We will be starting a round of overnight software upgrades to our FireBrick LNSs and routers. We have a large number of LNSs to update and we upgrade one per night. Each line will see one brief drop as it's moved to a new LNS over the coming few weeks. More details on how we perform LNS upgrades can be found here: https://support.aa.net.uk/LNS_Switches
The 'Witless' LNSs will be upgraded first - this will happen this week. Customers on 'Witless' tend to be those with higher speed FTTP services.
The Witless LNSs have been upgraded, we will start upgrading other routers and LNSs - all will happen overnight with very little impact to customers.