Thanks for the input, chaps. No GM, I wasn't advised how to check levels or anything similar. However, I spoke today to someone at Virgin who seemed familiar with the situation in my specific area. He confirmed there was a utilisation issue, with upwards of 450 customers trying to use the broadband signal at any one time in peak periods. He said this amounted to almost 100 per cent demand, in fact sometimes "more" than 100 per cent, which the existing system simply can't handle.
The problem apparently centres around the box which links the green cabinet in my street (outside my house actually) to the box which outputs the signal. He seemed fairly confident the issue would be fixed with an upgrade - possibly next month - but was unable to confirm a date. On that basis, I've decided to give it a while longer. Does any of that sound feasible? Is the solution as simple as he said? Am I being naive sticking with a duff service for a few more weeks? Am I asking too many noob questions?
Again, all help gratefully received.