As broadband multimedia applications to the desk top are becoming popular today, the high-speed bandwidth demand from a single user will occupy large shares of the LAN's channel capacity. Therefore, the evolution of LAN technologies has shifted from shared to dedicated media. More and more LANs are being installed and their interconnection will require parallel switching techniques such as a high-speed switching hub. The ATM small cell-size switching approach is intended to accommodate the mixed media such as voice, data and video. To fulfil the switching cost, bandwidth and latency criteria, a two-stage switching hub for LAN interconnection is designed and presented in this paper. The packet switching technique is used in the first stage switching to efficiently interconnect the local LANs. For the second stage design, the ATM cell switching is adopted to accommodate multimedia traffic and internetworking among LANs and WANs. The switching architecture including both the packet and cell switching units is thoroughly described. The message flow and routing mechanism are presented in the paper. This architecture has been proved to have the advantages of very low latency, flexible scalability and easy routing management with two-way learning.>

A single international-standard ISDN (integrated services digital network) basic rate interface (BRI) has been arranged so that a data terminal and either two, three, or four voice terminals can be operated simultaneously through the interface. The switch access architecture for quad voice lines with data-on-demand ISDN BRI (basic rate interface) is introduced. The BRI S/T interface bit framing requirements and the Q.931 call control procedures required for the new service are discussed. The results show that relatively simple additional hardware could be used to upgrade an existing ISDN 5ESS switch to quad voice lines with data capability per BRI.>