Applications
Issue 8.0 July 2002
2-7
Folded rings also provide flexibility and can help evolve networks into full ring
applications. Figure 2-3 shows an example of a folded ring that evolves into a full
ring application. In many cases, a network starts out as a folded ring because of
short-term service needs between some of the nodes. Then the folded ring
evolves into a full ring later when service and fiber facilities to other nodes in the
network are needed. It is easier to evolve a folded ring into a full-ring application if
a folded ring is used in the nodes that have this short-term service need. Folded
rings have upgrade, operational, and self-healing advantages over other
applications for this type of evolution.
Figure 2-3. Folded Rings Evolving to Full Ring Networks
Site A
FT-2000*
Site C
FT-2000*
Site B
FT-2000*
FT-2000*
Present
Site A
FT-2000*
Site C
FT-2000*
Site B
FT-2000*
Future
Site D
FT-2000*
* FT-2000 OC-48 Add/Drop-Rings Terminal