IT Infrastructure

The term IT infrastructure is defined as a combined set of hardware, software, networks, facilities, etc. (including all of the information technology related equipment), used to develop, test, deliver, monitor, control or support IT services. Associated people, processes and documentation are not part of IT Infrastructure.

Information technology infrastructure is defined broadly as a set of information technology (IT) components that are the foundation of an IT service: typically physical components (computer and networking hardware and facilities), but also various software and network components.

The fields of IT management and IT service management rely on IT infrastructure, and the ITIL framework was developed as a set of best practices with regard to IT infrastructure.

Switching

A network switch is the device that provides connectivity between network devices on a Local Area Network (LAN). A switch contains several ports that physically connect to other network devices – including other switches, routers and servers. Early networks used bridges, in which each device “saw” the traffic of all other devices on the network. Switches allow two devices on the network to talk to each other without having to forward that traffic to all devices on the network.

Routers

Routers move packets between networks. Routing allows devices separated on different LAN’s to talk to each other by determining the next “hop” that will allow the network packet to eventually get to its destination.

If you have ever manually configured your IP address on a workstation, the default gateway value that you keyed in was the IP address of your router.

Firewalls

Firewalls are security devices at the edge of the network. The firewall can be thought of as the guardian or gatekeeper.

A set of rules defines what types of network traffic will be allowed through the firewall and what will be blocked.

In the simplest version of a firewall, rules can be created which allow a specific port and /or protocol for traffic from one device (or a group of devices) to a device or group of devices. For example: if you want to host your own web server and only limit it to only web traffic, you would typically have two firewall rules that look something like this:

Servers

A network server is simply just another computer but usually larger in terms of resources than what most people think of. A server allows multiple users to access and share its resources. There are several types of servers.

• Perhaps the most common type of server is a file server. A file server provides end users with a centralized location to store files. When configured correctly, file servers can allow or prevent specific users to access files.
• Another common type of server is a directory server. A directory server provides a central database of user accounts that can be used by several computers. This allows centralized management of user accounts which are used to access server resources.
• Perhaps the most common type of server is a web server. Web servers use HTTP (Hyper Text Transfer Protocol) to provide files to users through a web browser.
• There are also application servers, database servers, print servers, etc.

Physical plant

The physical plant is the entire network cabling in your office buildings and server room/ datacenter. This all too often neglected part of your infrastructure usually is the weakest link and is the cause of most system outages when not managed properly. There are two main types of cabling in the infrastructure -CAT 5/6/7 and fiber optic. Each type of cabling has several different subtypes depending on the speed and distance required to connect devices.

People

By the strict definition, people are not considered part of the network infrastructure. However, without competent well-qualified people in charge of running and maintaining your infrastructure, you will artificially limit the capabilities of your organization. In larger organizations, there are specialty positions for each of the areas mentioned in this article. In smaller organizations, you will find that the general systems administrator handles many of the roles.

Server rooms / Data center

The server room, or data center (in large organizations), can be thought of as the central core of your network. It is the location in which you place all of your servers and usually acts as the center of most networks.

Infrastructure Software

This is perhaps the most “gray” of all infrastructure components. However, server operating systems and directory services(like MS Active Directory) are considered to be part of the infrastructure. Without multi-user operating systems, the hardware can’t perform its infrastructure functions.