CCITT Rec. G.709 – SYNCHRONOUS MULTIPLEXING STRUCTURE
1 Basic multiplexing structure
2 Mapping formats and multiplexing method
    2.1 Mapping and multiplexing up to STM-1
    2.2 STM-N multiplexing
    2.3 Maintenance signals
    2.4 Timing recovery
    2.5 Conceptual steps for STM-N assembly
3 Pointer
    3.1 AU pointer
    3.2 TU-3 pointers
    3.3 TU-1/TU-2 pointers
    3.4 Pointer operation for STM-1 concatenation
4 Path overhead
    4.1 VC-1/VC-2 path overhead
    4.2 VC-3/VC-4 path overhead
5 Mapping of tributaries into VCs
    5.1 Mapping of tributaries into VC-4
    5.2 Mapping of tributaries into VC-32
    5.3 Mapping of tributaries into VC-31
    5.4 Mapping of tributaries into VC-22
    5.5 Mapping of tributaries into VC-21
    5.6 Mapping of tributaries into VC-12
    5.7 Mapping of tributaries into VC-11
    5.8 Floating and locked mode conversion