FDDINetwork Topologies 77
7
Disadvantages
This configuration suffers from the same disadvantages as the standalone
concentrator,described on page 72. The number of stations connected to each
concentrator is limited by the number of M-ports, and the loss of a
concentrator takes down all of the stations to which it is attached.
Ring of Trees
The ring of trees is a derivative of the tree of concentrators topology described
on page 75. The rootconcentrator is replaced by a dual-ring to which
dual-attached concentrators are connected, as shown in Figure7-6. This
topology is ideal for connecting a large number of stations in a campus or
multiple-building network.
Figure7-6 Ring of Trees
Tree of concentrators (1) Tree of concentrators (2)
SAS SAS SAS SAS SAS SAS SAS SAS
DAC DAC DAC DAC
DAC
DAC DAC
DAC
SAS SAS SAS SAS
Horizontal distribution frame
Intermediate distribution frame
Main distribution frame