Nortel Remote Gateway 9150 Installation And Administration Manual page 538

Glossary
Power-On Self-Test
Initializes and performs rudimentary tests on baseboard hardware, including
CPU, floating point unit, interrupts, memory, real-time clock, video, and
auto-initializing PCI and EISA bus.
priority DN
A user station can be configured as a priority DN. There are two levels of
priority—high and normal. High priority level allows you to
ensure a trunk is always available
use PSTN trunking for the host PBX connections
move the high priority DN first from the IP network to the PSTN
private branch exchange
A telephone switch, typically used by a business to service its internal telephone
needs. A PBX usually offers more advanced features than are generally
available on the public network. Users of the PBX share a certain number of
outside lines for making telephone calls external to the PBX.
protocol
A standard format used for communication between two devices. The protocol
determines the type of error checking to be used, the data compression method
(if any), how the sending device indicates that it has finished sending a message,
and how the receiving device indicates that it has received a message.
PSTN
Public Switched Telephone Network (also known as the public telephone
network).
Q
Quality of Service (QoS) Transitioning Technology
Technology that automatically switches calls from the IP network to the PSTN
when the voice QoS falls below a predetermined threshold, and back to the IP
network when the QoS returns to normal.
510 Remote Gateway 9150 Installation and Administration Guide
Standard 4.0