RADVision MCU-323, User Manual

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Glossary
5
MP
Multipoint Processor – a unit that performs the call processing tasks for a multipoint
videoconference.
Multicast
In packet-switched networks, the data is sent to multiple users connected to the network or
network segment. Multicast is a one-to-many transmission similar to broadcasting, except
that multicasting implies sending to a list of specific users, whereas broadcasting implies
sending to everybody.
Neighbor Gatekeeper
The gatekeeper of a neighboring zone.
Packet-switched
Networks that break up a message into smaller packets before switching the packets to their
required destination. Each packet contains a destination address so all packets in a single
message do not have to travel by the same path. The destination computer reassembles the
packets back into their proper sequence.
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.).
Prefix
Part of the dialing sequence used to define a service.
PRI
Primary Rate Interface to an ISDN network. In the U.S. a PRI line provides 23B channels
and one 64Kbps 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.
QCIF
Quarter Common Intermediate Format – A standard video format used in
videoconferencing. QCIF is defined as one quarter the screen resolution of CIF, or 176 x
144 pixels.