When discussing network design, it is useful to categorize networks based on the number of devices serviced:
- Small network - Provides services for up to 200 devices.
- Medium-sized network - Provides services for 200 to 1000 devices.
- Large network - Provides services for 1000+ devices.
Network designs vary depending on the size and requirements of the organizations. For example, the networking infrastructure needs of a small organization with fewer devices will be less complex than the infrastructure of a large organization with a significant number of devices and connections.
There are many variables to consider when designing a network. For instance, consider the example in the figure. The sample high-level topology diagram is for a large enterprise network that consists of a main campus site connecting small, medium, and large sites.
Network design is an expanding area and requires a great deal of knowledge and experience. The intent of this section is to introduce commonly accepted network design concepts.
Note: The Cisco Certified Design Associate (CCDA®) is an industry-recognized certification for network design engineers, technicians, and support engineers, who demonstrate the skills required to design basic campus, data center, security, voice, and wireless networks.