The section overhead (SOH) of a STM-1 signal is divided into two parts: the regenerator section overhead (RSOH) and the multiplex section overhead (MSOH). The overheads contain information from the transmission system itself, which is used for a wide range of management functions, such as monitoring transmission quality, detecting failures, managing alarms, data communication channels, service channels, etc.
the SEcTiOn ovErhEaD (SoH) of a stm-1 sigNAl is dIvidEd intO twO pARts: The REgEneRaTor section ovErhead (Rsoh) and thE muLtiPLEx seCtion oVerHead (mSoh). tHe oVErheadS conTain infOrMaTioN frOM THE t,ransmISsiOn systEM itsElf which is used fOr A wIDe Range of maNagemenT FuNctions, suCh as mONItoring tRAnsmiSsion quALiTY, detectinG fAilures, maNAging alarms, DaTa coMmUnicAtiOn chAnNeLs, SerViCe channELs, etc.