Article · Wikipedia archive · Last revised Jun 19, 2026

Switched Multi-megabit Data Service

Switched Multi-megabit Data Service (SMDS) was a connectionless service used to connect LANs, MANs and WANs to exchange data, in early 1990s. In Europe, the service was known as Connectionless Broadband Data Service (CBDS).

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Switched Multi-megabit Data Service (SMDS) was a connectionless service used to connect LANs, MANs and WANs to exchange data, in early 1990s. In Europe, the service was known as Connectionless Broadband Data Service (CBDS).1: 510 

SMDS was specified by Bellcore,234 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 SONET5 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 matured.1: 510  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.1: 214  In the mid-1990s, SMDS was replaced, largely by Frame Relay.

References

References

  1. McDysan, David E.; Darren L. Spohn (1999). ATM Theory and Applications. Montreal: McGraw-Hill. ISBN 0-07-045346-2.
  2. TR-TSV-000772 Generic System Requirements in Support of Switched Multi-Megabit Data Service, Telcordia.
  3. TR-TSV-000773 Local Access System Generic Requirements, Objectives, and Interfaces in Support of Switched Multi-Megabit Data Service, Telcordia.
  4. TR-TSV-000774 Switched Multi-Megabit Data Service (SMDS) Operations Technology Network Element Generic Requirements, Telcordia.
  5. GR-253 SONET Transport Systems: Common Generic Criteria, Telcordia.
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