Cabletron Systems switches User Manual

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Network Design
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The Workgroup in the Larger Network
Simplified Troubleshooting - Workgroups can be bypassed by simply 
reconfiguring a single patch panel. This can easily isolate a problem segment 
for troubleshooting, and keeps the backbone network from being kept in a 
fault condition.
Moderate Control - The isolation of workgroups and the reorganization of the 
backbone network is simplified with the collapsed backbone, but the system 
does not incorporate any management features beyond the physical 
connections of facility cabling. For advanced and detailed network control 
operations, the device collapsed backbone (discussed below) is superior to the 
collapsed backbone alone.
Devices as Backbones
Once a collapsed backbone has been designed, it is a simple matter to connect the 
multiple backbone cables together through a device. Often this device is a 
multiport router, network switch, or a modular chassis. The use of a device of this 
type to make the connections between workgroups greatly increases the control 
that Network Managers have over the network, and may improve performance 
by streamlining the communications between networks. 
Figure 5-7. Device Collapsed Backbone
The device collapsed backbone is the most expensive backbone because of the 
added cost of sophisticated, high-performance hardware to the costs of a 
collapsed backbone cabling layout. In many cases, the additional control and 
functionality of the device collapsed backbone configuration are so valuable that 
the cost is well worth it.
Connectivity Requirements - The device collapsed backbone implementation 
brings all cables of the backbone to a single device, which takes care of the 
interconnection issues.
Ease of Expandability - As all the workgroups of the network are connected 
through the backbone device, the expandability of the network is limited by 
the amount of expandability that the device is capable of. As with the design 
of facility cabling, planning for future needs will go a long way toward 
reducing future expenses and possibly avoiding a costly replacement upgrade.
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Ethernet Switch
2094n12