Indonesian customer behavior is changing along with the adoption of the Fourth Generation (4G). On the other hand, the existence of the Over-The-Top (OTT) service has replaced the Second Generation (2G) technology which has been the operator's main income. This study analyzed the sustainability of 2G technology by collecting data including the number of the subscriber, handset capability distribution, revenue distribution, and traffic distribution from one of Mobile Network Operators (MNOs). This study observed the market share and market growth of the 2G, 3G, and 4G based on revenue and traffic distribution using the Boston Consulting Group (BCG) matrix for making technological decisions. The result showed that the 2G is classified as Dogs and has been in the decline phase of the technology life cycle. From a technical point of view, we forecasted and showed that the 2G traffic decreases following S-Curve model and remaining only 2% of the traffic in December 2019. This suggested MNO and regulator to prepare some procedures to terminate the 2G. Moreover, we proposed a strategy for the 2G termination based on busy hour traffic and spectrum re-farming that could be implemented in a cell.