Physical server allocation is not a characteristic of IaaS, as IaaS provides virtualized resources that can be dynamically allocated and scaled.

The primary responsibility of an IaaS provider is to manage and maintain the hardware infrastructure, including servers, storage, and network components.

Hypervisor-based virtualization is widely used in IaaS environments to create multiple virtual machines (VMs) on a single physical server.

A hypervisor performs all of the mentioned tasks in an IaaS environment, including managing VM resources, isolating VMs, and providing a platform for running applications.

ISO/IEC 17789 is the international standard that defines the interoperability of cloud services, including IaaS.

NIST SP 800-145 provides guidelines and recommendations for implementing security controls in cloud environments, including IaaS.

RFC 4271 defines the Border Gateway Protocol (BGP) version 4, which is widely used for routing in IaaS networks.

IEEE 802.1Q defines the standard for virtual LANs (VLANs), which are used to segment IaaS networks into logical subnetworks.

Managed cloud is not a type of IaaS service model. It refers to a cloud service where the provider manages and maintains the infrastructure and applications on behalf of the customer.

Public cloud IaaS services offer reduced capital expenditure as customers pay only for the resources they use, eliminating the need for upfront investments in hardware and infrastructure.

IBM Cloud is not a key player in the IaaS market. The dominant players in this market are Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP).

The Cloud Security Alliance (CSA) focuses on developing security best practices, guidance, and standards for cloud computing, including IaaS.

Physical server failures are not a common security concern in IaaS environments, as IaaS providers manage and maintain the underlying hardware infrastructure.

A service-level agreement (SLA) in IaaS defines the performance and availability guarantees provided by the cloud service provider to the customer.

Cost per gigabyte is not a common metric used to measure IaaS performance. It is a pricing metric that reflects the cost of storing data in the cloud.