I have been using 120Mbps Virgin Cable Broadband near Portsmouth, UK for over a year now and been able to download files and updates from most servers at around 11 MB/sec, untill about 5 weeks ago.
Then suddenly over night, virtually all downloads & update speeds have drasticlly reduced to around 450 KB/sec when the download starts and within less than a minute has reduced to around 50KB/sec and then slows further stile to less than 56k modem speeds, sometimes in a few seconds, and more often than not stops halfway through, 0KB/sec. Even worse still some websites are unreachable. Just one of many for example http://www.freeview.co.uk/ . They eventually time out and I just get a blank page.
Also streaming video from youtube starts on default 480 resolution then sometimes drops to lower resolutions and buffers and stops. Audio from BBC iPlayer radio buffers constantly then stops.
iTunes updates start slow and stop before finishing, so unable to update. Mobile apps are the same so unable to update over wi-fi, only on 3G.
This all happens on all my devices while connected through Virgin cable, over ethernet cable with 1Gbps to superhub 2 connections with windows 7 x2 PC's ( with or without anti-virus installed) and 2x PC's with 1Gbps ethernet connections with Ubuntu Linux installed. Also happens iPhone & Android on 5GHz Wi-fi to Superhub2.
All devices work perfectly when connected to 3G internet, with faster download speeds, all downloads finish and all the websites I cannot get on virgin cable are availble over 3G mobile internet. Even on windows 7 PC's and Linux PC's when I conect to 3G internet via wi-fi to either of my phones using the built-in wireless hotspot feature. So I know all my devices are working correctly, and the only common failure is Virgin cable.
What is stranger still, is if I use OOKLA speednet's test, it says I have 128Mbps download speed (11Mbps upload)on all my ethernet connected devices and 80Mbps d/l (11mbps upload) on 5GHz wi-fi devices on virgin cable. But that is the only thing that does. It says 2.9Mbps TBBx1 & 23Mbps HTTPx6 on this sites test for example (11Mbps upload). All other speed tests i've tried say around 5Mbps download and 11Mbps upload.
Does anyone know why OOKLA's test is good and all other tests have half the download speed of the upload speed on all devices?
When the Virgin Media technician arrived and before I had a chance to say anything about my problems, the first thing he did was connected his mobile device over my 5GHz wi-fi and said "Theres is nothing wrong with it". And showed me his speed test result on OOKLA speedtest ( I thought it was bit strange that he would use that as his official test of my internet connection ).
When I demonstrated the actual problems, he blamed every single problem through the virgin cable connection as a problem with every site I was going to & that if his speedtest on OOKLA was good then theres nothing wrong.
When I demonstrated everything works fine over 3G internet including my 2 windows 7 PC's and 2 Linux PC's, he said "it's done differently on 3G" and his comparrison was "You will get some websites over 3G internet that you won't get on virgin cable internet. Just like you won't get Sky movies on freeview televison!" I was dumbfounded & almost speechless that he said that.
So after an argument that almost sounded like a Monty Python sketch from the point of view of anyone that might have been listening in, he fitted a brand new superhub 2, coax & splitter.
Guess what! It was still the same!
Any thoughts and ideas would be appreciated folks.
Thanks in advance.