Q.2931, based on Q.931, is a signaling protocol, which specifies the procedures for the establishment, maintenance and clearing of network connections at the B-ISDN user network interface. The PNNI and the UNI specifications are based on Q.2931. The procedures are defined in terms of messages exchanged.
Q.700, an ITU-T specification, provides an introduction to CCITT Signalling System No. 7 (SS7).
Q.703, an ITU-T specification, defines the Signalling System No. 7 (SS7) - Message Transfer Part, Signalling Link.
Q.704, an ITU-T specification, defines the Signalling System No. 7 (SS7) - Message Transfer Part, Signalling System No. 7 - Signalling Network Functions and Messages.
Q.705, an ITU-T specification, defines the System No. 7 - Signalling network structure.
Q.706, an ITU-T specification, defines the Signalling System No. 7 - Message Transfer Part Signalling Performance.
Q.712, an ITU-T specification, defines the Signalling System No. 7 (SS7) - Definition and Function of SCCP Messages.
Q.713, an ITU-T specification, defines the Signalling System No. 7 - SCCP Formats and Codes.
Q.716, an ITU-T specification, defines the Signalling System No. 7 - Signalling connection control part (SCCP) performance.
Q.725, an ITU-T specification, defines Signalling System No. 7 - Signalling performance in the telephone application.
Q.732, an ITU-T specification, provides the Stage 3 description for numbering identification supplementary services using Signalling System No. 7 (SS7).
Q.733, an ITU-T specification, provides the Stage 3 description for call offering supplementary services using Signalling System No. 7(SS7)..
Q.734, an ITU-T specification, provides the Stage 3 description for call completion supplementary services using No. 7 Signalling System (SS7).
Q.734, an ITU-T specification, provides the Stage 3 description for multiparty supplementary services using Signalling System No. 7.
Q.735, an ITU-T specification, provides the Stage 3 description for community of interest supplementary services using SS7.
Q.736, an ITU-T specification, provides the Stage 3 description for charging supplementary services using Signalling System No. 7 (SS7).
Q.737, an ITU-T specification, provides the Stage 3 description for additional information transfer supplementary services using Signalling System No. 7 (SS7).
Q.761, an ITU-T specification, provides Signalling System No.7 (SS&) – ISDN user part (ISUP) functional description.
Q.762, an ITU-T specification, defines the general function of messages and Signals of the ISDN User Part (ISUP) of Signalling System No. 7 (SS7).
Q.763, an ITU-T specification, defines the formats and codes of the ISDN User Part (ISUP) of Signalling System No. 7 (SS7).
Q.763, an ITU-T specification, defines the Signalling System No. 7 - ISDN User Part (ISUP) Signalling Procedures.
Q.766, an ITU-T specification, defines the Signalling System No.7 - Performance Objectives in the Integrated Services Digital Network Application.
Q.772, an ITU-T specification, defines the Signalling System No. 7 (SS7) - Transaction Capabilities Information Element Definition
Q.773, an ITU-T specification, defines the Signalling System No. 7 (SS7) - Transaction Capabilities Formats and Encoding
Q.774, an ITU-T specification, defines the Signalling System No. 7 - Transaction Capabilities Procedures
Q.850, an ITU-T specification, defines the usage of cause and location in the Digital Subscriber Signalling System No. 1 and the Signalling System No. 7 ISDN User Part.
Q.920, an ITU-T specification, together with Q.921, defines the ISDN UNI data link layer.
Q.921, an ITU-T specification, together with Q.920, defines ISDN user-network interface - Data link layer - General aspects.
Q.922, an ITU-T specification, defines the Link Access Procedure/Protocol (LAPF), which is an enhanced LAPD (Q.921) with congestion control capabilities for Frame Mode Services in the Frame Relay network. LADF is used in the Frame Relay network for end-to-end signaling. LAPF conveys data link service data units between DL-service users in the User Plane for frame mode bearer services across the ISDN user-network interface on B-, D- or H-channels.
Q.922A is an ITU-T specification for Frame Relay encapsulation.
Q.930, an ITU-T specification, defines the Digital Subscriber Signalling System No 1 (DSS1) - ISDN user - network interface layer 3 - General aspects.
Q.931, the network layer protocol in the telecommunication architecture, is used in ISDN for call establishment and the maintenance and termination of logical network connections between two devices. Q.931 is one of the network layer (layer 3) protocols in the telecommunication architecture specified by the ITU Q series documents Q.930 through Q.931..
Q.932, an ITU-T specification, defines the generic procedures applicable for the control of supplementary services at the user-network interface. These procedures expand on the basic call-control functions defined in Q.931.
Q.933, an ITU-T specification, defines Digital subscriber Signalling System No.1 (DSS 1) - Signalling specification for frame mode basic call control.
Q.939, an ITU-T specification, defines service indicator coding examples.
Q.93B, an evolution of ITU-T recommendation Q.931, is an ITU-T specification for signaling to establish, maintain, and clear BISDN network connections.
Q.950, an ITU-T specification, defines ISDN supplementary services.
Q.951, an ITU-T specification, provides stage 3 description for number identification supplementary services using DSS1, such as Calling line identification presentation (CLIP); Calling line identification restriction (CLIR); Connected line ID and Malicious Call Identification (MCID).
Q.952, an ITU-T specification, provides stage 3 description for additional information transfer supplementary services using DSS1 (Digital subscriber Signalling System No.1), including Diversion supplementary services and Explicit Call Transfer (ECT).
Q.953, an ITU-T specification, defines Stage 3 description for call completion supplementary services using DSS 1 such as Call waiting, Call hold, Completion of Calls to Busy Subscribers (CCBS), Terminal Portability (TP) and Call Completion on No Reply (CCNR).
Q.954, an ITU-T specification, provides the Stage 3 description for multiparty supplementary services using DSS 1, such as Conference calling and Three-party service.
Q.955, an ITU-T specification, provides Stage 3 description for community of interest supplementary services using DSS 1, such as Closed user group and Multi-level precedence and preemption.
Q.956, an ITU-T specification, defines Integrated services digital network (ISDN) - Stage 3 service description for charging supplementary services using DSS 1 such as Clause 2 - Advice of charge (AOC) and Clause 3 - Reverse charging.
Q.957, an ITU-T specification, provides Stage 3 description for additional information transfer supplementary services using DSS 1: User-to-User Signalling (UUS).
QDI: Quasi Delay Insensitive Circuits
Quasi Delay Insensitive (QDI) Circuits are those whose correct operation does not depend on the delays of operators or wires, except for certain wires that form isochronic forks.
QPSK: Quadrature Phase Shift Keying
Quadrature Phase Shift Keying (QPSK) is a digital modulation scheme that conveys data by changing, or modulating, the phase of a reference signal (the carrier wave). Sometimes known as quaternary or quadriphase PSK or 4-PSK, QPSK uses four points on the constellation diagram, equispaced around a circle. With four phases, QPSK can encode two bits per symbol, shown in the diagram with Gray coding to minimize the BER.
QRSS: Quasi-Random Signal Sequence
Quasi-Random Signal Sequence (QRSS) is a test pattern widely used to simulate voice signals.
Q Signaling(QSING) is a common channel signaling protocol based on ISDN Q.931 standards and used by many digital PBXs.
Quad Lock Conduit is the conduit to protect telephone wires intended to be buried.
Quadruple Order Tone is one of the Order Tone (See Order Tone). This signal is four short spurts in quick succession and means that the operator should pass the city name only and wait for another challenge. It is used in manual toll tandem (also called zip tones or trunk assignment tones). Quadruple-order tone is four short spurts of High Tone.
Quantizing Distortion refers to a form of distortion that causes an irregular facsimile of the original audio. It is a result of a digital signal being corrupted to a degree which occurs in the digital-to-analog translation process.
Quantizing Noise refers to signal errors which result from the process of digitizing (and therefore ascribing finite quantities to) a continuously variable signal (analog signal).
Quasi-associated Mode is a special non-associated signaling operation. In Quasi-associated Mode, the signaling message route is determined (for each signaling message) by the signaling points between two or more signaling links (in tandem) passing through one or more STPs (Signaling Transfer Part).