Mean response time for single user and mean waiting time for multiple users are important measures of Quality of Service (QoS) in accessing a web server. This paper presents analytical models to find the mean response time and the mean waiting time for web service using Hyper Text Transfer Protocol (HTTP) over Stream Control Transmission Protocol (SCTP). The proposed response and waiting time model assumes the multiple packet losses and a narrowband network, where fast retransmission is not possible due to small window. The authors' experiments validate the accuracy of the proposed model. It is shown that the differences between the results from the model and those from the experiments are very small on average.