ANSI T1.621-1992 (R1999)

User to User Signaling Supplementary Service Description

The user-to-user signaling supplementary service provides a means of communication used to exchange user information between two users. The exchange of user information is generally not a network acknowledged service. Acknowledgment of receipt of user information is not the responsibility of the network. Network notification of user information discard, due to the network's inability to transport the user information, shall be limited to notification sent to the user originating the discarded user information. This standard is one of a series which defines and describes service capabilities within the context of an Integrated Service Digital Network (ISDN). It describes a single service capability which is a telecommunication transport capability. Such capability may be made available on a demand or a subscription arrangement. The interaction of this service capability with other ANSI defined service capabilities is also included. The purpose of the standard is to allow maximum compatibility among network and user owned telecommunications equipments in order to increase the attractiveness and usefulness of ISDN-based capabilities.