A comprehensive study guide to the architecture, hierarchy, and framing of SONET (ANSI T1.105).
Standardized digital hierarchy for fiber optics.
Unlike PDH (Plesiochronous), SONET uses a single master clock source. All network elements are synchronized, allowing direct access to low-speed tributaries without demultiplexing the entire stream.
Designed specifically for fiber optic transmission. It defines optical carrier (OC) levels and the electrical equivalent (STS) for standardizing interfaces between equipment from different vendors.
Built-in overhead bytes allow for robust Operations, Administration, and Maintenance (OAM). This enables performance monitoring, fault detection, and remote configuration without service interruption.
The basic building block of SONET.
Multiplexing lower-order signals into higher-order streams.
Click on any network element in the diagram to understand its function within the SONET ring or mesh architecture.
Formula: Rate = STS Level × 51.84 Mbps
Note: Valid levels are typically 1, 3, 12, 48, 192 (powers of 4 multiples of 3), though the slider shows continuous progression for estimation.