SMDS (Paperback)

High Quality Content by WIKIPEDIA articles! Switched multimegabit data service (SMDS) was a connectionless service used to connect LANs, MANs and WANs to exchange data. SMDS was based on the IEEE 802.6 DQDB (Distributed Queue Dual Bus) standard. SMDS fragmented its datagrams into smaller "cells" for transport, and can be viewed as a technological precursor of ATM. Increases in raw data rates removed the need for fragmentation into cells, and SMDS' niche market position ensured that it remained a high-priced service. As a result, SMDS has been supplanted by IP-based and Ethernet-based services and MPLS.