ABSTRACT: This document details a feature of a Stored Program Control Switching System (SPCS) that provides an Interexchange Carrier (IXC) with a Signaling System Number 7 (SS7) access to Local Access and Transport Areas (LATAs) for the purpose of establishing and releasing call connections involving an IXC. The procedures in this document apply to call connections between distinct networks involving an IXC, independent of whether the connection is intraLATA or interLATA.

An SPCS having this feature may provide call connection to the IXC directly or via an Access Tandem (AT) switch that serves a given LATA (or portion thereof). An International Carrier (INC) served by this feature may provide call connection directly to the LATA or indirectly using the services of an InterLATA Carrier (IC) for intermediate call transport. Signaling is done using the SS7 protocol.

The ability of a local exchange carrier and IXC to exchange SS7 messages may allow IXCs to offer new services to their customers on an internetwork basis, and local exchange carriers to offer new services to their customers on an exchange access basis. This GR, however, focuses on the exchange of SS7 messages necessary for establishing and releasing basic voice calls involving an IXC.

Issue 8 of GR-394-CORE reflects the following changes:

• Added Appendix F which describes IMS and SS7 interworking with IMS.
• References and Glossary moved to Appendices G and H, respectively.