Cloud Computing Service Models
Cloud computing is a convenient way of on-demand network access to shared pool of resources such as networks, storages, servers, applications, and services which can be instantly provisioned and released as per consumer requirement.
Cloud Computing includes 3 service models:
- IAAS (Infrastructure As A Service) – Host
In this service model, consumer acquires required resources available in the Cloud infra and chooses to deploy and managed the acquired resources as per his/organization requirement.
Consumer will not have control over the Cloud Infra but the applications alone which he has acquired from cloud.
This leads to limitation with high availability as the acquired resources needs to be managed and controlled as and when there is any unexpected outages or platforms updates at cloud infra level.
- PaaS (Platform As A Service) – Build
In this service model, Consumer will deploy his acquired resources on to the cloud infra itself and let cloud infra manage his acquired resources.
By this Consumer will not have control over cloud infra as we all his acquired resources.
This model is highly available as the Cloud infra will take ownership of providing alternate solution due to unexpected outages.
- SaaS (Software As A Service) – Consumer
In this service model, Consumers are provisioned to utilize the available pre-defined configuration resources as they are available in the cloud infra without acquiring them.
The resources /applications are accessible through various client devices.
Consumer will not have control over cloud infra nor on resources. This type of model eliminates capital expense of buying hardware or software as they are set to run on on-site datacenters.
Windows Azure Virtual Private Network Models
Windows azure vpn model are of 2 types:
- Site – to – Site VPN:
- Internal organization should have RRAS or physical gateway installed on one VM client.
This will enable all clients in local site to access on clients/resources in cloud virtual network.
Internal organization should also requires IPSec secured connection for encryption services. This also enables in Hardware based VPN on own organization.
- On Virtual network cloud we need to install Azure gateway on one of the VM client.
- Point – to – Site virtual networks:
- Specific vms or more than one VMs on the internal organization will be connecting to cloud based virtual network but not all VMs on the internal org.
- Hence this is not network to network connectivity as this is selective VMs
- Needs creation of Root certificate for point – to – point vpn set up.