Polycom VIEWSTATION, User Manual

Page: 241 / 250

Glossary
© Polycom, Inc. 225 ViewStation User Guide
OPQ
PTZ Pan/Tilt/Zoom.
Pan – rotating camera to the left or right.
Tilt – rotating camera up or down.
Zoom – making image larger (telephoto) or
smaller (wide angle).
POTS or PSTN Plain Old Telephone Service or Public
Switched Telephone Network. The basic
service that supplies a single analog
telephone unit with access to the public
switched network (via the local telephone
service provider). Refers to the worldwide
voice telephone network accessible to all
those with telephones and access privileges.
Private Branch eXchange (PBX) A private telephone switching system,
usually located on a customer’s premises
with an attendant console. It is connected to
common group of lines from one or more
central offices to provide service to a number
of individual phones. Most PBXs allow
analog extensions on the system, allowing
access to special features such as
conferencing and transferring to analog
devices. A PBX connects to the telephone
lines supplied by the CO (Central Office).
QCIF Quarter CIF. A quarter of the Common
Intermediate Format = 176 X 144 pixels
QoS Quality of Service. This allows guaranteed
bandwidth and packet delivery between end
points over a packet network.