MGC Manager User’s Guide - Volume I
B-7
Port One of 23 channels in a T1 PRI; one of 24 channels in a
T1 leased line; or one of 30 channels in an E1 PRI.
POTS Plain Old Telephone System. Conventional analog
telephone line.
PRI Priority Rate Interface. An ISDN interface designed for
high volume data communication. Consists of 23 B
channels of 64 Kbps each and one D channel of 64 Kbps.
In Europe, the PRI line provides 30 B channels + one D
channel.
QCIF Quarter CIF. A video format with image size of 176x144
pixels that transmits 9.115 Mbps at 30 frames per second
(a quarter of the capacity of CIF). See also CIF.
QoS Quality of Service. QoS defines the performance of a
network service, such as the average delay between
packets.
RS-232 A standard for serial interface connection.
SIP Session Initiation Protocol. An application-layer protocol
designed to work over IP networks. A SIP service defines
the properties and the IP addresses of the SIP network
components.
Span An ISDN line or leased line. A span may be of either T1
(United States) or E1 (Europe) type. Also called a circuit.
Switched 56 line A line using protocols pre-dating the ISDN protocols; also
called a robbed bit signaling line or a pre-ISDN line.
T.120 A standard for data and application sharing. Users can
share and manipulate data as if they were in the same
room.
T1 Line An 1.5 Mb digital switched line used in the United States.
ToS Type of Service. Tos defines optimization tagging for
routing audio and video packets.
WAN Wide Area Network. A communications network that
services a geographical area larger than the LAN.
Abbreviation/
Term Explanation