Operation
3-2
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.
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 1 Mbps management bus located within the SmartSwitch 9000.
This bus is utilized by all diagnostic controllers in the system. These include
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 tests are performed by all modules that 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.
SMB-10 Bus
The SMB-10 is a 10 Mbps management bus located within the SmartSwitch 9000,
which is also used for inter-chassis communication of modules as well as serving
as an out-of-band management channel into the SmartSwitch 9000. The SMB-10 is
externalized from the chassis via an optional Ethernet Port Interface Module
(EPIM) located on the front of the Environmental Module. Through an EPIM
connection, full SNMP management of the SmartSwitch 9000 is available out-of-
band from user data. Modules which share the SMB-10 bus periodically send out
loop-back packets to ensure the validity of SMB-10. In the event a fault is detected
on the SMB-10, the SMB-1 can be used as an alternate communication channel by
the modules. Non-runtime downloads and BootP downloads also utilize the
SMB-10 bus.