Jeroen van der Ham wrote:

[...] for Link we indeed decided that it was possible to have a loopback link. However, for Crossconnect we did agree that it must be in the same device.

Indeed. By the way: I once described a patchpanel as different "devices" and fixed fibers on the backend were described as "cross connects", thus between different "devices". I'm not sure how I would describe it nowadays -- possibly as ports with a link on each side, without a cross connect. Regards, Freek