Stateful traffic analysis identifies all packets in all connections related to an application or service. This typically involves Layer 4 in the OSI model – the transport layer – where the relationships of the packets are tracked as one TCP connection dynamically negotiates another TCP connection at a different ephemeral TCP port.
Compared to the stateless nature of Layer 2-3 traffic which only looks at each packet independently of the others, stateful traffic analysis requires more resources and processing power, and involves a whole different set of parameters.
Analyzing stateful traffic is essential for measuring the performance of devices tasked with handling TCP traffic such as firewalls, switches NAT routers and so on.
Xena’s Vulcan product line is used for stateful traffic generation and analysis up to 40Gbps.