How does w2go app work with my book live

Can anyone explain or point me to paper which explains how does mybook live works. for example…

how does it provide ip to be access from outside world

how does w2go knows to connect to mybook live from outside internet?

The MBL registers itself with WD’s servers when you configure Remote Access / Web Access on the MBL.

When you access the MBL from a remote PC, you’re using a WD2GO.COM network address, which works pretty much the same as Dynamic DNS.

ok so when you lets say watch a movie on w2go when MBL sends content back to w2go does it go first trought WD servers and then to my w2go or it goes directly to w2go

From what I can tell, it’s going direct to the device.  

However, I’m not sure what happens if the MBL is in “Relay” mode…  All of mine are in Port Forwarding mode (which is the desired mode.)