Attendant console: The larger, specialized
phone an operator or attendant uses to answer incoming calls and route
them to the appropriate extension. In an IP PBX, this may be replaced
by software running on a PC.
Centrex: A traditional business telephone
service that a local telephone company offers from a local central office.
This is essentially a normal single-line telephone service with advanced
CSU/DSU (channel service unit/data service unit):
A device that terminates a digital channel. In this context, the device
sits between the voice T1 line and the IP PBX.
Find-me/follow-me: A feature that allows
calls to find you wherever you are, ringing multiple phones (such as your
cell phone, home phone, and work phone) all at once. Such presence features
are found in IP PBXs and offered by some hosted services. You activate
them by pressing a soft key.
Gateway In VoIP systems: a network device
that converts voice and fax calls in real time from a public switched
(PSTN) to an IP network: A gateway can
also convert calls between branch offices to VoIP so they can travel over
High-availability: Refers to devices
or deployment strategies designed to provide access to fully functioning
systems at all times. One HA strategy is to cluster devices so that the
primary device can fail over to the secondary one if necessary.
IP Centrex or hosted voice: An IP voice
service delivered by an IP service provider or a phone company. On the
surface it is like old-fashioned Centrex, but the features are much richer
and the price is usually much lower.
IP PBX (Internet Protocol private branch exchange):
A private telephone switching system that performs the same basic functions
as a traditional PBX but operates using IP, making it easier to add features.
KTS (key telephone system): A system
in which the telephones have multiple buttons representing separate phone
lines. Users select external phone and intercom lines directly through
these buttons. KTS solutions are less expensive and less flexible than
PBX (private branch exchange) A private
telephone switching system that connects outside phone lines from a telecommunications
provider to extensions within a building or office, as well as providing
such features as call forwarding and paging. Where older proprietary systems
used handsets designed specifically for separate systems, new PBX devices
PoE (Power over Ethernet): A solution
in which networking hardware transmits electrical power over Category
5 Ethernet cable or better. This eliminates the need for AC power cords,
minimizing cabling and outlet requirements.
POTS (plain old telephone service):
The typical, familiar single-phone-line-and-single-phone-number model.
PSTN (public switched telephone network) The combination of local, long-distance,
and international carriers that make up the worldwide telephone network.
QoS (quality of service): The ability
of a network (including applications, hosts, and infrastructure devices)
to deliver traffic with minimum delay and maximum availability.
SIP (Session Initiation Protocol): An
Internet Engineering Task Force (IETF) standard for initiating, maintaining,
and terminating an interactive user session involving video, voice, chat,
gaming, virtual reality and more.
Soft keys: Buttons on a telephone handset
that can be programmed to perform various functions—such as speed
dialing or conferencing—depending on the interface on the handset's
Soft phone: IP telephony software that
lets users send and receive calls from non-dedicated hardware such as
a PC or Pocket PC device. It is typically used with a headset and microphone.
VoIP (Voice over IP):The process of
making and receiving voice transmissions over any IP network. IP networks
include the Internet, office LANs, and private data networks between corporate
offices. The main advantage of VoIP is that users can connect from anywhere
and make phone calls without incurring typical analog telephone charges,
as for long distance.