ISO/IEC 23289:2002 PDF

Overview

ISO/IEC 23289:2002 specifies signalling interworking between QSIG and H.323 to support basic services within a corporate telecommunication network. It defines how a gateway should map and translate call control and supervision messages so that a Private Integrated Services Network (PISN) using QSIG can interoperate with a private IP network using H.323. The standard covers bidirectional basic services for speech, DTMF, facsimile and modem media, and focuses on signalling and call establishment - not on media transport protocols inside the IP network or supplementary services.

Keywords: ISO/IEC 23289:2002, signalling interworking between QSIG and H.323, QSIG-H.323 gateway, corporate telecommunication networks.

Key topics and requirements

• Architecture and roles: Gateway appears as a PINX on the PISN side and an H.323 endpoint on the IP side. Supports gatekeeper registration and optional gatekeeper-less operation.
• Supported protocols: Interworking between QSIG (as defined in ISO/IEC 11572) and H.323 family protocols - notably H.225.0 (RAS and call control) and H.245.
• Call establishment mapping: Detailed requirements for mapping call setup, alerting, connect, progress and call clearing messages between QSIG and H.225.0/H.245.
• Media considerations: Specifies requirements for establishing user audio connections and support for basic media (speech, DTMF, Group 3 fax, modem). RTP/codec selection inside IP networks is out of scope.
• Numbering and addressing: Rules for mapping numbers and handling presentation/screening indicators and subaddresses.
• Validation and error handling: Gateways must validate QSIG and H.225.0 messages and prevent protocol errors from being forwarded.
• Security and conformance: Reference to H.235 for security considerations; conformance assessed via an Implementation Conformance Statement (ICS) (Annex A).
• Out of scope: Supplementary services, interworking with public IP networks (unless supplemented by additional functions), and special tunnelling cases.

Applications and who uses it

• Gateway and PBX vendors implementing QSIG↔H.323 gateways for enterprise deployments.
• Network architects and telecom integrators designing hybrid circuit/packet corporate networks, PBX-to-VoIP endpoint bridging, and phased VoIP migration strategies.
• Enterprise telecom teams ensuring interoperability between legacy PISN/PBX infrastructure and H.323-based softphones/gateways.
• Testing and certification labs verifying conformance to the ICS and message mapping requirements.

Practical benefits include enabling calls between legacy PBX users and IP-based endpoints, maintaining basic service interoperability during VoIP migration, and providing a standards-based blueprint for gateway behavior.

Related standards

• ISO/IEC 11572 (QSIG call control)
• ISO/IEC 11579-1 (PISN reference configuration)
• ISO/IEC 21409 (QSIG/H.323 supplementary services framework)
• ITU‑T H.225.0, H.245, H.323 and H.235 (call signalling, control and security)

For deployments that require supplementary services or public-IP interworking, combine ISO/IEC 23289:2002 with the relevant functional standards and security/number-translation components.