Superfast download speed lower than upload in the evenings

[NickDFC]

Greetings all

I was relieved to read other posts describing the same symptoms that I am experiencing, which means there is still hope 🙂

For several years I have enjoyed superfast broadband speeds of 70 - 72 Mbps down / 18 Mbps up and the service has been more reliable than the previous ADSL. However starting about two months ago the evening speed drops from over 70 Mbps to 5 or 6 Mbps from 6pm onwards, then recovers after midnight. This is a daily occurrence although there are occasional remission days. The upload speed is always 18 Mbps at any time of day. The hub syncs at 79.999 / 19.999 and this never changes.

I am measuring speeds using the BT Wholesale speed checker with a wired Ethernet connection and light loading. So far I have had three visits from Openreach engineers who were as helpful as they could be but could not find any physical reason. The line is in good condition and shows no errors. One engineer changed a card in the roadside cabinet (which I can see from my house), and I have also been sent a new hub but neither made any difference.

I was told by one engineer that it was caused by something that I was doing such as sustained backup or downloads, but I have checked everything and do not believe that to be the case. It does not correspond to the daily pattern, and the status page on the hub does not indicate any increased download activity during the evening.

I am connected to cabinet 4 on the CARBOST exchange. Many of the posts about similar issues have mentioned SVLAN issues and that mods may be able to help. I would be glad to post more details or make other tests if anyone can help me to move forwards.

Thank you for reading 🙂

[NeilO]

Hi @NickDFC its not something that we encounter much anymore but the symtoms do sound like it could be congestion on the SVLAN. I'll send you a private message so you can get in touch and we can ask our network specialists to take a look.

Thanks

Neil

[NickDFC]

Thank you @NeilO 

[NickDFC]

Unfortunately this has hit a wall of silence after ten weeks. I have had seven engineer visits, endless tests and resets, a new router and a new card in the cabinet. OpenReach now confirm that it is not a local fault, and there is an issue somewhere in the network. On the same cabinet I am aware of one user who has the same symptoms, and one who still gets full speed during the evening. Some of the engineers completely ignored the information about the daily speed drop off and overnight recovery, some said "fibre doesn't do that", and one said I should not be trying to use streaming services (although they are happy to take the money for it). 

BT Internet has given me some compensation and unilaterally closed the support case, stating that they cannot do any more because OpenReach will not tell them when or even if this will be fixed. They reminded me that under the terms of the speed "guarantee", I am now free to leave without penalty. But they also pointed out that a service from any other ISP will face the same issue and little prospect of a resolution. I should not expect to hear from BT Internet, and OpenReach do not contact customers direct.

I am left paying a premium price for a service that is below the headline speed for one third of the day, and drops to 4 Mbps on bad evenings. At 4Mbps everything stutters and web meetings are difficult. I can understand that BT and OpenReach need to shed intractable accounts where there is no reasonable prospect of delivering an acceptable service, like needing to dig up an entire road for one customer. But my FTTC internet has worked well for many years and has only recently deteriorated.

[NickDFC]

@NeilO   @DavidM  @StuartH 

[Steve_M]

I'm happy to take a look next week when i'm back in the office if you drop me the details in a PM

Steve

[NickDFC · Accepted solution]

In case anyone else experiences the same thing, this was the solution in my case: the VLAN to which I was allocated had been omitted from the automatic load balancing system, which meant that when congestion occurred, the system did not automatically detect and correct it. This has now been resolved by OpenReach and I am back to normal speeds.

[NeilO]

@NickDFC Brilliant, I'm glad that's sorted.