Cabletron Systems 9C106, Setup And Installation Manual

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Introduction

System Management Bus 10

The System Management Bus 10, or SMB-10, performs similar functions to those 
of the SMB-1 previously discussed in this section. The SMB-10 bus is devoted to 
the transfer of management data within the chassis, but is used for out-of-band or 
Local Management operations. The SMB-10 operates at Ethernet speeds of 
10 Mbps, and is connected to any manageable module in the chassis. Access to the 
SMB-10 for Local Management operations is provided through an Ethernet Port 
Interface Module (EPIM) slot on the 9C306 System Monitor, or through the serial 
COM ports, also located on the System Monitor. The SMB-10 can also be accessed 
from in-band management through a Telnet application.

The Flexible Network Buses

The Flexible Network Buses, FNB-1 and FNB-2, are the primary backplane buses 
used to connect SmartSwitch 9000 modules for shared network designs. Each 
FNB bus operates as a dual, counterrotating Fiber Distributed Data Interface 
(FDDI) ring. Each FNB bus operates at 100 Mbps, and consists of one primary ring 
and its associated secondary ring. In the event of a failure of a station or a 
connection, the signals from the primary ring are wrapped onto the secondary 
ring, creating a single ring and allowing network trafÞc to continue circulating. 
The construction of the FNB backplanes includes shunting connectors which 
allow network signals to pass by unpopulated slots in the chassis. This design 
frees Network Managers from a dependence on speciÞc ordering or placement of 
modules, and allows modules to be removed from the FNB without causing a 
wrap of the FDDI ring.

The Internal Network Buses

The Internal Network Buses, abbreviated INB-1 and INB-2, are designed to 
simultaneously support both packet and ATM cell transport. Each INB data 
channel is 64 bits wide (56-byte data bus and 8-byte management and control bus) 
and runs at a clock rate of 40 MHz, yielding a sustained data rate of 2 Gbps, and a 
burst rate of 2.5 Gbps. The 8-byte management and control bus allows all 
signaling and bus arbitration functions to occur out-of-band with regard to user 
data. 

The Cell Transfer Matrix (installed in the 9C706 chassis only)

The Cell Transfer Matrix provides a Time Division Multiplexed (TDM) based 
mesh of full duplex, high speed (1.6 Gbps) dedicated interconnections capable of 
carrying standard ATM cell trafÞc. These interconnections are a series of point-to-
point links between an individual module, and every other module that directly 
connects to the Cell Transfer Matrix. If the 9C706 chassis has 6 modules that 
connect to the CTM installed, there are 30 point-to-point links between all the 
modules, providing a total aggregate switching capacity of 32 Gbps.