ABSTRACT: This document replaces TR-TSY-000858.

GR-858-CORE includes additional requirements to support National ISDN Enhancement #105, Support of Multiple Simultaneous Conferences from a Single TEI. Clarifications are provided regarding the use of cause values (e.g., use of national-standardized values instead of network-specific values, where applicable). Clarifications are also provided regarding interactions with EKTS based on industry input (e.g., handling of an implicit transfer request from an EKTS controller when another EKTS user is bridged on).