It's also worth noting that in most cases on-net caches (in ISPs) aren't as common as people think. It's mostly private peering at public data centres. Google d

It's also worth noting that in most cases on-net caches (in ISPs) aren't as common as people think. It's mostly private peering at public data centres. Google doesn't have servers in all ISPs, this was more common in the past than today.