utter cobblers being talked about the swanwick problem today
Having read the posts for the day I can advise that its pretty much all cobblers and mis informed guesswork.
Nats have a major contingency provision for a Swanwick failure but its never going to be invoked for a problem of this scale.
The systems are fully redundant in thread terms but if the software causes a common mode problem it will affect all the redundancy in the affected systems
NATS would need to fully duplicate all systems at the controller position and the servers and networks on completely different operating systems, platform and application software to negate any common mode faults.
That scale of redundant provision with all the development, support etc overheads would be a massive additional cost and is just a complete non starter