Enterasys 9e312-12 Manuel D’Utilisation

Page de 29
 
3-1
 
Chapter 3
 
Operation
 
The 9E312-12 module is a thirteen port device; twelve front panel ports, each 
represents a separate Ethernet collision domain and one port connected to INB1. 
As shown in Figure 3-1, Ethernet Network Interface Blocks (ENIBs) convert data 
packets received from any front panel port into a canonical frame format before 
forwarding to the Fast Packet Switch (FPS), while the Internal Network Bus 
Network Interface Block (INB NIB) converts data packets received from the INB 
into a canonical format before forwarding to the (FPS). All data packets destined 
for a front panel port, the INB, or i960 are converted into the canonical format 
before forwarding to the FPS. Network Interface Blocks (NIBS) check for valid 
data packets entering the system. If an errored data packet is found, the FPS flags 
the error and does not forward the errored data packet to any outbound ports. 
Once in this common format, the FPS 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.
 
Figure 3-1. Packet Flow
i960
Processor
Fast
Packet
Switch
ENIB
ENIB
ENIB
I
N
B
1
2
INB
NIB
SMB 1
SMB 10
DC/DC
Convertor
Diagnostic
Controller
12
Front
Panel
Ports