Abtsrcat A maximum likelihood estimator (MLE), a consistent asymp- totically normal (CAN) estimator and asymptotic condence limits for the expected number of entities in the system (LS) in a two service point tandem queue with at most one entity in between the service points and busy service point 1 are obtained. Further, for a three service point tandem queue with busy service points 1 and 2 and at most one entity in between the last two service points, the MLE, CAN estimator and asymptotic confidence limits for LS are obtained.