I didn't reply to your first post, as I don't really like to publicly disclose many details of our infrastructure. But a very basic answer is that we use a combination of leased and owned equipment. Generally speaking, it is very easy for us to move back and forth between the two types of equipment, and we're not solely dependent on either one functioning at any given time, although there could be some temporary service interruption during swap overs.
That's a killer answer to the question!
Didn't necessarily expect you to necessarily have to answer, but I'm glad you took the time to share that. Good answer.