What is Cloud Computing virtualization Cloud Networking Cloud networking (and Cloud based networking) is a term describing the access of networking resources from a centralized third-party provider using Wide Area Networking (WAN) or Internet-based access technologies. Cloud networking is related the concept of cloud computing, in which centralized computing resources are shared for customers or clients. In cloud networking, the network can be shared as well as the computing resources. It has spurred a trend of pushing more network management functions into the cloud, so that fewer customer devices are needed to manage the network.

1. What is Cloud Computing
In the simplest terms, cloud computing means storing and accessing data and
programs over the Internet instead of your computer's hard drive. The cloud is just a
metaphor for the Internet
Benefits of Cloud Computing
Increased scalability:
• The cloud can dynamically and instantly provide the computing
resources.
• This provision can be on demand or as per user configuration.
• Similarly these IT resources can be released automatically or
manually with the decrease in processing demand.
• This dynamic scalability avoids the over-provisioning and under-
provisioning and the associated disadvantages.
Availability:
• The availability of IT resources sometimes can be referred to profit
and customer retention.
• If an IT resource becomes unavailable (such as a database dealing
with clients’ orders) then this may result in customer dissatisfaction
and loss of business.
Reliability:
• The reliability of IT resources is very important for continual
business data processing and response time.
• The failure of any IT resource can be cause the collapse the IT
system. For example failure of the Ethernet switch may crash a
distributed application.
• The modular structure and resource redundancyin cloud increases
the availability and reliability.
• Cloud, on the other hand provides a guaranteed level of availability
and reliability through a legal agreement called service level
agreement (SLA) between the cloud provider and cloud user.
• The recoverytime after failure is the added penalty. It is the time
when the system remains unavailable.
• The modular structure and resource redundancyin cloud increases
the availability and reliability. It also improves the recoverytime.
Virtualization
• Virtualization: It is a technology used to enhance the utilization of
computing resources.

2. • A single hardware machine is multiplexed among multiple virtual
machines (VMs).
• A software based virtual machine monitor/manager (VMM) or
hypervisor is a program that manages the hardware resources for
the VMs and also keeps each VM from disrupting other VMs.
Virtualization implementation levels:
1. Instruction Set Architecture (ISA) level:Executing legacy code over new machines
using ISA emulator tool such as an interpreter which translate one instruction of source
code into corresponding instruction of the target machine.
2. Hardware Abstraction level:
The hardware components (CPU, RAM, Disk, NIC) of a physical system are virtualized
and shared among virtual machines using Virtual Machine Monitor (VMM) tool or
hypervisor which performs as abstraction layer.
4. Library support level:
The API calls for hardware acceleration such as vCUDAstubs for graphic processing
units (GPUs) are available at VM level.
5. Application level:
An application acts as a VM through wrapping of application in an abstraction layer
which isolates it from OS and other applications. Another type is using virtualization
layer as programming environment e.g; Java Virtual Machine (JVM).
Hypervisor transforms the physical hardware into virtual hardware.
VM Architectures
There are three classes of VM architectures.
1. Hypervisor Architecture
2. Full-virtualization Architecture
3. Para-virtualization Architecture
4. Hypervisor Architecture
It is the hardware level virtualization. Also called the bare-metal virtualization
The hypervisor sits between the hardware and the VMs and manages the VMs.
Example: Xen, VMware
Full Virtualization:
The guest operating system (OS) or the VM’s OS does not know that it is installed on a
VM.
The Virtualization layer manages the hardware acceleration. For example VMware

3. The virtualization layer can be installed on hardware or on host’s OS.
Some of the instructions of a gust VM are directly run on hardware to enhance the
performance.
Para-virtualization Architecture:
The guest OS is modified to comply with virtualization layer. All calls for hardware
acceleration are handled by virtualization layer.
For example: KVM
Security law
Cloud provider:
The organization that provides the IT resources.
Responsible for providing IT resources as per SLA.
Cloud consumer:
The organization or individual who has contracted with cloud provider to lease/rent the
cloud IT-resources through user interface and/or through software API calls.
Cloud Resource Administrator: This role is responsible for administering the cloud resources
(including cloud services).
Cloud Auditor: Provides an unbiased assessment of trust building features of the cloud. These
include the security, privacy impact and performance of the cloud. The cloud consumer may rely
upon the cloud audit report for choosing a cloud.
Cloud Broker: A party that provides mediation services to cloud providers (seller) and cloud
consumers (buyer) for the purchasing of cloud services.
Organizational boundary: This is a boundary of ownership ad governance of IT assets of an
organization. Similarly, the cloud has its organizational boundary.
Trust boundary: When an organization takes the role of cloud consumer, then it has to extend
its trust boundary to include the cloud resources.
A trust boundary represents a border around trusted IT-resources.

4. Cloud Networking
Cloud networking (and Cloud based networking) is a term describing the access of networking
resources from a centralized third-party provider using Wide Area Networking (WAN) or
Internet-based access technologies.
Cloud networking is related the concept of cloud computing, in which centralized computing
resources are shared for customers or clients. In cloud networking, the network can be shared
as well as the computing resources. It has spurred a trend of pushing more network
management functions into the cloud, so that fewer customer devices are needed to manage
the network.
LAN Cloud
Cloud networking is a form of Software Defined Networking (SDN) technology, in which
groups of networking switches and access devices can deploy over the wide area as shared,
virtual resources. Other terms that describe this shift include Software-Defined WAN (SD-WAN)
and Cloud WAN.
Cloud WAN
Cloud networking (and Cloud based networking) is a term describing the access
of networking resources from a centralized third-party provider using Wide
Area Networking (WAN) or Internet-based access technologies. ... In cloud networking,
the network can be shared as well as the computing resources.
Private cloud?
The cloud infrastructure is provisioned for exclusive use by a single organization comprising
multiple consumers (e.g., business units).
It may be owned, managed, and operated by the organization, a third party, or some
combination of them, and it may exist on or off premises.
The private cloud can be physically located at your organisation’s on-site datacenter but in a
private cloud, the services and infrastructure are always maintained on a private network and the
hardware and software are dedicatedsolely to your organisation.
More flexibility , High scalability , Improved security
Community cloud:

5. The cloud infrastructure is provisioned for exclusive use by a specific community of consumers
from organizations that have shared concerns (e.g., mission, security requirements, policy, and
compliance considerations).
It may be owned, managed, and operated by one or more of the organizations in the
community, a third party, or some combination of them, and it may exist on or off premises.
Public cloud:
The cloud infrastructure is provisioned for open use by the general public.
It may be owned, managed, and operated by a business, academic, or government organization,
or some combination of them.
It exists on the premises of the cloud provider
In a public cloud, you share the same hardware, storage and network devices with other
organisations or cloud “tenants.” You access services and manage your account using a web
browser.
Lower costs , No maintenance , Near-unlimited scalability , High reliability
Hybrid cloud:
The cloud infrastructure is a composition of two or more distinct cloud infrastructures (private,
community, or public).
Cloud computing
In the simplest terms, cloud computing means storing and accessing data and programs over
the Internet instead of your computer's hard drive. The cloud is just a metaphor for the
Internet. ... When you store data on or run programs from the hard drive, that's called local
storage and computing
Cloud computing is the the use of various services, such as software development platforms,
servers, storage and software, over the internet, often referred to as the "cloud."
CLOUD SERVICE MODELS
Software as a Service (SaaS):
The capability provided to the consumer is to use the provider’s applications running on a cloud
infrastructure. A cloud infrastructure is the collection of hardware and software that enables the
five essential characteristics of cloud computing.
The first cloud computing type is infrastructure-as-a-service (IaaS), which is used for
Internet-based access to storage and computing power. The most basic category of
cloud computing types, IaaS lets you rent IT infrastructure - servers and virtual
machines, storage, networks and operating systems - from a cloud provider on a pay-
as-you-go basis.

6. Platform as a Service (PaaS):
The capability provided to the consumer is to deploy onto the cloud infrastructure
consumer-created or acquired applications created using programming languages,
libraries, services, and tools supported by the provider.
The second cloud computing type is platform-as-a-service (PaaS) which gives
developers the tools to build and host web applications. PaaS is designed to give users
access to the components they require to quickly develop and operate web or mobile
applications over the Internet, without worrying about setting up or managing the
underlying infrastructure of servers, storage, networks and databases.
Infrastructure as a Service (IaaS):
The capability provided to the consumer is to provision processing, storage, networks,
and other fundamental computing resources where the consumer is able to deploy and
run arbitrary software, which can include operating systems and applications.
The consumer does not manage or control the underlying cloud infrastructure but has
control over operating systems, storage, and deployed applications; and possibly limited
control of selected networking components (e.g., host firewalls).
The third cloud computing type is software-as-a-service (SaaS) which is used for web-
based applications. SaaS is a method for delivering software applications over the
Internet where cloud providers host and manage the software applications making it
easier to have the same application on all of your devices at once by accessing it in the
cloud.
The special publication includes the five essential characteristics of cloud
computing:
1. On-demand self-service:A consumer can unilaterally provision computing capabilities,
such as server time and network storage, as needed automatically without requiring
human interaction with each service provider.
2. Broad network access: Capabilities are available over the network and accessed
through standard mechanisms that promote use by heterogeneous thin or thick client
platforms (e.g., mobile phones, tablets, laptops and workstations).
3. Resource pooling: The provider's computing resources are pooled to serve
multiple consumers using a multi-tenant model, with different physical and virtual
resources dynamically assigned and reassigned according to consumer demand. There

7. is a sense of location independence in that the customer generally has no control or
knowledge over the exact location of the provided resources but may be able to specify
location at a higher level of abstraction (e.g., country, state or datacenter). Examples of
resources include storage, processing, memory and network bandwidth.
4. Rapid elasticity: Capabilities can be elastically provisioned and released, in some
cases automatically, to scale rapidly outward and inward commensurate with demand.
To the consumer, the capabilities available for provisioning often appear to be unlimited
and can be appropriated in any quantity at any time.
5. Measured service:Cloud systems automatically control and optimize resource use
by leveraging a metering capability at some level of abstraction appropriate to the type of
service (e.g., storage, processing, bandwidth and active user accounts). Resource
usage can be monitored, controlled and reported, providing transparency for the provider
and consumer.
What are Cloud Service Providers?
Cloud service providers (CSP) are companies that offer network services, infrastructure,
or business applications in the cloud. The cloud services are hosted in a data center
that can be accessed by companies or individuals using network connectivity.
The large benefit of using a cloud service provider comes in efficiency and economies
of scale. Rather than individuals and companies building their own infrastructure to
support internal services and applications, the services can be purchased from the
CSP, which provide the services to many customers from a shared infrastructure.
There are several different forms of services that can be used “in the cloud” by CSPs,
including software, often referred to as Software as a Service (SaaS), a computing
platform for developing or hosting applications, known as Platform as a Service (PaaS);
or an entire networking or computing infrastructure, known as Infrastructure as a
Service (IaaS). The divisions, however, are not always clear-cut, as many providers
may offer multiple flavors of cloud services, include traditional web or application
hosting providers. For example, you might go to a cloud provider, such as Rackspace,
who started as a web hosting company and buy either PAAS or IAAS services. Many
cloud providers are focusing on specific verticals, such as hosting healthcare
applications in a secure IAAS environment.
Customer Focus: Cost, Reliability and Security
Advantages and disadvantages of Software as a Service (SaaS)
Software as a Service, also known as SaaS or on-demand software, is a way of delivering software
applications to the end-user over the internet. SaaS can provide great advantages for most businesses, primarily
in costs and flexibility. However, disadvantages of SaaS (such as lack of control) are considerable and should
not be ignored.
Benefits of SaaS

8. 
1. Cost – reduced for customer due to savings on human capital, physical
space, electricity, and support when SaaS is provided through a multi-tenant
distribution model.
2. Maintenance – easier because applications do not need to be installed on
each user’s computer and the vendor can deploy patches and updates
throughout the environment at a faster rate.
3. Access –faster because there is no installation or implementation process so
getting up and running can be quick. The software is essentially already
installed and running.
4. Device and location independence – improved because users can access
systems using a web browser regardless of their location or device.
5. Data analytics – less hassle because SaaS permits collection of anonymzed
metadata and metering, which can improve service and provide important
insights about the customer base.
6. Continuity – with the enhancement of cloud technology, redundancy
provides businesses with a continuity that is not easily accomplished.
7. Scalability SaaS providers generally offer many subscription options and flexibility
to change subscriptions as and when needed, eg when your business grows, or
more users need to access the service
8. Increase stability, reliability and supportability. With IaaS there is no need to
maintain and upgrade software and hardware or troubleshoot equipment
problems. With the appropriate agreement in place, the service provider assures
that your infrastructure is reliable and meets SLAs.
9. Better security. With the appropriate service agreement, a cloud service provider
can provide security for your applications and data that may be better than what
you can attain in-house.
Disadvantages of SaaS
 Loss of control. In-house software applications give business owners a high
degree of control. When you use a hosted solution, you turn much of that control
over to a third party provider. If you aren't comfortable relying on someone else to
manage critical business applications, an ASP platform may not be right for you.
 Limited applications. SaaS is gaining in popularity. However, there are still
many software applications that don't offer a hosted platform. You may find it
necessary to still host certain applications on site, especially if your company
relies on multiple software solutions.

9.  Connectivity requirements. Since SaaS software is web-hosted, you can't use
these applications without an Internet connection. If your Internet service goes
down or if mobile workers are in an Internet dead zone, you won't have access to
your software or data.
 Variable functions & features. In many cases, hosted applications are limited in
function. It's not uncommon for a hosted solution to lack some functions or
features that are standard in its client/server counterpart. You will need to
evaluate each application on a case-by-case basis to make sure your SaaS
solution offers the features you need to do business.
 Slower speeds. In general, SaaS applications run at slightly slower speeds than
client/server applications. Although their speed is still pretty good, you'll need to
be prepared for the possibility of a less-than-instant computing environment.
Working of end user
In information technology, the term end user is used to distinguish the person
for whom a hardware or software product is designed from the developers,
installers, and servicers of the product. The "end" part of the term probably
derives from the fact that most information technologies involve a chain of
interconnected product components at the end of which is the "user."
Frequently, complex products require the involvement of other-than-end users
such as installers, administrators, and system operators. The term end
user thus distinguishes the user for which the product is designed from other
users who are making the product possible for the end user. Often, the
term user would suffice.
Types of EUC
End-user computing encompasses a wide variety of user-facing resources, including:
 desktop and notebook computers;
 desktop operating systems and applications;
 smartphones, tablets, wearables and other mobile devices;
 mobile, web and cloud applications; and

10.  virtual desktops and applications.
What is Hypervisor and what types of hypervisors
A hypervisor is a process that separates a computer’s operating system and
applications from the underlying physical hardware. Usually done as software although
embedded hypervisors can be created for things like mobile devices.
The hypervisor drives the concept of virtualization by allowing the physical host machine
to operate multiple virtual machines as guests to help maximize the effective use of
computing resources such as memory, network bandwidth and CPU cycles.
Type 1 hypervisor: hypervisors run directly on the system hardware – A “bare metal” embedded
hypervisor,
Type 1 hypervisors, sometimes called “native” or “bare metal” hypervisors, run directly on the
host’s hardware to control the hardware and manage the guest VMs. Modern hypervisors
include Xen, Oracle VM Server for SPARC, Oracle VM Server for x86, Microsoft Hyper-V and
VMware’s ESX/ESXi.
2. Microsoft Hyper-V
The Microsoft hypervisor, Hyper-V doesn’t offer many of the advanced features that VMware’s
products provide.
However, with XenServer and vSphere, Hyper-V is one of the top 3 Type-1 hypervisors.
3. Citrix XenServer
It began as an open source project.
The core hypervisor technology is free, but like VMware’s free ESXi, it has almost no advanced
features.
4. Oracle VM
The Oracle hypervisor is based on the open source Xen.
However, if you need hypervisor support and product updates, it will cost you.
Oracle VM lacks many of the advanced features found in other bare-metal virtualization
hypervisors.
Type 2 hypervisor:
hypervisors run on a host operating system that provides virtualization services, such as I/O
device support and memory management.
1. VMware Workstation/Fusion/Player
VMware Player is a free virtualization hypervisor.

11. VMware Workstation has three major use cases:
 for running multiple different operating systems or versions of one OS on one desktop,
 for developers that need sandbox environments and snapshots, or
 for labs and demonstration purposes.
2. VMware Server
VMware Server is a free, hosted virtualization hypervisor that’s very similar to the VMware
Workstation.
VMware has halted development on Server since 2009
3. Microsoft Virtual PC
This is the latest Microsoft’s version of this hypervisor technology, Windows Virtual PC and runs
only on Windows 7 and supports only Windows operating systems running on it.
4. Oracle VM VirtualBox
VirtualBox hypervisor technology provides reasonable performance and features if you want to
virtualize on a budget. Despite being a free, hosted product with a very small footprint,
VirtualBox shares many features with VMware vSphere and Microsoft Hyper-V.
5. Red Hat Enterprise Virtualization
Red Hat’s Kernel-based Virtual Machine (KVM) has qualities of both a hosted and a bare-metal
virtualization hypervisor. It can turn the Linux kernel itself into a hypervisor so the VMs have
direct access to the physical hardware.
KVM :This is a virtualization infrastructure for the Linux kernel. It supports native virtualization
on processors with hardware virtualization extensions.
why should one prefer public cloud over private cloud
Cloud Computing is an integral part of businesses today. Private Cloud and Public
Cloud are two popular categories of this transformative network-computing model. For a
growing organization, it becomes imperative to learn the difference between the public
cloud and private cloud.
However, there is no doubt in the fact that this comparison is essential for all IT and
business heads and because of the increasing cloud dependency.
Features &
Benefits
Private Cloud Public Cloud

12. Access and
Storage
1. Restricted access to one
organization at a time
2. Offers a dedicated storage
infrastructure, which is not
accessible to others.
1. Access is available to multiple
organizations at once.
2. Data gets stored on a shared
infrastructure.
Location Of The
Data Center
Allows the organization to decide
and choose – an on-premise data
center or dedicated location on the
service provider’s infrastructure.
Location of the data center varies by
the public cloud provider’s
infrastructure site.
Investment
Requires additional investment in
the company’s hardware
components, like physical servers to
leverage private cloud services
efficiently.
Eliminates the need to invest in any
additional hardware or software
components.
Upgrades And
Management
A dedicated administrator is
required to manage the upgrades
and installations. Further, this
makes it easy to integrate their on-
premise or on-cloud applications.
The service provider performs the
management and rolls out of
updates without the company’s
intervention.
Security
Superior security mechanism. It is
with the option to implement higher
levels of authentication and security
for the cloud environment.
Offers a standard security protocol
that remains unaltered, and cannot
be enhanced or customized for
different business models.
Customization
Allow companies to customize their
cloud infrastructure according to
their business-specific needs and
Offers a standard operating
procedure for organizations
Costs
1. Expensive as it involves
additional cost investment to set up
on-premise data centers or hire
dedicated administrators.
2. It is also a pre-requisite while
opting for services
Less expensive as there are no
additional costs
Scalability
1. Offers incremental space and
infrastructural abilities.
2. Though, Private Cloud is more
responsive and offers customized
scalability
Offers additional space and
infrastructure abilities

13. Main feature of cloud computing services
1. Infrastructure
2. Software
3. Platform
4. Services
Community cloud
1. For a group and community
2. For multiple sites of organization
3. Where user want secure connectivity
Hybrid Cloud
1 Combination of two cloud
2 Depends of customer needs and demand