The book "Capacity Management for Packet-Switched Networks" by Linda de Jonge provides a comprehensive analysis of the sizing of network connections required for various communication services such as email, file transfers, web browsing, online chat, IP telephony, and real-time video. In today's digital world, it is crucial that the capacities of network connections are adequately sized to avoid delays in data traffic and ensure high service quality. The focus is on examining the requirements for link capacity, particularly regarding the different access rates of corporate users compared to consumers. The book develops a model that allows for the determination of the necessary capacity to meet specific quality requirements related to delays and throughput. It also thoroughly addresses the impact of corporate usage on the required link capacity.