e following. Layer 2: Switches This layer corresponds to capabilities in the Data Link Layer, functioning as the links to the network. However, Layer 2 devices cannot choose between multiple routes in a network. Layer 2 switches are placed in wiring closets in LANs and route messages to devices within their LAN segment. See Figure 1-6 for an illustration of how this works. Layer 3: Switches and Routers Layer 3 corresponds to the Network Layer. These devices can select an optimal route for each packet. Rout- ers select paths for packets on the Internet and route messages between networks. Layer 5: Encryption Protocols These are session layer protocols that reorder data in packets by using complex mathematical algorithms to keep data private. Cloud Computing AT&T network Layer 2 switch transmits message to devices within LAN segments Verizon network Layer 3 router transmits message to devices within LAN segments Sprint network Carriers' routers transmit messages to other networks, locations on their own network, or Internet sites, based on IP address Figure 1-6 A router at a carrier's site sends traffic to other carriers, based on factors such as destination address and cost of transmitting via particular carriers. Layer 7: Deep Packet Inspection (DPI) DPI services include application layer capability. It can look into packets to determine the application of the data within them. Knowing the capabilities in each layer helps in understanding the protocol and equipment capabilities being described. CLOUD COMPUTING Cloud computing refers to the paradigm by which computing functions, document storage, software applications, and parts of or all of a data center are located and main- tained at an external provider's site. There are many reason why an organization would want to adopt a cloud-computing strategy. Most of these reasons revolve around the desire to carry out IT functions more cost-effectively. Another reason might be capital outlays. A small startup company, for example, might not have the resources to hire s