Estimating cell transfer delay in ATM networks using in-service monitoring methods

Cell transfer delay (CTD) is a performance parameter of the ATM layer. Monitoring CTD requires procedures for in-service measurement or estimation and for gaining statistics of the delay distribution. This paper discusses the definition and origin of CTD, and looks at basic measurement techniques based on operation and maintenance (OAM) performance monitoring functions. It presents a method for estimating CTD, which does not rely on the availability of synchronized clocks at the measurement points. This method is based on a least-square regression analysis which estimates the time and frequency offset of the remote clock