The usage of stateful inspection firewalls are advantageous to the majority of enterprises. These units act as a more thorough gateway between computers, other assets housed behind the firewall, and resources located outside the company. Additionally, they can successfully protect network devices from specific threats like DoS. State-aware devices track whether a packet is a part of an active TCP or another network session in addition to inspecting each package. While providing better security than either circuit monitoring or packet filtering by themselves, this has a more significant negative impact on network performance. Another variation on stateful inspection is the multilayer inspection firewall, which considers the flow of transactions across many protocol layers of the seven-layer Open Systems Interconnection (OSI) model.