We are aware of at least three providers affected by problems in the East Lothian area, specifically the Tranent, Prestonpans and Musselburgh exchange areas.
Customers of BT, TalkTalk and Sky all with the fibre based services at the provider are reporting corrupt downloads of large files and problems with streaming video. The corrupt downloads problem is potentially serious as if you are updating the firmware of a device that does not perform checksums on any downloaded files you might end up with a dead device.
We have tracked down what looks to be a regular speed test user on the Tranent exchange and the speed test results are showing what would normally be classed as a congestion problem, but congestion should not normally exhibit as corrupt data packets. A couple of weeks ago you can see that the same user had a never nicely behaved connection with a stable 63 Mbps download speed (the user has many more speed tests but we have featured the two that appear to demonstrate what is happening for users).
We have asked for more information on what is the actual problem, but given three threads that are already running BT, Sky and TalkTalk and service status checkers are just referring to problems in the area we are not hopeful on getting a short concise answer.
If you are not sure if you are affected, our download test files and their MD5SUMS are available for those wanting to verify large file downloads. Also in addition to our usual speed test options, you can run our speed test over SSL though for those on connections over 400-500 Mbps we have found that browser and PC performance can be a limiting factor when handling SSL traffic.
Update 10am Tuesday Zen Internet status page is monitoring the work that is still on-going to fix the problem, several things appear to have been tried but the fault is persisting.