Switched Multi-megabit Data Service (SMDS) was a
connectionless service used to connect
LAN
Lan or LAN may also refer to:
Science and technology
* Local asymptotic normality, a fundamental property of regular models in statistics
* Longitude of the ascending node, one of the orbital elements used to specify the orbit of an object in sp ...
s,
MAN
A man is an adult male human. Prior to adulthood, a male human is referred to as a boy (a male child or adolescent). Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chrom ...
s and
WANs to exchange data, in early 1990s. In Europe, the service was known as Connectionless Broadband Data Service (CBDS).
SMDS was specified by Bellcore,
and was based on the
IEEE 802.6 metropolitan area network (MAN) standard, as implemented by Bellcore, and used
cell relay transport,
Distributed Queue Dual Bus layer-2 switching arbitrator, and standard
SONET or
G.703 as access interfaces.
It is a switching service that provides data transmission in the range between 1.544 Mbit/s (T1 or DS1) to 45 Mbit/s (T3 or DS3). SMDS was developed by Bellcore as an interim service until
Asynchronous Transfer Mode
Asynchronous Transfer Mode (ATM) is a telecommunications standard defined by American National Standards Institute (ANSI) and ITU-T (formerly CCITT) for digital transmission of multiple types of traffic. ATM was developed to meet the needs o ...
matured.
SMDS was notable for its initial introduction of the 53-byte cell and cell switching approaches, as well as the method of inserting 53-byte cells onto G.703 and SONET.
In the mid-1990s, SMDS was replaced, largely by
Frame Relay
Frame Relay is a standardized wide area network (WAN) technology that specifies the physical and data link layers of digital telecommunications channels using a packet switching methodology. Originally designed for transport across Integrated ...
.
References
External links
Cisco guide to SMDS
Computer networking
{{compu-network-stub