scope:

Scope and purpose

This standard specifies the service capabilities of the Call Hold service within the context of an Integrated Services Digital Network (ISDN). The Call Hold service allows a served user to interrupt B-channel communications on an existing call and then subsequently, if desired, re-establish communications. The associated switching and signaling specifications are also provided. This service may be made available on demand or in a subscription arrangement. The interaction of this service with other service capabilities defined in American National Standards is also included. The purpose of this standard is to allow maximum compatibility among public-, and user-owned telecommunications equipment in order to increase the attractiveness and usefulness of ISDN-based capabilities.