Enterprise networking is the equipment and software that an office, campus or data centre uses to run its own private network. When your laptop joins the office Wi-Fi, finds the printer, opens the company's internal tools and reaches the internet, all of this happens on equipment that your employer bought and runs. None of it belongs to an operator such as Jio or Airtel, whose telecom networks carry traffic between organisations.
Every bank, hospital, college, factory and hotel needs a network of this kind. So there are hundreds of thousands of buyers, from a one-room clinic to a large bank. The equipment makers cannot visit each one. They sell mostly through channel partners: resellers sell the equipment, and system integrators install it and set it up.
Here is a typical case. A new employee joins the Kolkata branch of an insurance company and opens her laptop on her first morning.
First, the laptop joins the Wi-Fi. A Wi-Fi access point on the ceiling is a small radio that connects laptops and phones to the wired network. The branch's access points are set up from a cloud dashboard, so the IT team at head office can manage them without visiting Kolkata. Before the laptop is let in, the network checks that it is a company laptop.
Second, the laptop gets an address. Every device on a network needs an IP address, a number such as 10.24.3.57 that other devices use to reach it. A DDI system lends the laptop its address. It also turns names such as printer-2f.company.in into addresses, using DNS, the system that converts names into numbers.
Third, she prints a form. The print job travels through the switches in the office cupboard. A switch is a box with many cable sockets. It joins the access points, the desk computers and the printer, and sends each piece of data to the right one.
Fourth, she opens the claims app. The app runs in the company's data centre in Mumbai, on many servers at once. A load balancer picks a server that is not busy and sends her request to it.
Fifth, she opens her email, which runs in the cloud. The branch connects to head office and to the internet over ordinary broadband and mobile data links, managed by SD-WAN software. The company's apps run in more than one public cloud, so multi-cloud networking joins them into one network.
Being inside the office network no longer means being trusted. Under zero trust, every request is checked, wherever it comes from. Most of these networks also have spare links and spare equipment, so that one failure does not stop work. This is called redundancy.