Bob.

In the scenario described, Bob collected data that summarizes a conversation between two network devices. This type of data typically includes the source and destination IP addresses and ports, the duration of the conversation, and the information exchanged during the session. This aligns with the definition of session data, which is a type of network-based evidence that provides an overview of communication sessions between devices without including the actual content of the data packets.

References: The EC-Council Certified Security Specialist (E|CSS) materials cover various types of network-based evidence as part of the Network Defense, Ethical Hacking, and Digital Forensics modules. Session data is specifically discussed in the context of network security monitoring and analysis, where it is used to track and summarize network interactions.