traceroute to google.co.uk (126.96.36.199), 64 hops max, 52 byte packets
1 192.168.1.1 (192.168.1.1) 10.896 ms 0.623 ms 0.454 ms
2 ae50-ner001.msp.as13285.net (188.8.131.52) 4.522 ms 28.144 ms 7.759 ms
3 ae50-scr001-msp.as13285.net (184.108.40.206) 4.721 ms 15.835 ms 4.312 ms
4 ae63-scr102.thw.as13285.net (220.127.116.11) 10.177 ms 9.649 ms 9.513 ms
5 18.104.22.168 (22.214.171.124) 10.725 ms
126.96.36.199 (188.8.131.52) 10.035 ms
184.108.40.206 (220.127.116.11) 10.487 ms
6 * * 10.252.230.158 (10.252.230.158) 12.195 ms
7 18.104.22.168 (22.214.171.124) 11.315 ms
126.96.36.199 (188.8.131.52) 10.756 ms 10.112 ms
8 184.108.40.206 (220.127.116.11) 10.352 ms 10.288 ms 9.840 ms
9 lhr25s33-in-f3.1e100.net (18.104.22.168) 9.688 ms
22.214.171.124 (126.96.36.199) 12.714 ms
lhr25s33-in-f3.1e100.net (188.8.131.52) 9.912 ms
on 22-09-2021 08:55 AM
on 22-09-2021 08:53 AM
Yes, I had a troubleshooting session with my company IT department who did not find any issue.
Surely this must be an issue with TalkTalk's network and nothing to do with the VPN. The VPN being slow is just the most impactful part of this problem for me because it means I am unable to use my home internet connection for work.
Slow download over the VPN is just one thing I am seeing. I am only using a VPN on my company laptop, and not on other the devices that are seeing poor connection speeds. My home laptop, desktop and smartphone all see download speeds to any speedtest.net server of 4-8Mbps.
The fact that my router can download at expected speeds from large content delivery services like google, but has very slow download speeds when connecting to, presumably, less commonly used servers like the ones speedtest is using, or the servers that my corporate VPN uses must mean something? Does TalkTalk have a high bandwidth connection to popular services in my exchange but low bandwidth to the rest of the internet? I am not sure how to narrow down the problem any further. The speedtest that TalkTalk uses to fill in the "speed to my router" graph is also showing low download speeds again.
I also do no understand why the problem seemed to be resolved from the 6th September to 19th September, and has started again on Monday 20th.
on 22-09-2021 07:14 AM
on 21-09-2021 06:46 PM
I am seeing varying performance across different services.
The "speed to my router graph" on the talk talk service site has now updated and shows 70Mbps up until Sunday 19th, but yesterday the speed was recorded as 4Mbps.
The dl speed in the graph showed as anything from 4-8Mbps for a couple of months (I'm not sure exactly how long) prior to 6th September. Without me changing anything, all services downloaded at expected speeds from 6th September until 19th September and the graph showed ~70 each day.
Anything over my corporate VPN is now horribly slow again. Minutes to load webpages. scp from a work server maxes out at around 50KBps. The dashboard on the xbox that loads in elements from the internet is now taking a minute+ to complete loading. While download speeds were normal (6th - 19th) these would all load almost instantly and scp would download from the same server at 2MBps.
The network test on the xbox while wired is today showing a download speed of 30Mbps.
Any download test with a server on speedtest.net shows low download speeds of 4-10Mbps. The google speed test still shows a reasonable download speed of 55-60Mbps. Google content servers also seem to be OK, for example, looking at the stats while watching a video on youtube shows my connection speed as being anywhere from 30Mb to 50Mb. 4K video on Netflix seems to be fine too.
I tried turning the router off for 45 minutes again earlier and then switched back to my old D-link DSL-3782. That did not make any difference and still saw the same problem. So I turned that off, waited 45 minutes and plugged the Sagemcom fast5364 back in.
on 21-09-2021 07:39 AM
on 20-09-2021 05:02 PM
I've tested with multiple devices using both ethernet and wifi. The low download speeds are seen across all devices.
I do not think this is an issue with anything in my home setup.
I mentioned this in an earlier post when I previously saw these issues, but the speed I am receiving seems to depend on what I am connecting to.
For example, using the speed test built into google (which uses measurementlab.net) always gives the download speed I expect. It gave good download speeds previously when I had these problems, and today it shows ~55Mb/s. Netflix has also seemed to be OK although I haven't checked the DL speed it is getting today. (Note that this is true across multiple devices, wired or wifi. So it seems it is the external service I am connecting to that is the interesting factor.)
Testing with any server on speedtest.net however, I am currently seeing 7Mb/s. Other services are also showing slow download speeds again.
I'm not sure exactly what this means, but it seems like the download speed is poor when connecting to certain IP addresses.
on 20-09-2021 03:22 PM
on 20-09-2021 03:13 PM
I have just switched the router off for around 40 minutes and then back on again. The settings page shows it has synced at 74Mb down again, but I am still seeing the same low download speeds.
on 20-09-2021 11:49 AM
Line test is passing, last profile change was on the 7th. Could you switch your router off and leave it off for at least 30 minutes then switch back on and retest
on 20-09-2021 10:49 AM
I gave up on the idea of this ever being fixed. However, on Monday 6th September, having not changed anything in my setup, I noticed that my VPN download speed had increased to 2MB/s, which is what I'd expect based on the speeds I get using my mobile hotspot. Speedtest.net on non-vpn devices was now giving accurate speed results too. ~70Mb/s. I assumed that something must have changed in TalkTalk's network or the cabinet or exchange. Everything was working as expected!
However, this morning, having changed nothing about my setup, I'm back to 40KB/s VPN speeds and weird speedtest.net results on non-vpn devices of ~17Mb/s download. Upload still remains fine.
Any thoughts on what could have happened? I was really hoping this problem was now behind me! But here it is, back again. My router shows it's been connected for just over 13 days. speed-to-router results are only showing up to 15th September, but all showing 70Mb/s
on 16-08-2021 09:35 AM
on 15-08-2021 09:37 PM
Just a small update to say that I am again seeing slow download speeds to some devices, and when using speedtest.net.
The router has been connected since I restarted it Friday lunch time, and is currently showing:
Connected since 2d 07h38m52s
Looking at the speed to my router in my account, I see:
Sunday 8th - 59Mbps
Monday 9th - 67 Mbps
Tuesday 10th - 66 Mbps
Wednesday 11th - 66 Mbps
Thursday 12th - 8 Mbps
Friday 13th - 4 Mbps
Saturday 14th - 8 Mbps
Runing speedtest.net to 3 different servers just now, I am getting: