1 The obvious next step is to integrate paths through the end host with circuits between hosts, but for the purpose of this paper, we focus on paths within a single system.
2 Although layering does not imply multiple protection domains, systems often impose hardware-enforced protection at layer boundaries.
3 Because it is difficult to compute globally meaningful priorities for RM scheduling in a dynamic system---i.e., one where different rate videos come and go---single-priority round-robin is the next best alternative. Therefore, we compare EDF to this case, rather than to RM.