3Com NBX 100 Administrator's Manual - page 561
G
LOSSARY
561
port
A computer interface capable of attachment to another device, such as a
modem for communicating with a remote terminal or, if the port is within
a hub, to a workstation.
POTS
Plain Old Telephone Service.
PPP
Point-to-Point Protocol. An addition to the Internet protocol suite to help
connect devices where dissimilar transport protocols exist. Typically used
for serial connections to the Internet.
predictive dialing
Automated dialing feature in which
CTI
software predicts when you will
end your current call, and dials the next call in advance.
pretranslator
A device that interprets and modifies a sequence of incoming digits or
transmits outgoing digits.
preview dialing
Automated dialing feature in which CTI software queues the next call to
be made but allows you to check and activate the call.
PRI
Primary Rate Interface. An ISDN service for users with large bandwidth
requirements, such as large PBX systems or high performance video
desktop conferencing systems; the ISDN equivalent of a T1 circuit.
protocol
A set of rules governing the information flow within a communications
infrastructure. A protocol typically specifies the structure of parameters
like format, timing, and error correction.
protocol converter
A device that translates between two protocols to facilitate
communications between different computers or different systems.
PSTN
Public-Switched Telephone Network. The term describes the national
telephone network.
punch-down block
Telephony term describing the connector arrangements for distributing
and connecting unshielded and shielded twisted pair wiring inside a
building. Typically found in telephone wiring closets.
Q
Q.921/931
ITU-TS “Q Series” Recommendations describing Lap-D, the Layer 2
protocol for an ISDN D-channel. See
OSI model
.