=OSI Model and Transmission Path=
 A.OSI 7-Layer Model
 B.Signals and Network Media
 C.Data Link Layer
 D.Bridges and Repeaters
 E.ARP and ARP tables
 F.Topologies and Access Methods
  Related Items
 D-1 HUBs
 D-2 Repeaters
 D-3 Bridges and Switches
 D-4 Connection form of HUBs
 ・ Exercise