1-1

Chapter 1

Introduction
The 9T122-24 MicroLAN™ Switch Module, shown in Figure 1-1, is a three port
Token Ring bridge and router module. This module supports either one token
ring with twenty four HUB connections, or two separate Token Rings with twelve
HUB connections, and an interface to the FNB backplane.

Features

Processor
The 9T122-24 is equipped with an advanced Intel i960 microprocessor. This
microprocessor provides a platform for all management functions within a
scalable RISC-based architecture.
System Management
Interfaces to the two System Management Buses (SMB-1 and SMB-10) for
intermodule management.
Connectivity
The 9T122-24 provides twenty four RJ-45 Trunk Coupling Unit (TCU) lobe
connectors. The connectors may be configured as one twenty four port ring
(default) or two twelve ports rings.
Bridging/Routing
Bridging/Routing between the front panel Token Ring connections and/or to any
other module in the chassis via FNB -1 or FNB -2 of the FNB bus. The module is
capable of Transparent Bridging or Source Route Bridging. IEEE 802.1d Spanning
Tree Protocol is supported in all bridging functions. Translational bridging
between Source Routing and Transparent Frames types is also performed.