3Com 3C780 User Guide - Page 165

4 Glossary MAC MIB MIC Noncanonical order Null attachment concentrator Optical bypass Peer-mode connection Media Access Control. MAC, the OSI access layer, specifies the access mechanism used by FDDI nodes for transmitting and receiving data on the ring. The MAC is responsible for receiving frames and transmitting frames according to the rules of a timed token rotation protocol, a dynamic protocol unique to FDDI. Management Information Base. A set of FDDI-managed objects. The MIB defines the data that a network manager can expect to get about a managed device. It defines the access permissions for each data item, and the size, type, and semantics of each data item. Media Interface Connector. A mated connector pair that provides an attachment between an FDDI node and a fiberoptic cable. MIC connectors are normally keyed, both to prevent accidental reversal of transmit and receive fibers and to ensure connection only to ports of the correct type. The agreed upon bit order of transmission. Noncanonical addressing is when the most significant bit of the most significant byte is transmitted first. The FDDI hub's MAC/ SMT address appears in noncanonical order when the show sid command is issued. A concentrator that can be considered a self-contained FDDI network but is not connected to a dual ring backbone. It does not contain an A, B, or S port. An optional facility that allows the FDDI optical signal to bypass FDDI nodes when they are powered off. A connection between peer ports (A, B, and S ports).