Hi,
the fault may lie in the phone wiring. you need to plug the hub/router into the master socket test jack, which is located by un-screwing the lower faceplate on the master socket and gently pulling it out. all extension wires should be connected to this, so leave it hanging and plug your router into the socket entry on the right hand side. This will then prove if the fault is with the telephone line or internal. this is important, as the service provider will charge if the fault is in your property, ( £ 130 BT, plus £90 per hour) . If you only have the one socket, no extensions whatsoever, then , yes, it could be the router or hub. if you have extensions, then first job is to un-plug ALL connections from all extension sockets, including the sky box if you have one, and see if that cures the problem. Routers do go faulty, i have attended several properties where they had the same problem, and the routers were faulty, in fact, one property had Talk Talk send a replacement router, and I had to go back because they still could not get onto the net, and this router was also faulty, and what a job I had convincing some girl in India that we needed another one. so, remove everything from the extensions first ( including filters) and proceed. I must just add, that sky boxes are a problem, they send a signal to sky every so often, and this sometimes crashes the net.
Percy.