scope:

This standard is one of a series that defines and describes service capabilities within the context of an integrated services digital network (ISDN). This service capability may be made available on a demand or subscription arrangement. The interaction of this service capability with other service capabilities defined in other American National Standards is also included. The purpose of this 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.

The multi-level precedence and preemption (MLPP) service provides prioritized call handling service. This service has two parts - precedence and preemption. Precedence involves assigning a priority level to a call. Preemption involves the seizing of resources, which are in use by a call of a lower precedence, by a higher level precedence call in the absence of idle resources.

Application

This- standard applies to both an ISDN basic rate access and ISDN primary rate access and is intended to supplement the basic circuit mode call control procedures described in ANSI T1.607 and ANSI Tl .113. It should be used in conjunction with other American National Standards for ISDN supplementary services for a complete understanding of the interactions between this and other services.

This supplementary service is applicable to the following circuit mode bearer services:

speech;

3.1 -kHz audio (voice-band data);

64-kbit/s unrestricted (data).