A: ATM is Asynchronous Transfer Mode. It is a wide band digital communication
system enabling fast transfer of data. Schematic diagrams and a comprehensive
technical explanation can be found on the ATM
Forum Website. More information about ATM can be found by visiting the
ATM Tutorial.
Q: What is H.323?
A: H.323, originally designed by Intel, is a local area network (LAN) standard
for Ethernet. It is now an internationally agreed protocol for the transmission
of audio and videoconferencing, and ensures compatability between
videoconferencing systems, regardless of the vendor.
Q: What is H.320?
A: H.320 is a series of audio visual communications recommendations agreed in
December 1990. The aim of this series (applied to audio visual communications
between 56/64 Kbps and 2.048 Mbps channels, is to ensure that videoconferencing
systems and terminals can interconnect across any network. H.320 is the
standard that covers all of these recommendations.
Q: What is T.120?
T.120 is another internationally agreed protocol - for the transmission of
multi-media data. It can work on a number of networks including ISDN, B-ISDN,
PSTN and LAN.
Q: What is ISDN?
A: ISDN stands for Integrated Services Digital Network.
Q: How does ISDN work?
A: ISDN uses the existing public telephone network infrastructure but uses
upgraded switching to ensure digital capabilities. Using two lines (ISDN2)
gives additional bandwidth to enable videoconference systems to function at
around 15 frames a second (fps). Broadband ISDN configured at ISDN2, ISDN6 or
ISDN30 is a communication channel having a bandwidth greater than a voice-grade
channel 1 and therefore capable of high speed data transmission. Here is the
ISDN Technical FAQs Website
Q: How does ADSL work?
A: ADSL stands for Asymmetric Digital Subscriber Loop. An excellent resource
offering technical and operational information is available from
Tampere University of Technology in Finland.
Page last updated 4 May, 2005