What are some of the things you consider when designing an enterprise network?

"Some of the things I consider when beginning to design a complex enterprise network are the number of nodes or users, the applications that the users will be running, the topology of the network, and how many buildings, floors, and offices will be included, and the need to provide network access outside of the main campus. I consider the security requirements, whether the organization needs an extranet, the performance expectations of each department, and finally, the budget. Once I understand all of these factors, I can begin designing the network which will result in maximum performance at the least possible cost."