Architecture of SONET consists signals, devices, and connections.

1. SONET Devices

Figure 1 shows a simple link using SONET devices. SONET transmission relies on three basic devices: STS multiplexers/demultiplexers, re-generators, add/drop multiplexers and terminals.

STS Multiplexer/Demultiplexer: STS multiplexers/demultiplexers mark the beginning points and endpoints of a SONET link. They provide …