SONET/SDH Architecture

The SONET/SDH architecture identifies three different layers, each of which corresponds to one level of communication between SONET/SDH equipment. The layers are as follows, starting with the lowest:

  • The regenerator section, or section layer

  • The multiplex section, or line layer

  • The path layer

Figure A-3 shows the three SONET/SDH layers.

Figure A-3. SONET and SDH Layers
[View full size image]

As shown in Figures A-1 and A-2, each of these layers in turn has its own overhead (header). The transport overhead (TOH) of a SONET/SDH frame is mainly subdivided into two parts that contain the section overhead (SOH) and the line overhead ...

Get Metro Ethernet now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial