Are you getting the same error on both boxes as it usually only affects one? If it's both boxes then have you used the /check-services/ function to check for problems in your area? You can also a run a test on your equipment from there.
If nothing is showing you could also try the automated Service Status number 0800 561 0061. This is generally better as it gives details of more local issues down to postcode level.
CS2002 is a channel failed error, and the usual advice is to check your cabling, especially that the white coaxial is secure and free from any kinks, and the small connector cable that goes into the back of the 360 which can be very pliable. If you are using an ethernet cable then make sure that it is snug and tight, also reboot both the 360 and hub at the same time so they can make the handshake again.