Glossary (Q)
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Q.931
A telephony protocol for Call Signaling, consisting of Setup, Teardown and Disengage. Q.931 is included in the H.225.0
Recommendation.
Q.931 + H.245 ROUTED MODE
The routing of the Call Setup channel (Q.931) and the Control channel (H.245) through the Gatekeeper. As opposed to direct mode, where the Gatekeeper is not involved in routing these protocols.
See also Routed Mode
QCIF (QUARTER COMMON INTERMEDIATE FORMAT)
A standard video format used in mobile video conferencing (176
x 44 pixels), where the phone’s processing power and power consumption (and the display) limit the video resolution. QCIF also requires only a quarter of the transmission bandwidth required for CIF video resolution.
QOS (QUALITY OF SERVICE)
The ability to define a level of performance in a data and
real-time communications system. For example, ATM networks specify modes of service that ensure optimum performance for traffic, such as real-time voice and video. QoS is needed to ensure end-to-end delivery of packets to guarantee a satisfactory user experience.
QSIF
A video resolution equivalent to QQVGA. 160*120