Forgot to mention, OVH makes the current topology and traffic saturation of their network switches public: http://weathermap.ovh.net/

(I think they mostly do this so that customers can see and verify that any DC-level peering relationships, or per-customer site peering contracts [a.k.a. "OVHCloud Connect"] are being taken advantage of to flow the customer's traffic. But it's convenient for other things, too.)