Frame Loss Ratio (FLR) is a key performance metric that can help service providers determine whether their Carrier Ethernet (CE) services comply with a Service Level Specification (SLS) as specified in MEF 10.4. Service providers can measure adherence to an FLR performance objective in an SLS using one of two Ethernet frame loss measurement tools specified in ITU-T Y.1731: Ethernet Synthetic Loss Measurement (ETH-SLM) or Ethernet Loss Measurement (ETH-LM). As a companion document to the Nokia white paper “Improving service assurance in packet transport networks”, this technical white paper aims to compare the measurement time between ETH-SLM and ETH-LM. To measure FLR with confidence and sufficient accuracy, the service provider must decide how many samples to collect and for how long. This white paper provides insights that can help service providers determine the minimum sample size they need to measure FLR as accurately as possible. It also compares the measurement intervals required to achieve a desired FLR accuracy using ETH-SLM and ETH-LM.