Spanning Tree Algorithm; Flexible Network Bus (Fnb); System Management Buses; Smb-1 Bus - Cabletron Systems SmartSwitch 9000 User Manual

Operation

Spanning Tree Algorithm

The 9T122-08 promotes maximum network use in multiple bridge environments.
A bridge learns the bridge topology of its network from bridge protocol data that
it receives from other bridges within the network. The bridges then apply the
Spanning Tree Algorithm (STA) to select a root bridge, and then determine
primary data paths within potential data loop configurations.
Spanning Tree Algorithm is a hierarchy (or tree) of priorities that bridges establish
between themselves. This hierarchy guarantees that primary and redundant data
paths are clearly defined at all times, so that the network is continuously available
to users.
In a multiple bridge environment, one bridge in the network establishes itself as
the root bridge. As the root, this bridge has priority over all other bridges. In a
Spanning Tree, all of the bridges must determine which bridge is the root, and
then determine their own relative priority within the network.

Flexible Network Bus (FNB)

The FNB consists of two dual FDDI networks, the FNB-1 and FNB-2, providing
up to 400 Mbps of data bandwidth. These FDDI networks are 100% ANSI
FDDI-compliant supporting SMT (version 7.3), MAC, PHY, and PMD standards.
This allows the FNB to traverse multiple SmartSwitch 9000 hubs, or connect to
any ANSI FDDI-compliant device, through standard A/B port connections, using
the FDDI repeater module.

System Management Buses

There are two management channels within the SmartSwitch 9000 system: the
SMB-1 and the SMB-10. These buses provide out-of-band management and inter-
module management communication.

SMB-1 Bus

The SMB-1 is a 1Mbs management bus located within the SmartSwitch 9000. This
bus is utilized by all diagnostic controllers in the system including connectivity
modules, power supply modules and the environmental module. The SMB-1
transports inter-chassis information between system components, such as power
and environmental information, as well as diagnostic messages. Periodic
loop-back test are preformed by all modules which share this bus to ensure the
validity of SMB-1. In the event a failure is detected on SMB-1, the SMB-10 may be
used as an alternate communication channel.
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