Scalability

Future-ready enterprise networks should be able to expand on-demand to enable rapid growth of IT services and applications. The traffic patterns and user behavior are changing very fast. Any new trigger can bring a drastic change in the existing traffic patterns and user behavior. To address these needs, the enterprise network must be able to scale efficiently to accommodate capacity needs.

Scalability is the ability of the network to handle more traffic and applies to all domains of the network from the LAN, WAN, IoT, data center, and so on. A scalable network means that you would be able to augment the capacity of the network as the load increases without having to make any changes to the fundamental design of the network.

Scalability could be horizontal or vertical. Vertical scaling means the ability to expand the capacity of the network by augmenting the capacity within the system. Horizontal scaling is the ability to augment the capacity by adding more of the already existing infrastructure and split the load between them, by making them logically look like one entity.

Note that what may be considered horizontal or vertical scalability depends on the user's perspective. For example, adding more servers behind a load balancer in a DC to augment capacity would be considered horizontal scaling with respect to compute scale. However, the same compute capacity addition within the DC would be considered vertical scaling from a DC scaling perspective, and adding another DC and load balancing between the two data centers would be considered horizontal scaling. In general, horizontal scaling takes more planning and effort than vertical scaling.