Access and Switching techniques for the broadband network

The objectives and the early technical results of a project for the realization of an ATM local network testbed are described. The aim of the project is to realize a flexible experimentation environment to investigate the critical issues related to the introduction of ATM techniques in the network, including signalling, interworking and service support, in addition to the basic switching technology. After presenting the general structure and the solutions adopted for the testbed, the paper describes the main characteristics of its building blocks currently under development: the switching node with its ATM switching fabric and control units, the access network with the related interfaces and protocols, the customer equipment composed by ATM workstations, ATM terminal adaptors and LAN gateways, the interworking unit connecting the testbed to the telephone network. Finally the resources allocation and policing functions adopted are also discussed