Network Design
The Collapsed Backbone
It is also possible to run cables from a central point, often a network management office or central wiring closet, out to each workgroup network and back. These cabling runs are then terminated at a central point such as a patch panel. The patch panel ports for each of the cable runs can then be connected to one another using jumper cables. As long as technology restrictions are not exceeded, chains and rings of workgroup networks can be created.
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Figure 5-6. Collapsed Backbone
Having the individual cable runs of the backbone connected to one another at a single point can make this configuration more expensive than the distributed backbone, however the added configuration and control options provided by the collapsed backbone often outweighs the associated costs.
•Connectivity Requirements - The collapsed backbone implementation brings all cables of the backbone to a central point, and the requirements of the Token Ring and FDDI technologies for an unbroken ring still apply.
•Ease of Expandability - Since the cables of the collapsed backbone originate from a patch panel in one location, adding new cable runs to accommodate new workgroups or to bypass outmoded ones is a simple matter of changing a few jumper cables. If the network cabling was planned far enough in advance, the facility cabling required to add new workgroups to the backbone network may be already in place, requiring only a set of jumper cables and a short amount of time to connect. The use of a collapsed backbone can ease the transition from a backbone network with no controlling hardware to a device collapsed backbone in the future.
The Workgroup in the Larger Network |
