THE NBBS ACCESS NODE

Networking Broadband Services (NBBS) is an advanced wide-area-networki ng architecture that provides a rich set of services to support emergi ng applications for which quality of service and bandwidth reservation are critical, as well as legacy applications. The advanced features p rovided by the NBBS architecture require that each network node mainta in a fully replicated topology database. As the size of the network in creases, the network control costs at each network node become prohibi tively high. The NBBS access node is a low-cost end node that introduc es a hierarchical structure to the NBBS architecture, holding down net work control costs while allowing the network to increase in sire. The access node contains a subset of NBBS services. It is restricted to t he periphery of the network and does not perform intermediate-node swi tching functions. It provides access to the NBBS backbone network by n egotiating a relationship with an immediately attached network node (s erver network node) to obtain full NBBS services. In this paper, we di scuss the requirements for the NBBS access node, examine the relations hip between the access node and the server network node, and provide a n overview of the access node architecture.