scope:

This report covers the comparison of transport rates; multiplexing structure; payload mappings; Operations, Administration, Management and Provisioning (OAM&P); and interworking issues.

Purpose

SONET and SDH are compatible, but not identical, digital hierarchies. Both define similar sets of overheads and functions, however, there are differences in the usage of the two overhead structures. The purpose of this technical report is to identify the areas where SONET and SDH differ

- in overhead/format definition

- in usage/interpretation of overheads

Once the differences have been clearly identified, it will be possible to assess the appropriate actions to be taken to insure smooth interworking between networks based on the two hierarchies. The Table 8 of this document is divided into two parts 8a and 8b. The first part, 8a, contains the detailed descriptions/definitions of the bytes as found in the standards documents as well as differences between SONET and SDH. The second part, 8b, documents the performance information as found in standards documents and highlights differences between SONET/SDH. In addition, the interworking information is grouped by SONET/SDH layers: Section, Line, and Path.