Specifications

A.17 Summary of Important Configuration Features

FDDI Configuration Capabilities A–41

Figure A–32 Illegal Dual Ring of Trees Topology

A.17.6 Dual Homing

Dual-homing to multiple FDDI modules in a DEChub 900 can be supported in two

ways:

• Each module can be individually dual-homed via its front panel ports (assuming

the module has front panel ports)

• One concentrator module can be dual-homed and the other FDDI modules can

be treed off that concentrator

A.17.7 Chaining

Additional DEChubs or standalone FDDI network modules can be chained off any

DEChub FDDI network module (including switches) that is configured as a tree

building block.

A.17.8 Self-Contained Dual Ring Restriction

Attempting to build a self-contained dual ring configuration in the DEChub with

eight FDDI modules will not work. This is because there are 14 backplane channels

that can be used for FDDI connections and 16 channels would be required to inter-

connect 8 modules in a hub-contained dual ring. Note that this configuration can be

accomplished with 14 backplane channels and one DAS cable between two device’s

front panel ports.

LKG-10089-96F

Front Panel Ports

Backplane ports

BAMSMSM