Rec. ITU-T G.783 (01/1994) … CHARACTERISTICS OF SYNCHRONOUS DIGITAL HIERARCHY (SDH) EQUIPMENT FUNCTIONAL BLOCKS
FOREWORD
CONTENTS
1 General
    1.1 Abbreviations
    1.2 Definitions
2 Basic functions
    2.1 SDH physical interface function (SPI)
        2.1.1 Signal flow from B to A
        2.1.2 Signal flow from A to B
    2.2 Regenerator section termination function (RST)
        2.2.1 Signal flow from C to B
        2.2.2 Signal flow from B to C
    2.3 Multiplex section termination function (MST)
        2.3.1 Signal flow from D to C
        2.3.2 Signal flow from C to D
    2.4 Multiplex section protection function (MSP)
        2.4.1 Signal flow from E to D
        2.4.2 Signal flow from D to E
        2.4.3 Switch initiation criteria
        2.4.4 Switching time
        2.4.5 Switch restoral
    2.5 Multiplex section adaptation function (MSA)
        2.5.1 Signal flow from F to E
        2.5.2 Signal flow from E to F
        2.5.3 Pointer processing function
    2.6 Higher order connection supervision (HCS)
        2.6.1 Signal flow from F to G (HPOM function)
        2.6.2 Signal flow from G to F (HUG function)
    2.7 Higher order path connection function (HPC-n)
        2.7.1 Signal flow
        2.7.2 CM configuration examples
    2.8 Higher order path termination function (HPT-n)
        2.8.1 Signal flow from H to G
        2.8.2 Signal flow from G to H
    2.9 Higher order path adaptation function (HPA-m, HPA-n)
        2.9.1 Signal flow from J to H
        2.9.2 Signal flow from H to J
    2.10 Lower order connection supervision (LCS-m)
        2.10.1 Signal flow from J to K (LPOM function)
        2.10.2 Signal flow from K to J (LUG function)
    2.11 Lower order path connection function (LPC-m)
        2.11.1 Signal flow
        2.11.2 CM configuration examples
    2.12 Lower order path termination function (LPT-m)
        2.12.1 Path OH at levels 1 and 2
        2.12.2 Path overhead at level 3
    2.13 Lower order path adaptation functions (LPA-m, LPA-n)
        2.13.1 Signal flow from M to L or H
        2.13.2 Signal flow from L or H to M
    2.14 PDH physical interface (PPI) function
        2.14.1 Signal flow from M to tributary interface
        2.14.2 Signal flow from tributary interface to M
3 Compound functions
    3.1 Transport terminal function (TTF)
    3.2 Higher order interface (HOI)
    3.3 Lower order interface (LOI)
    3.4 Higher order assembler (HOA)
4 Synchronous equipment management function
    4.1 Information flow across the S reference points
    4.2 Filter functions
    4.2.1 One second filters
    4.2.2 Failure filter
    4.2.3 ES, SES filter
5 Timing functions
    5.1 Synchronous equipment timing source function
    5.2 Synchronous equipment timing physical interface (SETPI) function
    5.2.1 Signal flow from SETS to synchronization interface
    5.2.2 Signal flow from synchronization interface to SETS
6 Specification of jitter and wander
    6.1 STM-N interfaces
        6.1.1 Input jitter and wander tolerance
        6.1.2 Output jitter and wander generation
        6.1.3 Jitter and wander transfer
        6.1.4 Transfer of wander encoded in AU and TU pointer adjustments
    6.2 G.703 interfaces
        6.2.1 Input jitter and wander tolerance
        6.2.2 Jitter and wander transfer
        6.2.3 Jitter and wander generation
7 Overhead access function
Annex A … Multiplex section protection (MSP) protocol, commands and operation
A.1 MSP protocol
A.1.1 K1 byte
A.1.2 K1 byte generation rules
A.1.3 Revertive/non-revertive modes
A.1.4 K2 byte
A.1.5 K2 byte generation rules
A.1.6 Control of the bridge
A.1.7 Control of the selector
A.1.8 Transmission and acceptance of MSP bytes
A.2 MSP commands
A.2.1 Switch commands
A.3 Switch operation
A.3.1 1 : n bi-directional switching