Hiya J.Man, welcome aboard.
A line attenuation of below 30dB is generally considered to be quite a short line. Therefore you should be getting a steady, good, 8Mb sync.
I am completely baffled by what's going on with this, can I ask you if your attenuation varies at all? Or does it remain constant?
This problem isn't going to go away without a BT engineer visiting to see what's going wrong somewhere. If your sync speed has dropped to 500k, you need to contact BT and get them to send an engineer to you too
Please note, sync speed is the connection speed reported by your modem/router, and is, as far as this fault is concerned, ENTIRELY unrelated to your IP profile.
>> you may notice my IP is the same as his
Hmm, that wouldn't happen, at all, unless you were both physically on the same Internet connection. Stuff like IP addresses messing up would be affecting either a very large number of BT Internet users, or none at all.
Like I said, the issue appears to be with the lines themselves, perhaps a bad underground/overground cable somewhere that's common to your street - maybe one feeding a cab or something.
So J.Man, everyone who's line sync has dropped to 500k in your street needs to contact their ISPs to get it sorted. Before you do, just make sure that you have followed some basic troubleshooting - mainly try the connection in the test socket, behind the master faceplate, and see if you still sync at 512k, and if your attenuation still fluctuates (if applicable).
This is to avoid a red face and being out of pocket if an engineer turns up and says it's a problem with your equipment, which I doubt, judging by what I've read in this thread.
But as I said, there's not a lot more we can help with, it needs an engineer to sort it. If it really is as bad as Broadband1 has been telling us (and I have no reason to doubt that), then an engineer should come round, and easily spot the problem.
So when you ring BT you say your attenuation is *blah* your SNR is *blah* and your downstream/upstream sync speeds are *blah*. You should probably mention that a lot of your neighbours, some who are also with BT, are having the exact same problem, and specifically request an engineer comes to look at it.
Good luck