Which report is most suitable for an IS auditor to verify compliance with a service level agreement by an ISP?

The most suitable report for an IS auditor to verify compliance with a service level agreement (SLA) by an Internet Service Provider (ISP) is the downtime reports generated by the enterprise.

This type of report directly reflects the performance and availability of services as experienced by the business. An SLA often includes specific commitments regarding uptime and downtime allowances. By examining the downtime reports generated by the enterprise, an auditor can assess whether the ISP met the agreed-upon service levels concerning service availability.

These reports are crucial because they offer a firsthand account of how the services are performing in real-world conditions and allow for an evaluation against the SLA terms. If the downtime exceeds the limits defined in the SLA, the enterprise has a basis for discussions with the ISP regarding non-compliance.

While downtime reports generated by the ISP contain valuable information, they might not fully capture the context from the enterprise's perspective, where the actual impact of downtime on services is experienced. Similarly, utilization reports of failover services or bandwidth utilization might not directly correlate with SLA performance metrics. Therefore, the enterprise's downtime reports are the most relevant for compliance verification with the SLA.