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ISDN (Integrated Services Digital Network)
An international communications standards for simultaneous digital transmission
of voice, video, data, and other network services over the traditional circuits of
the public switched telephone network. ISDN supports data transfer rates of 64
Kbps (64,000 bits per second). BRI (basic rate interface) and PRI (primary rate
interface) are the two types of ISDNs. The popularity of ISDN has decreased in
areas where DSL and cable modem service is offered.
ISOC (Internet Society)
A nonprofit organization founded in 1992 to provide leadership in Internet
related standards, education, and policy. ISOC is supported by more than 90
organizational members and 26,000 individual members.
ITSP (Internet Telephone Service Provider)
A company that offers an Internet data service for making telephone calls using
VoIP. Most ITSPs use SIP, H.323, or IAX for transmitting telephone calls as IP
data packets. Customers may use VoIP phones or traditional telephones with an
analog telephony adapter (ATA).
ITU (International Telecommunication Union)
A telecommunications standards body that is guided by the United Nations. It
was founded as the International Telegraph Union in Paris on May 17, 1865.
The ITU acts as the global focal point for governments and the private sector
in developing networks and services and is comprised of more than 185 coun-
tries and produces over 200 standards recommendations annually in the areas
of information technology, consumer electronics, broadcasting, and multimedia
communications.
IVR (Interactive Voice Response)
A telephone technology that allows a caller to respond to configured voice menus
through voice and touch tone. The IVR system responds with pre-recorded audio
to further direct callers on how to proceed.
Jitter
The statistical variance of the inter-arrival times of RTP data packets. If a VoIP
device sends out one RTP packet every 20 milliseconds for an audio stream,
the packets will not necessarily arrive precisely every 20 milliseconds, so if the
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