ABSTRACT: This document describes the switching and signaling procedures for the Local Exchange Carrier (LEC) side of an ISDN PRI that connects to an InterExchange Carrier (IEC) switch.

This document addresses the following features and capabilities: call control, access to Business Group Dialing Plan (BGDP) options and restrictions, Calling Number Identification Services, Calling Name Identification Services, specific IEC capabilities and services including call-by-call services defined by the IEC, and exchange of private networking information (e.g., originating line information and user entered code). Possible interface configurations may include a single DS1 using Facility Associated Signaling (FAS), multiple DS1 using Non-Facility Associated Signaling (NFAS), and multiple DS1s using NFAS with D-channel backup.

This document assumes that the LEC side of the PRI is a member of a Business Group and supports the PRI user-side requirements described in GR-2985. Switching and signaling requirements for the IEC switch are beyond the scope of this document. Where appropriate, assumptions made about the IEC switch are stated.