Cabletron Systems 9T428-16 - Manual (Page 26)

Operation
3-2
Figure 3-1. 9T425-16, 9T427-16, and 9T428-16 Block Diagram
All data packets destined for a front panel port, the INB, or the i960 are converted
into the canonical format before forwarding to the SmartSwitch 9000 ASIC.
Network Interface Blocks (NIBs) check for valid data packets entering the system.
If an errored data packet is found, the SmartSwitch 9000 ASIC ßags the error and
does not forward the errored data packet to any outbound ports. Once in this
common format, the SmartSwitch 9000 ASIC decides from header information the
port destination of data packets. Data packets are then converted from the
canonical format to the proper format for the interface destination whether it is a
front panel port, or connection to the INB.
TNIB
The Token Ring Network Interface Block (TNIB) converts Token Ring data
packets received through front panel ports into a common canonical format that
allows the SmartSwitch 9000 ASIC Engine to determine the proper destination
port. The TNIB also converts data packets from the common canonical format
back to Token Ring packets for transmission out front panel ports.
i960
Processor
Smart
Switch
ASIC
TNIB
I
N
B
1
2
SMB 1
SMB 10
DC/DC
Convertor
Diagnostic
Controller
TNIB
TNIB
TNIB
INB
NIB