ITU's 160 anniversary

Committed to connecting the world

  •  
Girls in ICT day 2025

ITU-T Recommendations

Search by number:
Others:
Skip Navigation Links
Content search
Advanced search
Provisional name
Equivalent number
Formal description
Study Groups tree viewExpand Study Groups tree view

ITU-T Q.954.2 (10/1995)

عربي | 中文 | English | Español | Français | Русский
Stage 3 description for multiparty supplementary services using DSS 1 : Three-party service (3PTY)
This Recommendation defines the operation of the Digital Subscriber Signalling System No. 1 (DSS 1) for the support of the Three-Party (3PTY) supplementary service at the T or the coincident S and T reference point of the Integrated Services Digital Network (ISDN).The Three-Party supplementary service allows the user to establish, participate in, and control a three-way conversation, i.e. simultaneous communication involving the served user and two remote users.
Citation: https://handle.itu.int/11.1002/1000/3222
Series title: Q series: Switching and signalling, and associated measurements and tests
  Q.850-Q.999: Digital subscriber Signalling System No. 1
  Q.950-Q.959: Stage 3 description for supplementary services using DSS1
Approval date: 1995-10-17
Approval process:TAP
Status: In force
Maintenance responsibility: ITU-T Study Group 11
Further details: Patent statement(s)