The views, opinions and concepts expressed are those by the author of this entry only and do not necessary conform to industry descriptions or best practises.

Shortened Names
INFRASTRUCTURE-AS-A-SERVICE – iaas
ACCESS CONTROL LIST – acl
VIRTUAL NETWORKS – vlan
VIRTUAL MACHINE – vm
DEMILITARIZED ZONE – dmz

Infrastructure as a Service (IaaS) enables a tenant i.e you the reader of this blog post to purchase an allocated amount of computing, storage and networking resources from a (Managed) ISP. You then have the capability to assign or carve up these IaaS resources to create your own virtual datacentre (VDC) through a safe, secure web-based management console.

The IaaS management consoles typically will offer and allow the tenant the ability to create there own ACL, VLANs, placement of virtual machines (VM) within your VDC, building VMs from generic templates maintained by the (Managed) ISP and so much more.

The IaaS resources provided by the (Managed) ISP should be fully managed e.g border routers, core switches, hosts and mgmt. infrastructure of the IaaS platform and hosted within a highly-available N+1 data centre so that in the unlikely event of a logical or hardware failure your VDC environment will not be compromised or should automatically failover to onto alternative infrastructure and be rebooted and return to an online and active status within a few minutes.

What is the benefit of IaaS? You don’t have to secure any capital investment to acquire the nesscary hardware to support your existing organisations growth demands or if your a start-up it eases your cash flow requirements as you only pay for the computing, storage and networking resources that you need effectively require month by month.

Today IaaS is also referred to by some as a Software-Defined Data Centre.

Examples of IaaS Platforms
http://www.citrix.com/products/cloudplatform/overview.html.
http://cloudstack.apache.org/.
http://www.vmware.com/uk/products/vcloud-director.