Originating Identification presentation Restriction

Description

Originating Identification presentation Restriction (OIR) is a supplementary service standardized by 3GPP that provides the calling party with the ability to prevent their identification information (typically the Calling Party Number or SIP URI) from being presented to the called party. The service operates within the call control and session management layers of the network, intercepting and modifying the signaling messages that carry caller identification. When a user activates OIR (either per-call via a prefix or as a permanent subscription service), the network applies logic to either remove the identification from the outgoing signaling or mark it as 'presentation restricted'. This is enforced at the originating network's control nodes, such as the MSC (Mobile Switching Centre) in circuit-switched networks or the S-CSCF (Serving Call Session Control Function) in IMS (IP Multimedia Subsystem) networks. The service interacts with the HSS (Home Subscriber Server) or HLR (Home Location Register) to verify subscription data and service authorization. In the IMS architecture, OIR is implemented as an originating service within the S-CSCF, utilizing Initial Filter Criteria (iFC) to trigger the appropriate Application Server if needed for advanced logic. The restriction can be overridden in specific cases, such as emergency calls or calls to certain authorized numbers, as defined by network policy and regulatory requirements. The called party's network may also apply complementary services like Connected Line Identification Presentation (COLP) or generate privacy indicators based on the received restricted status.

Purpose & Motivation

OIR was created to address growing user privacy concerns, allowing individuals to control the disclosure of their personal contact information. Before such services, caller identification was typically always presented, which could lead to unwanted contact, harassment, or privacy breaches. The service solves the problem of involuntary information disclosure in telephony, giving subscribers autonomy over their identity. Its introduction was motivated by regulatory requirements in many regions mandating privacy options for telecommunications users. It also enables business applications, such as allowing employees to make business calls without revealing personal mobile numbers. The service provides a standardized mechanism across different network generations (circuit-switched and packet-switched/IMS), ensuring consistent privacy functionality as networks evolved.