Buffer-level arbitration is used to allocate released buffers, based on received flow control credits, between local packets and received packets on respective virtual channels in accordance with a determined insertion rate relative to a second number of received packets to be forwarded. An orbiting scroll is eccentrically revolved around an eccentric axial portion of the driving shaft via a bearing. The p-side electrode and the n-side electrode are provided on the semiconductor layer on a side of the second surface.