(PRI) A type of
ISDN connection. In North America and
Japan, this consists of 24 channels, usually divided into 23 B
channels and 1 D channel, and runs over the same physical
interface as
T1. Elsewhere the PRI has 31 user channels,
usually divided into 30 B channels and 1 D channel and is
based on the
E1 interface.
PRI is typically used for connections such as one between a
PBX (private branch exchange, a telephone exchange operated by
the customer of a telephone company) and a CO (central office,
of the telephone company) or IXC (inter exchange carrier, a
long distance telephone company).
(1995-01-18)