Cloud Network

Cloud

1. Definition of cloud computing by US national institure of standards and technology (NIST)
   1. On-demand self-service: the IT consumer chooses when to start and stop using the service, without any diret interation with the provider of the serivce.
   2. Broad network access: The service must be available from many types of devices and over many types of networks .
   3. Resource pooling: The provider creates a pool of resource and dynamically allocate resource form that pool for each new request
   4. Rapid elasticity: to the consumer, the resource pool appears to be unlimited and the requests for new service are filled quickly.
   5. Measured service: the provider can measure the usage and report that usage to the consumer both transparency and for billing.
2. Private cloud
   1. Cloud service catalog: catalog of application vms
3. Public cloud
   1. Advantage
      1. Agility – An enterprise can get started using public cloud without having to wait to order a private WAN conneciton to the cloud provider because cloud providers support internet
      2. Migration: an enterprise can switch its workload from one cloud provider to another more easily
      3. Distributed users: The enterprise’s users are distributed and connect to the internet with their devices
   2. Disadvantage
      1. Seccurity: The internet is less secure than private WAN
      2. Capacity: large load for migration
      3. QoS: no Qos
      4. No WAN SLA: ISP don’t provide SLA for WAN performance and availability.
   3. Intercloud exchange – private WAN with publich cloud migration less on PE to CE side.

1. Virtual network funciton (VNF) traditional networking device that consuer can choose to use in cloudl