He or she will fit a new g.fast socket to the wall and an openreach modem. Then go to the cabinet to connect you after that he will be back to do some checks. Just had mine done he was about an hour the cabinet is just around the corner. Now getting 152 down 29.6 up.
edit: Thanks Martswain got a bit carried away.
Hope this helps
Only advantage is speed was getting 72Mbps took 2mins 45sec to download 1gig now takes 1min 2sec. Grandson thinks it's great he did a speed check on his Nokia one phone and got 138Mbps so he's happy.
Only downside is having to have the openreach modem and Sagemcom hub just something else taking room up.