The H.225.0 standard uses a variant of Q.931 to establish and disconnect H.323 sessions. An evolution of ITU-T recommendation Q.931. See also Q.931 . QAM quadrature amplitude modulation. Method of modulating digital signals onto a radio-frequency carrier signal involving both amplitude and phase coding.
Numbers indicate number of code points per symbol.
Data link layer protocol defined by IBM that allows SNA data to be transported across X.25 networks. QoS quality of service. Measure of performance for a transmission system that reflects its transmission quality and service availability. QoS parameters quality of service parameters. If any switch along the path cannot accommodate the requested QoS parameters, the request is rejected, and a rejection message is forwarded back to the originator of the request.