TalkTalk have lots of small planned work projects happening at the moment. These generally happen from midnight and affect a small number of exchanges at a time. The work does cause service to stop for 30 minutes or longer. TalkTalk publish this information on their status page: https://managed.mytalktalkbusiness.co.uk/network-status/
We are looking at ways of adding these planned works to the Control Pages so as to make it clearer for customers if they are going to be affected.
Whilst there still may be works happening as usual, the bulk of the upgrades that TalkTalk have been doing are over.