Dialogic 05-2239-009 User Manual
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Dialogic
®
Global Call IP Technology Guide — November 2007
Dialogic Corporation
Q.931: The Q.931 protocol defines how each H.323 layer interacts with peer layers, so that participants can
interoperate with agreed upon formats. The Q.931 protocol resides within H.225.0. As part of H.323 call control,
Q.931 is a link layer protocol for establishing connections and framing data.
interoperate with agreed upon formats. The Q.931 protocol resides within H.225.0. As part of H.323 call control,
Q.931 is a link layer protocol for establishing connections and framing data.
RTP: Real-time Transport Protocol. Provides end-to-end network transport functions suitable for applications
transmitting real-time data such as audio, video or simulation data, over multicast or unicast network services. RTP
does not address resource reservation and does not guarantee quality-of-service for real-time services.
transmitting real-time data such as audio, video or simulation data, over multicast or unicast network services. RTP
does not address resource reservation and does not guarantee quality-of-service for real-time services.
RTCP: RTP Control Protocol (RTCP). Works in conjunction with RTP to allow the monitoring of data delivery in
a manner scalable to large multicast networks, and to provide minimal control and identification functionality.
RTCP is based on the periodic transmission of control packets to all participants in the session, using the same
distribution mechanism as the data packets.
a manner scalable to large multicast networks, and to provide minimal control and identification functionality.
RTCP is based on the periodic transmission of control packets to all participants in the session, using the same
distribution mechanism as the data packets.
silence suppression: See Voice Activation Detection (VAD).
supervised transfer: A call transfer in which the person transferring the call stays on the line, announces the
call, and consults with the party to whom the call is being transferred before the transfer is completed.
call, and consults with the party to whom the call is being transferred before the transfer is completed.
UA: In a SIP context, user agents (UAs) are appliances or applications, such as, SIP phones, residential gateways
and software that initiate and receive calls over a SIP network.
and software that initiate and receive calls over a SIP network.
SIP: Session Initiated Protocol. An ASCII-based, peer-to-peer protocol designed to provide telephony services
over the Internet.
over the Internet.
split call control: An IP telephony software architecture in which call control is done separately from IP Media
stream control, for example, call control is done on the host and IP Media stream control is done on the board.
stream control, for example, call control is done on the host and IP Media stream control is done on the board.
tunneling: The encapsulation of H.245 messages within Q.931/H.225 messages so that H.245 media control
messages can be transmitted over the same TCP port as the Q.931/H.225 signaling messages.
messages can be transmitted over the same TCP port as the Q.931/H.225 signaling messages.
unsupervised transfer: A transfer in which the call is transferred without any consultation or announcement by
the person transferring the call.
the person transferring the call.
VAD: Voice Activation Detection. In Voice over IP (VoIP), voice activation detection (VAD) is a technique that
allows a data network carrying voice traffic over the Internet to detect the absence of audio and conserve bandwidth
by preventing the transmission of silent packets over the network.
allows a data network carrying voice traffic over the Internet to detect the absence of audio and conserve bandwidth
by preventing the transmission of silent packets over the network.