Virtualization has become an essential component of modern applications, providing flexibility and scalability at a manageable cost. This thesis examines network performance in virtualized Linux environments, with particular focus on the impact of CPU allocation on achievable throughput and the overhead introduced by system and virtualization layers. By analyzing different communication scenarios between hosts and virtual machines, the study explores how resource constraints affect network performance. The collected data are further examined through a targeted analysis of CPU behavior and workload distribution across both host and virtualized contexts. The main objective is to quantify overhead in terms of CPU utilization and network performance, identifying conditions under which performance parameters remain within predictable ranges and revealing any deviations that might impact throughput.