Cabletron Systems MMAC-Plus 9H421-12, Руководство пользователя

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3-1
Chapter 3
Operation
The 9H422-12 is a twelve port switch module, with eleven 10BASE-T/100BASE-
TX ports and one FEPIM (Fast Ethernet Port Interface Module), on the front panel.
The FEPIM port accepts either the FE-100TX, for use with twisted pair copper, or
the FE-100FX, for use with mulitmode fiber optic cabling. The 9H421-12 is a
twelve port switch module, equipped with twelve multimode fiber 100BASE-FX
ports. The 9H429-12 is a twelve port switch module, equipped with twelve single
mode fiber 100BASE-FX ports.
The 9H422-12 is 10BASE-T and 100BASE-TX compatible and provides auto-
negotiation for automatic speed selection. The 9H421-12 and 9H429-12 are
100BASE-FX compatible and operate only at 100 Mbps.
Each module can operate in either full duplex or half duplex mode. Auto-
negotiation for 100BASE-T modules provides support for 10 Mbps and 100 Mbps
speeds at both half and full duplex. 100BASE-FX supports 100 Mbps speed at both
half and full duplex.
As shown in Figure 3-1, Fast Ethernet Network Interface Blocks (FENIBs) convert
data packets received from any of the front panel ports into a canonical frame
format before forwarding to the SmartSwitch ASIC, 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 SmartSwitch ASIC. The
FENIBs are each designed to handle traffic from two front panel ports.