Specifications

A.11 FDDI Tree Configuration Examples
FDDI Configuration Capabilities A–19
A.11.2 Example 2 — Self-contained Tree of Switches and Concentrators
in Hub Backplane
In this example (see Figure A–12), an FDDI tree is constructed entirely within the
hub backplane; however, a mixture of FDDI network module types (switches and
concentrators) is used. The backplane ports of the FDDI network modules are
enabled as M ports and S ports. The front panel ports of the concentrators become M
ports, and the front panel FDDI ports of the switches become unusable.
The module that is installed in the highest slot number of the hub (DECswitch
900EF) is designated as the top of the tree, and its M port connects to the S port of
the module with the second highest slot number (PEswitch 900TX).
Two hub backplane channels are required for each connection. In Figure A–12, a
total of four backplane channels are in use.
Figure A–12 Tree Connections with Switches and Concentrators
Figure A–13 shows the building block representation of the configuration example
described in Figure A–12.
MMMMMM
Front Panel Ports
LKG-10076-96F
Backplane Ports
DECconcentrator 900TH PEswitch 900TX DECswitch 900EF
MSMSMS