Businesses that operate large enterprise networks strive to create an enterprise-wide networked infrastructure and interactive services to serve as a solid foundation for business and collaborative applications. This section explores some of the interactive services with respect to the modules that form the Cisco Enterprise Architecture.

KEY POINT A network service is a supporting and necessary service, but not an ultimate solution. For example, security and QoS are not ultimate goals for a network; they are necessary to enable other services and applications and are therefore classified as network services. However, IP telephony might be an ultimate goal of a network and is therefore a network application (or solution), rather than a service.