-Other carriers having small short outages is most likely overload of available capacity. Shared infrastructure as well between carriers will have reduced some of the capacity for Bell, Telus, etc.
-Ransomware or Cyber Attack is not likely (but I agree, not totally impossible). The internal networking of a carrier is completely isolated from the business network (email, billing, customer service, etc) so the attack footprint is small to none.
-My hunch is a major fuck up in the core networking. A really bad BGP configuration (for my fellow networking gurus) replicated nationwide and now they have to manually update all the core networking that it broke. Was this a mistake or planned attack by an internal employee(s)? If true, time will tell.
-Those suggesting more competition in Canada fail to realize the billions and billions and billions of last mile infrastructure/core infrastructure it would take for a new competitor entering the Canadian market would need to invest to truly reach Bell/Rogers/Telus level. Wind/Freedom Mobile has been 10+ years developing in Canada and done well but still a fraction of the infrastructure the big carriers have invested in. With a market of only 38-40 million Canadians spread across such great distance (so much low density populations that would need service as well as the denser big cities) and yes a lot of government red tape doesn't help either - makes it doubtful for any large player to enter the Canadian market is my opinion.
-A lot of end points on a single carrier connectivity (Rogers in this case) today will be reviewed and consideration for a failover solution to a second carrier where possible - ATMs for example. Cost and capacity permitting in a case by case basis of course.
Just my $0.02 on the day. Hope everyone is well and pray this is resolved by the morning.