Operation
3-6
System Diagnostic Controller
This diagnostic controller is composed of a Z-80 microprocessor and its
supporting logic. The diagnostic controller is designed to control the power-up
sequencing of modules, monitor the 9T425-16, 9T427-16, and 9T428-16 input and
output power parameters, keep watch over the main host processor, as well as
monitor the temperature and control the SMB LANVIEW diagnostic LED.
Although the diagnostic controller and the main host processor can operate
independent of each other if needed, they exchange information about each
otherÕs status and overall module condition. The information gathered by the
diagnostic controller is available to the network manager via local/remote
management and the LCD located on the environment module. The 9T425-16,
9T427-16, and 9T428-16 have been designed so that in the event of a diagnostic
controller fault, the modules will continue to function.
DC/DC Converter
The DC/DC converter converts the 48 VDC on the system power bus to the
necessary operating voltages for its host network services module. The diagnostic
controller controls the operation of the DC/DC converter.
INB NIB
Each module that attaches to the Internal Network Bus (INB) has an INB Network
Interface Block (NIB). The INB NIB converts canonical frames to Þxed length data
blocks for transmission onto the INB. For data blocks received from the INB, the
INB NIB reassembles the data blocks received from the INB back into canonical
frames for transmission to the SmartSwitch 9000 ASIC then from the SmartSwitch
9000 ASIC to the front panel ports.
SecureFast Switch
The SmartSwitch 9000 ASIC is a hardware based switch design that is the key
building block of the SmartSwitch 9000. All Þltering/forwarding decisions are
made in hardware as opposed to software as in traditional switches. This custom
hardware allows the SmartSwitch 9000 ASIC to process over 750K frames per
second. The SmartSwitch 9000 ASIC is designed to support up to 64 ports that are
shared between the host processor, the INB backplane, and LAN/WAN interfaces
on the front panel of SmartSwitch 9000 modules. The SmartSwitch 9000 ASIC can
operate in two modes: as a traditional switch, or as a SecureFast Switch (SFS).
When operating in traditional switch mode, it makes Þltering/forwarding
decisions based on Destination Address (DA), with standard IEEE 802.1d
