ABSTRACT: This document replaces TR-NWT-000505 and TA-TSY-001052.

Issue 2 of GR-505, Call Processing, replaces Issue 1.

This document presents the Telcordia view of generic requirements and objectives that apply to the processing of telecommunications calls associated with voice-band telephone service in a Stored Program Control System (SPCS). The SPCS call processing requirements apply to Time Division Multiplexing (TDM) switching systems.

This document describes the interactions between a local SPCS and a line or trunk during call processing, and explains the associated switching system actions required. It also covers the four major events that can occur in a call sequence: origination, termination, disconnect, and interruption.

Issue 2 of GR-505 includes the following:

• Updates to call processing timing based on advances in technology, and provides an introduction to call control processing in a Next Generation Network (NGN) environment.
• A discussion of the "softswitch" environment, which services are referred to as "Voice over IP (VoIP)."
• A new Appendix on NGN call processing.