RAM
Issue 1.0 May 2003
423
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)
on page 416.
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.
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
public network
The network that can be openly accessed by all customers for local and long-
distance calling.
pulse-code modulation
(PCM)
An extension of pulse-amplitude modulation (PAM) in which carrier-signal pulses
modulated by an analog signal, such as speech, are quantized and encoded to a
digital, usually binary, format.
QPPCN
Quality Protection Plan Change Notice
quadrant
A group of six contiguous DS0s in fixed locations on an ISDN-PRI facility. Note that
this term comes from T1 terminology (one-fourth of a T1), but there are five
quadrants on an E1 ISDN-PRI facility (30B + D).
queue
An ordered sequence of calls waiting to be processed.
queuing
The process of holding calls in order of their arrival to await connection to an
attendant, to an answering group, or to an idle trunk. Calls are automatically
connected in first-in, first-out sequence.
RAM
See
random-access memory (RAM)
on page 424.
