Private cloud: This option is usually designed and managed by an IT department within an enterprise or organization. This option offers internally hosted services behind a corporate firewall to specific authorized people. This "internal" or "corporate" cloud option appeals to enterprises that want to retain more control over their data than they can in a cloud service hosted by a third-party.
Hybrid cloud: This option combines public and private cloud options and allows customers to manage some resources in-house and some externally through a third-party cloud provider. Many enterprises choose this option to keep sensitive data under their own control for security purposes.
Cloud computing services lead to secondary markets
Cloud computing services include the following subsets, with more options expected over time:
· Software as a Service (SaaS): Applications are delivered over the network (usually the Internet) on a subscription and on-demand basis. Example: Software.com. This market is still in the early development stages with no clear market winners, although traditional telecom providers have less expertise to offer in this market than IT service providers.
· Platform as a Service (PaaS): Operating systems, software development frameworks and associated services delivered over the Internet without downloads or installation. PaaS also supplies hosted development and testing environments for developing APIs.
· Infrastructure as a Service (IaaS): Network, computing power and storage delivered to customers on a usage basis. Many telecom service providers are positioning themselves in this segment. Outside traditional telecom, Accenture formed an alliance with Cisco to enter the IaaS market. Market examples include: Verizon Business's Computing as a Service (CaaS), BT's Virtual Data Centre, AT&T Synaptic Hosting, and Amazon EC2.
· XaaS: A collective term that can stand for anything or Everything as a Service, including the network and storage. For example, Security as a Service is another SaaS cloud service.
There is a disconnect between the hype surrounding the uptake of cloud-based services and the number of enterprises actually embracing the new business model. To make enterprises comfortable enough to make the move, cloud providers must be ready to address any issue that enterprises see as negative compared with owning and managing their own hardware, software and network facilities.