Originating Identification Presentation

Description

Originating Identification Presentation (OIP) is a classic telephony supplementary service standardized in 3GPP that enables the presentation of the calling party's identification information to the called party. The service delivers the Calling Line Identity (CLI), which typically includes the calling party's directory number (MSISDN), and potentially additional name information, to the terminating network and user equipment. The service operates within the call control signaling, primarily in the ISDN User Part (ISUP) for circuit-switched calls and within Session Initiation Protocol (SIP) messages for IMS-based VoIP calls. For a call, the originating network validates the caller's subscription for OIP and, if allowed, includes the CLI in the initial address message (IAM) or SIP INVITE. The terminating network then checks the called party's subscription for the complementary service, Originating Identification Restriction (OIR), to determine if presentation is barred. If not barred, the information is delivered to the called party's terminal for display. The architecture involves the Home Location Register (HLR) or Home Subscriber Server (HSS) storing subscriber service data, Mobile Switching Centers (MSC) or Call Session Control Functions (CSCF) executing service logic, and the User Equipment rendering the information. The service is integral to user experience, fraud prevention, and call screening.

Purpose & Motivation

OIP was created to fulfill the basic telephony need for the called party to know who is calling before answering. This addresses privacy, security, and convenience concerns, allowing users to screen calls. Historically, this was a defining feature of digital telephony (ISDN) over analog systems. Its standardization in 3GPP ensures interoperability across global mobile networks, providing a consistent caller ID experience. It solves the problem of anonymous or unwanted calls by defaultingly presenting caller identity, while its counterpart (OIR) provides a privacy mechanism for callers. The evolution through 3GPP releases maintained this service through the transition from circuit-switched voice to IMS-based VoIP, ensuring service continuity and feature parity across network generations.