FDDINetwork Topologies 75
7
Advantages
Dual-homing offers the same advantages as a standalone concentrator,
described on page 72. It also offersimproved resistance against cable faults and
concentrator failure.
Disadvantages
The number of stations that can be attached to the concentrator is limited by
the number of M-ports, which is typically between 2 and 32. Since each
dual-homed station requires two M-ports, only a limited number of stations
can be connected in this way.
The dual-homing configuration requires a minimum of two concentrators,
which are more expensive than single-attached or dual-attached stations.
Treeof Concentrators
The tree of concentrators is an incremental expansion of the standalone
concentrator topology,described on page 72. Two or more concentrators are
connected in a hierarchical topology,with one concentrator designated as the
root of the tree, as shown in Figure7-5. This topology is typically used to
connect a large number of stations within a single building or office.