The SDCC channels provide an in-band management path within a fiber rings, of which there are two interfaces—one for each side of the fiber. It's a point to point topology. Multiple SDCCs become multiple paths or even rings. Using CTM or CTC, you can...

Yes, it can. You can have multiple UPSR/BLSR rings and be able to span a circuit across a DCC domain as long as there is a path to both ends, ie all rings are connected via SDCC.