A symmetric digital subscriber line (SDSL) is a digital subscriber line (DSL) that transmits digital data over the copper wires of the telephone network, where the bandwidth in the downstream direction, from the network to the subscriber, is identical to the bandwidth in the upstream direction, from the subscriber to the network. This symmetric bandwidth can be considered to be the opposite of the asymmetric bandwidth offered by asymmetric digital subscriber line (ADSL) technologies, where the upstream bandwidth is lower than the downstream bandwidth. SDSL is generally marketed at business customers, while ADSL is marketed at private as well as business customers.
More specifically, SDSL can be understood as:
In the wider sense, an umbrella term for all DSL variant which offer symmetric bandwidth, including IDSL, which offers 144 kbit/s, HDSL, HDSL2, G.SHDSL, which offers up to 22.784 Mbit/s over four pairs of copper wires, as well as the SDSL variant below
In the narrow sense, a particular proprietary and non-standardized DSL variant for operation at 1.544 Mbit/s or 2.048 Mbit/s over a single pair of copper wires, without support for analog calls on the same line
SDSL is a rate-adaptive digital subscriber line (DSL) variant with T1/E1-like data rates (T1: 1.544 Mbit/s, E1: 2.048 Mbit/s). It runs over one pair of copper wires, with a maximum range of 10,000 feet (3,000 m). It cannot co-exist with a conventional voice service on the same pair as it takes over the entire bandwidth.[1]
Standardization effortsEdit
SDSL is a proprietary technology that was never standardized. As such it usually only interoperates with devices from the same vendor. It is the predecessor of G.SHDSL which was standardized in February 2001 by ITU-T with recommendation G.991.2.[2] SDSL is often confused with G.SHDSL and HDSL;[3] in Europe, G.SHDSL was standardized by ETSI using the name 'SDSL'. This ETSI variant is compatible with the ITU-T G.SHDSL standardized regional variant for Europe.
As there is a standardised successor available, SDSL installations today are considered legacy. Most new installations use G.SHDSL equipment instead of SDSL.[citation needed]
Target audienceEdit
SDSL typically falls between ADSL and T1/E1 in price and was mainly targeted at small and medium businesses which don't need the service guarantees of Frame Relay or the higher performance of a leased line.[4]
^"Internetworking Technology Handbook". Cisco Systems, Inc. Retrieved 2008-12-03.
October 21, 2023
symmetric, digital, subscriber, line, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, schol. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Symmetric digital subscriber line news newspapers books scholar JSTOR December 2008 Learn how and when to remove this template message A symmetric digital subscriber line SDSL is a digital subscriber line DSL that transmits digital data over the copper wires of the telephone network where the bandwidth in the downstream direction from the network to the subscriber is identical to the bandwidth in the upstream direction from the subscriber to the network This symmetric bandwidth can be considered to be the opposite of the asymmetric bandwidth offered by asymmetric digital subscriber line ADSL technologies where the upstream bandwidth is lower than the downstream bandwidth SDSL is generally marketed at business customers while ADSL is marketed at private as well as business customers More specifically SDSL can be understood as In the wider sense an umbrella term for all DSL variant which offer symmetric bandwidth including IDSL which offers 144 kbit s HDSL HDSL2 G SHDSL which offers up to 22 784 Mbit s over four pairs of copper wires as well as the SDSL variant below In the narrow sense a particular proprietary and non standardized DSL variant for operation at 1 544 Mbit s or 2 048 Mbit s over a single pair of copper wires without support for analog calls on the same line A term used by ETSI to refer to G SHDSLContents 1 Proprietary SDSL technology 1 1 Standardization efforts 1 2 Target audience 2 See also 3 ReferencesProprietary SDSL technology EditSDSL is a rate adaptive digital subscriber line DSL variant with T1 E1 like data rates T1 1 544 Mbit s E1 2 048 Mbit s It runs over one pair of copper wires with a maximum range of 10 000 feet 3 000 m It cannot co exist with a conventional voice service on the same pair as it takes over the entire bandwidth 1 Standardization efforts Edit SDSL is a proprietary technology that was never standardized As such it usually only interoperates with devices from the same vendor It is the predecessor of G SHDSL which was standardized in February 2001 by ITU T with recommendation G 991 2 2 SDSL is often confused with G SHDSL and HDSL 3 in Europe G SHDSL was standardized by ETSI using the name SDSL This ETSI variant is compatible with the ITU T G SHDSL standardized regional variant for Europe As there is a standardised successor available SDSL installations today are considered legacy Most new installations use G SHDSL equipment instead of SDSL citation needed Target audience Edit SDSL typically falls between ADSL and T1 E1 in price and was mainly targeted at small and medium businesses which don t need the service guarantees of Frame Relay or the higher performance of a leased line 4 See also EditISDN List of interface bit ratesReferences Edit Internetworking Technology Handbook Cisco Systems Inc Retrieved 2008 12 03 G 991 2 Single pair high speed digital subscriber line SHDSL transceivers ITU T Retrieved 2008 12 04 Technology Overviews DSL Black Box Network Services Retrieved 2008 12 04 Internetworking Technology Handbook Cisco Systems Inc Retrieved 2008 12 03 Retrieved from https en wikipedia org w index php title Symmetric digital subscriber line amp oldid 1166450845, wikipedia, wiki, book, books, library,
