Chapter 1: What you need to know about cloud computing - Iaas, Paas, SaaS

What’s inside a cloud?

Imagine you could easily pick out, which cloud telephony vendors you needed to speak to according to your hardware or software requirements, simply because you understood how the cloud was structured and the prime benefit each part presented.

It’s not impossible…

A previous blog gave a brief definition of cloud computing.  The next question to tackle is “What actually makes up the cloud”.  Once you have an understanding of cloud structure, it will be far easier for you to absorb, which cloud telephony players you need to talk to in order to replace different ‘in-house’ or ‘on-premise’ systems and equipment. 

Easy as one, two three? Or should that be IaaS, PaaS, CaaS?

A good way to view the cloud is to think of it being comprised of three distinct layers, each of which are essentially service levels – independently playing the role of the hardware and/or software you already have installed. 

1.    Central to any cloud is Infrastructure-as-a-Service (IaaS).  This relates to the physical infrastructure, which as far as end-users (perhaps you) are concerned, is abstracted to provide storage, networking and compute resources.  Examples would be Amazon EC2 and Rackspace

2.    A second level is Platform-as-a-Service (PaaS), which could be an operating system or computer language interpreter that enables bespoke applications to be written and deployed.  Example would be Google Voice, Aculab Cloud

3.    Finally, you have Software-as-a-Service (SaaS). You have probably had experience with applications of this type, which you may have purchased or even gained use of for free.  The key point is that these applications are accessed using your web browser.  Examples would be hotmail, Google Apps

It may help you to better understand each of these by exploring their role in relation to the benefits they provide.

So a cloud comprises of these three core services (there are many more ‘as-a-service’ acronyms, but let’s save those for another blog). Depending on your objectives and what computing resource you are looking to replace, it will be easier to identify the market players you should be talking to by the way they position themselves i.e., whether they are offering IaaS, PaaS or CaaS.

An important point to consider during your selection process is that services may be deployed in three different types of cloud - private, public or hybrid (a combination of public and private) cloud.  The different types and their benefits, will be explored in more detail in the next blog.

For further information on the different service elements contained in a cloud, the following links may offer a good starting point.

Top level http://gu.com/p/2hzjx

Top level with good further reading refs http://blogs.fasthosts.co.uk/2011/02/saas-paas-iaas-cloud-computing/