DEChub Network Modules 900-Series Concentrator Reference

This document serves as a comprehensive reference for the DIGITAL DEChub 900-Series family of Fiber Distributed Data Interface (FDDI) concentrators. It is intended for both pre-sales technical support and post-sales customer service personnel.

The manual introduces the fundamental concepts of FDDI networks, explaining the role and architecture of concentrators (Single Attachment Concentrators - SAC, Dual Attachment Concentrators - DAC) and station types (Single Attachment Stations - SAS, Dual Attachment Stations - DAS) in various physical topologies such as standalone, tree, and dual ring of trees. The concentrator architecture details components like Station Management (SMT), Media Access Control (MAC), Physical Layer Protocol (PHY) entities, Physical Layer Medium Dependent (PMD) modules, and the configuration switch.

Specific DEChub 900-Series concentrator models—the 900MX, 900TH, and 900FH—are described in detail. This includes their port configurations (fixed and modular), supported media options (multimode fiber, single-mode fiber, unshielded twisted-pair), physical dimensions, operating specifications, and advanced features like dual homing, auto healing, optical bypass relay (OBR), and SNMP manageability. The document also provides ordering information for these modules and their PMD options.

The document extensively covers FDDI configuration capabilities, illustrating how dual ring and tree topologies can be created using building blocks within the DEChub 900 backplane or with standalone modules. It highlights fault tolerance features such as auto healing for recovering from failed modules and dual homing for redundant connections, along with the Quick PC Trace option designed to accelerate network recovery after a beacon error.

Finally, the manual guides users on managing FDDI concentrators using the clearVISN MultiChassis Manager, detailing tasks like viewing configuration and network utilization, configuring concentrator ports and timers, and setting link error rate thresholds. Appendices further provide an overview of FDDI standards and concepts, instructions for repairing corrupted nonvolatile flash memory, and specifications for various fiber optic and twisted-pair cables.