ABSTRACT: Toll-Free Service is an example of a telephone company Number Service in which a special code, "800, 888, 877, etc.," indicates that the call requires special treatment. The digits following the code determine the routing of the call. It has become necessary to be able to route these toll-free calls to specific Interexchange Carriers (IXCs) or within the telephone company. Such routing varies depending on the arrangements made between the customer and the carriers and may include different routing based on the time of day, day of week, and location at which the call originated.

This Generic Requirements (GR) document provides information for the interconnection of Local Exchange Carriers' (LECs') Common Channel Signaling (CCS) networks with Interconnecting CCS Networks (ICNs) to support Toll-Free Service in an Intelligent Network (IN) environment. The document describes several interfaces between an ICN and the LEC network for Toll-Free Service. This document is a companion document to GR-905, Common Channel Signaling (CCS) Network Interface Specification (CCSNIS) Supporting Network Interconnection, Message Transfer Part (MTP), and Integrated Services Digital Network User Part (ISDNUP), and GR-1432, CCS Network Interface Specification (CCSNIS) Supporting SCCP and TCAP, and supplements the basic information in them for Toll-Free Service.

GR-1428 replaced TA-NWT-001428.

When using GR-1428, you may need to refer to GR-905, GR-1432, GR-246, GR-317, GR-394, and/or GR-533. You may also want to refer to TR-NWT-000444, GR-1100, GR-2901, and/or TRA-LAP.