We have multiple interlinks with BT in separate datacentres, however, BT need to make a change to their Core Network that will unfortunately impact all BT services. (Etherway/Etherflow services are not affected)
BT are simultaneously upgrading some 21C network software across multiple sites. The window is 8th November 00:01 until 07:00, and will start at 00:01 with non-disruptive pre-checks. From 01:00 BT will start to re-boot the devices to the new version of code. This will cause an outage to all customers of up to 15 minutes whilst the device restarts. However, if roll-back is required, the outage could exceed 1hr. All work will be complete by 07:00.
...We have asked BT why they can't stagger the work, and cleanly move traffic as they do.
BT will be rescheduling this, they say "This is to advise you that this Change on the BT UK Core Network is being rescheduled and will NOT take place on 08/11/2023 00:01."