An IS auditor's primary concern would be whether the recovery site devices can handle the storage requirements. The storage requirements are determined by the amount and type of data that needs to be backed up and restored in case of a disaster at the primary data center. The recovery site devices should have enough capacity, performance, reliability, and compatibility to meet these requirements.
If the recovery site devices cannot handle the storage requirements, then there is a risk that some data may not be backed up properly or may not be available for recovery when needed. This could result in data loss, corruption, or inconsistency, which could affect the business continuity and integrity of the organization.
Therefore, an IS auditor should verify that:
* The recovery site devices have sufficient storage space to accommodate all the data that needs to be backed up from the primary data center.
* The recovery site devices have adequate bandwidth and speed to transfer and access data efficiently and effectively.
* The recovery site devices have appropriate security features and controls to protect data from unauthorized access or modification.
* The recovery site devices are compatible with the primary data center devices in terms of hardware, software, format, and protocol.
References:
* 10: What Is a Disaster Recovery Site? Hot, Cold & Warm Site
* 11: Disaster recovery site - What is the ideal distance to mitigate risks? - Advisera
* 12: Offsite Data Backup Storage vs Disaster Recovery (DR) - LINBIT

The best control to minimize the risk of unauthorized access to lost company-owned mobile devices is device encryption. Device encryption is a process that transforms data on a device into an unreadable format using a cryptographic key. Device encryption protects the data stored on the device from being accessed by unauthorized parties, even if they bypass the password or PIN protection. Device encryption can also prevent data leakage if the device is disposed of or recycled without proper data sanitization. Password or PIN protection is a basic control that prevents unauthorized access to the device by requiring a secret code or pattern to unlock it. However, password or PIN protection can be easily compromised by brute force attacks, shoulder surfing, or social engineering. Device tracking software is a tool that allows the device owner or administrator to locate, lock, or wipe the device remotely in case of loss or theft. However, device tracking software depends on the device's network connectivity and GPS functionality, which may not be available or reliable in some situations. Periodic backup is a process that copies the data from the device to another storage location for recovery purposes. Periodic backup can help restore the data in case of loss or damage of the device, but it does not prevent unauthorized access to the data on the device itself. References: CISA Review Manual (Digital Version), Chapter 5: Protection of Information Assets, Section 5.4: Mobile Devices

The IS auditor's primary concern when an organization has recently implemented a Voice-over IP (VoIP) communication system is a single point of failure for both voice and data communications. VoIP is a technology that allows voice communication over IP networks such as the internet. VoIP can offer benefits such as lower costs, higher flexibility, and better integration with other applications. However, VoIP also introduces risks such as dependency on network availability, performance, and security. If both voice and data communications share the same network infrastructure and devices, then a single point of failure can affect both services simultaneously and cause significant disruption to business operations. Therefore, the IS auditor should evaluate the availability and redundancy of the network components and devices that support VoIP communication. The other options are not as critical as a single point of failure for both voice and data communications, as they do not pose a direct threat to business continuity. References: CISA Review Manual,
27th Edition, page 385