Which of the following is a purpose of capturing live network traffic?

Capturing live network traffic primarily serves the purpose of documenting communications for compliance. This is crucial in various industries where regulations require organizations to maintain records of data transmission, user activity, and communication flows. Such documentation can be vital for audits, investigations, and ensuring adherence to legal and regulatory standards. By monitoring and recording network traffic, organizations can demonstrate compliance with data protection laws, ensure the integrity of communications, and be prepared for potential legal scrutiny.

While the other options touch upon areas that may intersect with the analysis of network traffic, they are not the main reasons for capturing this data. Isolating faulty hardware typically involves diagnostics at a more physical or localized level rather than solely relying on traffic data. Replicating user activity pertains more to user simulation or behavioral analysis rather than documenting actual communications. Improving connection speeds is generally related to network optimization techniques rather than direct benefits of capturing network traffic itself.