Understanding the AVVID Architecture

Today's networks transport an increasingly wide array of services such as voice and video, and application traffic including critical e-business and communication services. To assist network architects in the proper design of capable networks, Cisco created the Architecture for Voice, Video, and Integrated Data (AVVID). The AVVID architecture is based on an open, multiservice model and is composed of four interrelated, yet distinct layers as follows:

These components provide reliable and efficient communication between the Client Layer, composed of AVVID appliances such as IP phones, wireless devices, PCs, and video equipment and the Application Layer. The Client Layer has become increasingly sophisticated in recent years to fully leverage the growing list of advanced applications that promote enhanced business functionality. This sophistication places demands on the Network Infrastructure Layer for increased throughput, reduced latency, and more focused services. For example, the network capabilities delivered to the IP Telephone switch port might be different than those provided to a typical desktop workstation switch port. This could be provided by ingress port QoS classification and marking in the Network Infrastructure Layer and controlled via the Services Control Layer, which proves the need for holistic and comprehensive AVVID design.

The Application Layer provides the tools and logic that promote more efficient and capable business processing. The Application Layer includes functionality such as telephony application, messaging, video content distribution, and e-commerce services. Each of these services relies on the proper implementation of the Network Infrastructure Layer. An example of an Application Layer component is Cisco Call Manager. This application provides the functionality and logic behind the IP phones within the enterprise. It relies on other applications such as Directory Services to provide authentication and unique services to each IP Phone user. Along with the Client Layer IP Phones, it also relies on a well-built and functional network over which it can provide services.

The overarching theme of the AVVID architecture is the use of a single converged IP network for voice, video, and data traffic. Doing so facilitates gains in operational and technical efficiency, and reduces total cost of ownership for those migrating from traditional separation of services across multiple infrastructures. AVVID also incorporates centralized control and management of the infrastructure for increased administrative productivity.

The benefits of AVVID are