<![CDATA[Internet service quality is determined not only by connection speed and stability but also by the capability of network protocols to support traffic management, authentication, and communication security. However, customers generally have limited understanding of these technical aspects and tend to evaluate services based on the outcomes they directly experience, while studies linking network protocol implementation to customer satisfaction remain limited. This study aims to analyze the effects of network protocol implementation on customer satisfaction, service quality, and service security, as well as the effects of service quality and service security on customer satisfaction at Gmedia and Time Excelindo in Yogyakarta. A mixed-methods approach was employed using quantitative data from 150 respondents and qualitative data obtained through interviews with two representatives of the service providers and ten customers. The quantitative data were analyzed using Partial Least Squares Structural Equation Modeling with SmartPLS, while the interview data were analyzed thematically. The results indicate that network protocol implementation does not have a statistically significant direct effect on customer satisfaction (t = 0.690; p = 0.490), but has significant effects on service quality (t = 12.959; p < 0.001) and service security (t = 16.254; p < 0.001). Service quality has a significant effect on customer satisfaction (t = 4.652; p < 0.001), as does service security (t = 2.203; p = 0.028). The qualitative findings show that customers place greater emphasis on access speed, connection stability, data security, and responsiveness in handling service disruptions than on the specific network protocols used.]]>
