You basically have to hookup Cloud Provider A through a middle layer to Cloud Provider B (e.g., connect via Equinix or Megaport). It’s not drastically different than a hybrid setup, except you don’t control the premises on either side.

While getting you the right link to our Partner Interconnect docs, it turns out we have a nice solution guide writing up the various options [1].

The costs boil down to some non-trivial fixed price each month to cover the 1/10/100+ Gbps connection on each side, plus whatever transfer fees each provider charges for egress over that method. At large enough volumes, providers of all sorts usually have equivalent fixed prices. Getting multiple redundant lines, or doing VPN encryption, obviously costs more and is more work than “just a pipe”.

Even at list prices though, this gets you closer to $.02/GB each way in Europe or North America. At high volume in the same metro area (like Northern Virginia), you can easily agree to much lower rates on either side.

[1] https://cloud.google.com/solutions/patterns-for-connecting-o...