3Com CoreBuilder 9000 Quick Start Manual page 6

6 20-Port 100BASE-FX (MT-RJ) Fast Ethernet Layer 2 Switching Module Quick Start Guide
Module Placement
in the Chassis
Note the following chassis slot restrictions and recommendations when
you choose a chassis slot for the 20-port 100BASE-FX (MT-RJ) Fast
Ethernet Switching Module:
In the CoreBuilder 9000 7-slot chassis:
Install a FEN Switching Module in slot 1, 2, 3, 4, 5, or 6.
Do not install a FEN Switching Module in slot 7. This slot is reserved
for a GEN Switch Fabric Module.
In the CoreBuilder 9000 8-slot chassis:
Install a FEN Switching Module in slot 1, 2, 3, 4, 5, or 6.
Do not install a FEN Switching Module in slot 7 or slot 8. These
slots are reserved for GEN Switch Fabric Modules.
In a CoreBuilder 9000 16-slot chassis:
To optimize backplane performance, install 20-port FEN Switching
Modules in slot 1, 2, 3, 4, 5, 6, 7, 10, 11, or 12.
Do not install a FEN Switching Module in slot 8 or slot 9. These
slots are reserved for GEN Switch Fabric Modules.
Table 1, Table 2, and Table 3 list the relationship among the 24-port
Gigabit Ethernet (GEN) Switch Fabric Module (Model Number
3CB9FG24T), the 20-port FEN Switching Module, and the slots in the
7-slot chassis, the 8-slot chassis, and the 16-slot chassis, respectively.
Table 4 and Table 5 list the relationship between the 9-port Gigabit
Ethernet (GEN) Switch Fabric Module (Model Number 3CB9FG9) and the
the slots in the 7-slot chassis and the 8-slot chassis.
Use this information to help select a slot for your module, as well as for
administration purposes after you have completed the installation.