sonet 101

SONET Networking
Local Inter-Node Deployment Example
Figure 5-4 illustrates how SONET can penetrate the local inter-node network.
The encircled area is the urban core—an area that could deploy SONET first
because of growth in the core area, exhausted capacity in the current optical
channels, and T1 modernization programs. Here, SONET allows inter-node
trunking with room for further growth.
In the longer term, SONET deployment can expand to suburban and rural
switching nodes. Hub topologies become common as circuits are consolidated to
route towards the core area. SONET add/drop multiplexers are used along the
way to pick up or drop off traffic.
Long-Haul Deployment Example
Figure 5-5 depicts a typical SONET network for inter-exchange carrier applications.
A long-haul SONET network deploys an OC-n high-speed transport overlaying
an existing asynchronous network, using a 565 Mbps FOTS. The main
SONET network elements are the SONET add/drop multiplexer used in terminal
and repeater configuration and the SONET broadband cross-connect used for
traffic management.
51
SONET 101