This document provides an overview of Synchronous Digital Hierarchy (SDH) represented in images.
There are no specific prerequisites for this document.
This document is not restricted to specific software and hardware versions.
Refer to Cisco Technical Tips Conventions for more information on document conventions.
These sections provide an overview of SDH in graphical format.
This diagram shows what an SDH link looks like.
This diagram shows the Synchronous Transport Module level 1 (STM1) frame structure.
This diagram shows what the STM1 Section Overhead (SOH) looks like.
This diagram looks at VC4 Concatenation.
This diagram displays the SDH hierarchy.
This diagram shows how SDH maintenance interactions look.
This table looks at what the alarms mean and their detection criteria.
These diagrams provide a description of all the bytes from STM1 SOH, High Order Path Overhead (HO-POH) and Low Order Path Overhead (LO-POH).