RADVision L2W-323, User Manual

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Glossary
Glossary-6
PBX
Private Branch Exchange. A private telephone switching system in an organization that
interconnects telephone extensions to each other and to the public telephone network.
PPP
Point-to-Point Protocol. A data link protocol that provides dial-up access over point-to-point
links. It can run on any full-duplex link from POTS to ISDN to high-speed lines (T1, T3,
etc.).
PRI
Primary Rate Interface to an ISDN network. In the U.S. a PRI line provides 23B channels
and one 64 Kbps D channel (23B+D), that is equivalent to a T1 line and in Europe, a PRI
line provides 30B channels and 1D channel (30B+D), equivalent to an E1 line.
PSTN
Public Switched Telephone Network. The worldwide telephone network.
RAS
Registration Admission Status protocol. The communication protocol used to convey
registration, admission and status messages between H.323 endpoints and the Gatekeeper.
RJ-45
Registered Jack-45. Standard 8-wire connectors for IEE 802.3 10/100Base-T networks.
room system
H.320-based legacy videoconferencing stations. They are called room systems because they
are usually large monitors with a wide-angle camera and served groups of people who meet
in a room and conference with other similar groups at remote locations.
service
A Gateway service is the mechanism that allows a LAN endpoint to choose the type of
connection it wants to establish with a terminal or telephone on a circuit-switched network.
socket
Unique transport address for an application or device formed by the IP address and port
number.
subnet
A portion of an IP network defined by a subnet mask. Devices on the same subnet have the
same subnet mask.
T1
The European interface for PRI ISDN lines. An E1 connection has up to 30 B channels and
1 D channel, which transmits at rates of up to 2.048 Mbps.