CIT’s FDDI Troubleshooting

## Copyright © 1999 Boson Software

Written by kevin@boson.com

FDDI SPECIFICATIONS:

- MAC (Media Access Control) specifies media access parameters such as formatting of frames and how the CRC is calculated.

- PHY (Physical Layer Protocol) specifies encoding/decoding and clocking.

- PMD (Physical Layer Medium) specifies electrical characteristics of the transmission medium.

- SMT (Station Management) specifies how a ring is configured and how a station is inserted or removed from the ring.

FDDI CONNECTION STATES:

- States A and B both indicate an established connection with either a DAS or a concentrator.

- State M indicates an established connection with a neighbor acting as a master to a connected station or concentrator.

- State S indicates an established connection with a SAS.

- State unk indicates that a connection has not been established with a neighbor.