Polycom DOC2585A Getting Started Manual page 160

Chapter A-Glossary
A-6
Abbreviation/
Explanation
Term
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). For more information,
see 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.
SRTP Encryption of SIP Media is supported using SRTP
(Secured Real-time Transport Protocol) and the AES key
exchange method.
T1 Line A 1.5Mb 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.
Whiteboard An on-screen shared notebook for placement of shared
documents.