Enterprise Network and the Hierarchical Network Model
What do you mean by an enterprise network?
The network that provides connectivity among users and devices in a mid-size to large organisation is known as an enterprise network. In much simpler words, an enterprise network is the network that is needed to support a large business.
Why do you need an enterprise network?
In order to be successful, businesses need to continuously grow and evolve. For example, if I start a company today, it will probably be on a very small scale, in a single location, maybe just from my own cosy room. I am hardworking and ambitious and so I want to make my company a global enterprise. I start working on my company and am able to afford a few employees to work for me. I might even move to a small office space at this point. Slowly and steadily, the profits are good and in a few more years I was able to move into a bigger office and expand my business into a few more places in the city and then to a couple of different countries if the conditions work for me. Looking back, the company that was started in a single room has now become international. This means that the network required to support my company on the first day obviously cannot support it today. Networks need to be rapidly updated to support the growing business. When a small business grows into a large business environment with many users and multiple locations it is called an enterprise and the network that supports such a business is called an enterprise network.
More on enterprise networks
An enterprise network should support the exchange of all types of network traffic including data files, emails, IP telephony, and video applications for multiple business units. They should support all the business needs of the enterprise, support converged network traffic and provide centralised administrative control.
A term I had to google:
IP telephony (Internet Protocol telephony) is a general term for technologies, products and services that use the Internet Protocol’s packet-switched connections to support voice calling, voicemail, video calling, video conferencing, faxing and instant messaging (IM).
Enterprise devices
Enterprise devices are expected to be up and running for most of the time. In case of outages, the normal activities of the business are hampered, causing losses in revenue, opportunities and customers. This means that reliability is one of the most important qualities to look out for when choosing a device to implement an enterprise network. Therefore, all the equipment used in this type of network is high-end, designed and manufactured to more stringent standards than other conventional network devices (in this context non-enterprise network devices). Since enterprise networks are designed for large business it has the capability of moving a large amount of data, it has to be reliable with features like redundant power capacity and failover capabilities. Failover capacity refers to the ability of a device to switch from a nonfunctioning module, service, or device to a functioning one with little or no break in service. Something to be mindful of is that using high-end devices does not eliminate the need for network design.
Hierarchical network design
To optimise the bandwidth on a network, the network traffic must stay local and not propagate unnecessarily onto other parts of the network.
The network functionality is divided into 3 layers: Access, Distribution and Core layers.
If you have already studied the model and are looking for a quick recap, the model can be summarised as follows:
Access layer: Provides connectivity for users to the network. User traffic is initiated at the access layer and passes through the other layers if required.
Distribution layer: forwards traffic from one local network to another.
Core layer: high-speed backbone layer between dispersed networks.
Note: Some smaller enterprise networks might implement a two-tier hierarchical design where the core and distribution layers are collapsed into one layer, reducing cost and complexity.
For the readers studying this model for the first time, here is an elaborate explanation starting from the bottom-most layer:
- The access layer allows the users of the network to connect to the wired ethernet network thus allowing the users to share information with the local network. This layer incorporates switches and hubs. (check out https://medium.com/@madhumitamenon/hubs-switches-routers-what-are-they-d34abc343a9b)
- Since enterprise networks support large businesses it is safe to say that there will be multiple local networks in the enterprise network. The distribution layer connects these local networks together. It also ensures that the local traffic remains confined to local networks.
- The core layer connects multiple distribution layer devices together and manages the traffic within the network.