 to compile a list of all the devices that will be accessing the network. In the case of LANs, here are some things to think about: How many users will the network need to support? How many servers will the network need to support? How many printers will be attached to the network, and what will their locations What are the applications running on the network? How will users interact with these applications (HTTP, client software, terminals, Citrix)? What type of security do you need? Is high availability desired and/or affordable? What percentage of growth should you assume? Documentation Do all interfaces need to be gigabit? Do you need 10-gigabit? Will the network need to support VoIP? Will you be supporting one physical location or many (including multiple floors in a single building)? Your goal is to come up with a target number of each interface type for each location. Once you have these numbers in mind, you can decide what sort of equipment you need to order. Gigabit Ethernet switches come in multiples of 48 at the highest port densities currently available. To determine how many 48-port switches or modules you need, divide the total number of gigabit interfaces required by 48. For example, if you need 340 gigabit interfaces in one location, you'll need 340 / 48 = 7.08 (in other words, eight modules). When figuring out how many ports you need, don't forget servers that offer high availability. Many servers today will allow multiple Ethernet interfaces to be connected to one of two switches in a failover pair. Talk with your systems people and find out what they're doing SO you don't come up short. You should also plan for a certain amount of growth. A good rule of thumb for capacity planning is to plan for a minimum of 15 percent growth: 340 * 1.15 = 391. Divide this number by 48 to see how many modules you'll need if you want to allow for growth: 391 / 48 = 8.15. This means you'll need nine modules, which will provide a total of 432 ports. Nine is an odd number, which means one switch will have more modu