1. IT Infrastructure Chap 1: Definition
Mark Abraham Magumba

2. The Evolution of IT Infrastructure
During the first years IT infrastructures were relatively simple
With the advent of more advanced applications like ERP, E-commerce and data ware housing they’ve become more complex
Many IT infrastructures are the result of an incremental process of implementation, acquisition and mergers
The result it is that most are extremely complex and ineficient with little integration and interoperability

3. IT infrastructure Definitions
The equipment, systems, software, services used in common across organizations regardless of mission, program or project. Also serves as the foundation upon which mission, program and project specific services are built
All of the configuration components that are necessary to provide services to the customers
All of the hardware, software, networks, facilities e.tc. That are required to deliver, monitor, control or support IT services. The term It infrastructure includes all IT but not associated people, processes and documentation
The distributed operational and administrative computing environment hidden from the unseen world of application users

4. Infrastructure definition contd
Different Views of infrastructure
Business processes
Information
Infrastructure for business analyst
Application
Infrastructure for end user
Server
Infrastructure for end user
Building
Electricity

5. Typical Characteristics of infrastructure
Infrastructure provides services to applications
Infrastructure is usually shared by multiple applications
It infrastructure is more static and permanent than the applications running on it
The management of infrastructure is separate from the management of the application running on it
The department owning the infrastructure is separate from the department owning the applications

6. The infrastructure Model

7. The infrastructure model
The model depicts the infrastructure itself and the “users” of the infrastructure
The users are the applications that deliver utility to the system users built on top of the infrastructure and these are
Middleware and databases
Applications
Processes and information

8. Virtualization: Acts as abstraction layer between the hardware and the operating system, it allows a single physical device to run multiple operating systems
Operating system: A collection of programs to manage a computers inner workings including its memory, storage, hardware and file system
End user devices: The devices used by end users to use to run applications such as PCs, thin clients, smart phones

9. IT infrastructure building blocks
The model also describes the IT infrastructure building blocks
Data centers: Typically IT hardware is provided in data centers. These provide (uninterrupted) power supply, cooling, computer racks, availability and security measures
Servers: Are physical and main processing units also known as computers found in the data centers
Networks: Connect the different components of the data center. Comprise routers, switches, cabling and include LANs, WANs, VPNS and simple services such as DHCP and DNS
Storage: Servers can have internal storage like hard disks and external storage like tapes, Direct Attached Storage (DAS), Network Attached Storage (NAS), Storage Area Networks (SAN)

10. Non Functional Attributes
Vertically three essential non functional attributes including availability, security and performance are shown
Availability: is about maximizing system uptime and includes elements like backup, restore and disaster recovery, failover, clustering and replication
Performance which includes areas such as scaling, load balancing, virtualization, Quality of Service (QoS) and high performance clustering
Security which is about minimizing threats and vulnerabilities and includes solutions such as Virtual Private Networks (VPN), Intrusion Detection Systems (IDS), access control and encryption
The three non functional attributes can all be affected by the configuration of each of the infrastructure components
Though several other non functional attributes can be defined these three are the most critical