GarrettCom Magnum 3000 Manual De Usuario

Magnum 3000 Stackable Hubs                                   Installation and User Guide (07/06)

 

 

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The IRB ribbon cables supplied with each Magnum 3000 base unit are slightly 

longer than the base unit height.  Thus, an IRB cable segment has a small arc shape when 

it is properly installed.  It is possible to have some long IRB ribbon cable segments, up to 

a few meters in length, for service loops and such.  The operation of the stack will not be 

impaired by longer IRB ribbon cables.  Stacks with total IRB lengths of as much as ten 

meters can be implemented.  However, non-standard IRB cable lengths must be specially 

made. 

The IRB ribbon cables may be installed and/or removed while a Magnum 3000 

unit is powered without causing damage to the electronic circuits in that unit or any 

others in a Magnum 3000 stack.  This is convenient for expanding a stack without 

shutting down the network, and for performing diagnostics and service on potentially 

faulty units operating in a stack.  CAUTION: disconnecting an IRB ribbon cable can 

cause operational upsets by breaking the interconnection among the stacked units 

previously operating as a single repeater and/or with one SNMP agent. 

 

Magnum 3000 Stackable Hubs are typically stacked as described in Section 

2.3.1.  However, it may be desirable to stack the 3000s so that they operate as separate 

repeater units.  This will normally be done to manage several separate hubs (or small 

stacks) with a single 3000 AGT SNMP Agent box.  In this situation, single units or 

several small stacks of units may be connected using SRC Segmenting Cables (part 

numbers SRC-2 and SRC-4, available as a spare part from GCI).  Hubs connected via an 

IRB Segmenting Cable do not transmit or receive normal Ethernet traffic through the 

IRB.   

GCI supports this non-standard configuration, making special stacking cable 

available (see Models SRC-2 and SRC-4 in the Spare Parts Price List) to provide the 

flexibility to break apart managed stacks into multiple collision domains for higher 

performance, while still maintaining the advantages of one SNMP agent. 

 

Consider the case where it is desired to divide a managed stack into two 

segments and insert a local bridge to increase performance (see Figure 2.3.2a).   

Normally, it would be necessary to add another SNMP agent to maintain full 

management. However, using the special Segmenting cable option, it is possible to 

remove one standard IRB cable and replace it with an SRC cable.  This divides the stack