How are data centers typically interconnected?
I know this is a loaded question with many different variables, but I am looking for a semi-high level explanation.
Lets say that the 2 data centers are connected through some fiber mux solution, like CWDM or DWDM, etc, what network device is the fiber mux usually connected to? In other words, what is the tap-off point?
Is it the data center's core switches? Or is there a WAN Edge distribution layer that hangs off the core that these fiber muxes would be plugged into? It can be both either, right?
Can someone kindly elaborate on different inter-connectivity models? You can talk about different facilities that can be used, different tap-off points in each data center....etc etc
PS, I know there are documents and if you have one, great, BUT can you please elaborate a bit on your own from your own real world experiences?