What Does Switched Multimegabit Data Service Mean?
A switched multimegabit data service (SMDS) is a connectionless telecommunications service allowing organizations to exchange large amounts of data over a wide area network (WAN) on a non-constant or burst basis. SMDS is usually provided by telephone companies as a value-added service.
SMDS extends the abilities of an organization’s local area network (LAN) over a wide area on an as-needed basis. If a regional office of a commercial bank only needs to send data once a day to the central headquarters, there is no need to have a dedicated wide area network (WAN) connection, which will be idle most of the day. SMDS offers a solution through use of public telecommunications facilities to periodically send a burst of data, but only when and as needed.
Techopedia Explains Switched Multimegabit Data Service
SMDS is not a protocol but rather a telecommunications service. It can be used by any protocol supporting connectionless communications. A connectionless communication is one in which the sender does not check the existence of the receiver before sending. It is analogous to sending letters through the post office without verifying the correct receiving address.
Though SMDS is a reliable and high-speed solution, it is quite expensive. It has been largely replaced by newer technologies such as multiprotocol label switching (MPLS) and IP-based telecommunications.