Dial access stack architecture

摘要

A Dial Access Stack Architecture (DASA) includes a stack of Network Access Servers (NASs) each independently establishing and processing information for communication links on a public telephone network. A primary interconnect couples the stack of network access servers together through a primary network. A routing engine is coupled through the primary interconnect to the stack of network access servers routing packets between the network access servers and an Internet network. A secondary interconnect couples the stack of network access servers together through a secondary network that operates independently of the primary interconnect. The primary or secondary interconnects each allow pairs of the network access servers to communicate with each other in parallel and independently of the routing engine. The DASA provides scalability and resiliency to fault conditions and can easily aggregate and integrate any new access media. Applications such as voice, video and multicasting can be seamlessly added. The DASA architecture can scale from hundreds to thousands of ports at optimal cost and performance while avoiding any single point of failure.