Network Topologies
There exist a number of network topologies that depend on the size and type of each organization. Some organizations will have a presence of each of the following topologies while others may only utilize a subset of this list. Refer to the list that follows and Figure 1-1 through Figure 1-4 for a description and depiction of each of the different topologies that can make up an entire organization’s network.
Campus-Area Network (CAN): A campus-area network, as illustrated in Figure 1-1, is the network topology used to provide connectivity, data, applications, and services to users of an organization that are physically located at the corporate office (headquarters). The CAN includes a module for each building in the campus, for the data center, for WAN Aggregation, and for the Internet Edge. Security with the Campus Area Network.
Cloud, Wide-Area Network (WAN): The cloud and WAN provide a logical and physical location for data and applications that an organization prefers to have moved off-site, as illustrated in Figure 1-2. This alleviates an organization from having to expend resources to operate, maintain, and manage the services that have been previously located within the organization’s purview.
Data Center: The Data Center network contains the Unified Computing System (UCS) servers, voice gateways, and CUCM servers supporting the VoIP environment, all of which is provided network connectivity by a series of Nexus switches, as illustrated in Figure 1-3. The entire Data Center network is protected by a set of firewalls at the edge that filters all traffic ingressing and egressing the Data Center.
Small office/Home office (SOHO): The remote SOHO site will provide connectivity to the SOHO users through the use of WAN routers that find their way back to the WAN Aggregation module in the CAN via MPLS WANs, as illustrated in Figure 1-4. Within the SOHO, users are provided network connectivity through the presence of access switches.
