sonet 101

SONET Networking
DEPLOYMENT OF SONET IN THE ACCESS NETWORK
As shown in Figures 5-6 and 5-7, SONET can be deployed in the access network,
particularly where new fiber is being installed and/or existing routes are being
exhausted, to provide new networking capabilities and transport of new services.
Different application scenarios are described below:
Simple Point-to-Point
A point-to-point application is relatively simple to implement. Instead of a pairgain
link such as twisted pair copper, fiber is used to connect a control terminal
from a switching node switch to a remote terminal. SONET will transport multiple
DS-1s to the CSA with plenty of room for growth. The overhead channel
links all systems together for integrated OAM&P.
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Add/Drop Application
The SONET system transports traffic from the switching node to a terminal at a
CSA or customer premises location. To pick up or drop off additional traffic,
intermediate SONET add/drop multiplexers are used for CSAs located along the
way. ADMs could also be connected in a closed OC-n loop to provide a survivable
ring topology.