UPDATE 2016-12-17 00:06 PST -0800: We are told the maintenance window is closed.
UPDATE 22:04 PST -0800: I think they must have not done the update correctly the first time because there was another ~8 minutes downtime from 21:55 to 22:03. We have not been advised that the maintenance window is closed yet.
We had a network outage of approximately 8 minutes tonight from 21:13 to 21:21 due to an upgrade to the core router software for one of the data centers we have a presence in. There will be a similar outage two days from now.