Specifications

A.9 FDDI in the Hub Backplane
FDDI Configuration Capabilities A–11
A.9 FDDI in the Hub Backplane
The DEChub 900 MultiSwitch and the DEChub ONE-MX use a building block
approach for configuring FDDI on the backplane. The network manager assigns a
port type by selecting a building block.
A.9.1 FDDI Building Blocks
Building blocks are divided into two groups:
• Ring Building Blocks
• Tree Building Blocks
There are nine building blocks; four are used for building dual rings, and five are
used for building trees.
MultiChassis Manager only allows connections to be made between building blocks
of the same group (ring group or tree group), in order to avoid errors such as connec-
tions that break because of the FDDI standard’s preference for trees over dual rings.
A.9.2 Ring Building Blocks
The four ring building blocks, see Figure A–8, are as follows:
Name Description
Trunk B Port A connects to the FDDI network module front panel
ports. Port B connects to the DEChub 900 backplane or
to the DEChub ONE-MX ModPMD.
Trunk AB Ports A and B connect to the DEChub 900 backplane or
to the DEChub ONE-MX ModPMD.
Trunk A Port A connects to the DEChub 900 backplane or to the
DEChub ONE-MX ModPMD. Port B connects to the
FDDI network module front panel port.
Stump Primary Ports A and B connect to the FDDI network module’s
front panel port.