"ISDN, HDSL, ADSL, VDSL and SDSL are all DSL modem technologies designed to operate on telephone wires intended originally for voice-band communication (300Hz to 3.4kHz)....". The ISDN signals reside above the voice band. Upload signaling in the band just above POTS followed by Download signaling above that. The phone is required to have a Low-Pass filter installed to block the DSL information. The rates vary depending on the type of DSL service, and all require a Central Office location near the service. Both sides of the service require a DSL modem.
DSL; Digital Subscriber Line. Or xDSL which refers to any of the
DSL types.
ADSL; Asymmetric Digital Subscriber Line [one speed for download
and another for upload. ADSL can run up to 18,000 feet [1.544 Mbps
(T1)]]
SDSL; Symmetric Digital Subscriber Line. [same speed for upload or
download. Uses one wire pair, with no analog phone on the line. SDSL is a
single pair version of HDSL. One pair of wires can run up to 9,000ft at
768kbps.]
HDSL; High Data Rate DSL [Same speed for up-load or download. May
be 1 or 2 wire pair, with no analog phone on the line. HDSL can run up to
12,000 ft [384 Kbps and 2 Mbps]]
VDSL; Very high-speed DSL [type of ADS, used with incoming fiber
to copper junction. VDSL can run at 12.96 Mbps (1/4 STS-1) 4,500
feet.]
RADSL; Rate Adaptive DSL [type of ADS, the rate changes depending
on line quality]
IDSL; ISDN DSL [Same speed for up-load and download. Uses one wire
pair, with no analog phone on the line. Faster than normal ISDN. IDSL;
Basic Rate ISDN can run up to 18,000ft at 144 Kbps.]
ISDN [Integrated Services Digital Network] is a communication
standard for sending Voice, Video, and Data over digital or analog
telephone lines. Basic Rate (BRI) ISDN consists of two 64-Kbps B-channels
and one D-channel for transmitting control information. Primary Rate ISDN
consists of 23 B-channels and one D-channel [U.S.] or 30 B-channels and
one D-channel [Europe]. The ISDN 64kps rate is based on sampling analog
voice lines at 8000 times per second with 8 bits per sample. The 64Kbps
channels are called B channels. The 16Kbps channels are called D
channels. ISDN is a switched, end-to-end network that allows for
simultaneous transmission. With two full duplex digital channels, Basic
Rate Interface (BRI) ISDN provides high-speed. 128 kilobits per second
(kbps) is typical, up to 512kbps with compression. Primary Rate Interface
(PRI) ISDN bundles twenty-three channels together, to provide speeds of
up to 1,544 kbps.
Related; Ethernet-over-VDSL (EoVDSL)
ITU {International Telecommunication Union}
ETSI {European Telecommunications Standard Institute}
Analog Devices {DSL Products}
Broadcom Corp. {DSL-ADSL/VDSL IC
Manufacturer}
Centillium Communications,
Inc.
Intersil {ADSL xceviers}
Legerity {ADSL-Voice over
IP/DSL/VoB-SLIC-CODEC Filter}
LSI Corporation {DSL
Products}
Texas Instruments {DSL Line
Drivers/Receiver IC Manufacturer}
Refer to Telecom Device Manufacturers {Digital/Specialized Logic}
IC Manufacturers {All other device types}
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