Glossary and Abbreviations
555-230-024GL-40 Issue 5 January 1998
PRI endpoint (PE)
The wideband switching capability introduces PRI endpoints on switch line-side interfaces. A PRI
endpoint consists of one or more contiguous B-channels on a line-side T1 or E1 ISDN PRI facility
and has an extension. Endpoint applications have call-control capabilities over PRI endpoints.
principal
A terminal that has its primary extension bridged on one or more other terminals.
principal (user)
A person to whom a telephone is assigned and who has message-center coverage.
private network
A network used exclusively for the telecommunications needs of a particular customer.
private network office code (RNX)
The first three digits of a 7-digit private network number.
PROCR
Processor
processor carrier
See control carrier.
processor data module (PDM)
A device that provides an RS-232C DCE interface for connecting to data terminals, applications
processors (APs), and host computers, and provides a DCP interface for connection to a
communications system. See also modular processor data module (MPDM).
processor port network (PPN)
A port network controlled by a switch-processing element that is directly connected to that PN’s
TDM bus and LAN bus. See also port network (PN).
processor port network (PPN) control carrier
A carrier containing the maintenance circuit pack, tone/clock circuit pack, and SPE circuit packs
for a processor port network (PPN) and, optionally, port circuit packs.
Property Management System (PMS)
A stand-alone computer used by lodging and health-services organizations for services such as
reservations, housekeeping, and billing.
protocol
A set of conventions or rules governing the format and timing of message exchanges to control
data movement and correction of errors.
PSC
Premises service consultant
PSDN
Packet-switch public data network
PT Personal terminal
PTC
Positive temperature coefficient
PTT
Postal Telephone and Telegraph