ABSTRACT: To support new state regulations requiring Private Branch Exchange (PBX) owners to provide the location of the user at the PBX for emergency calls, PBX vendors have expressed a strong desire to be able to provide such information over an ISDN originating interface to the network (e.g., refer to T1S1/99-038, a liaison letter from TIA TR 41 to ANSI T1S1). Because of the way PBX's are designed, provisioned, and used, the PBX community has indicated that it is not sufficient to simply be able to provide the callers telephone number as the indication of the user's location. Due to mobility services (e.g., a user moving their phone from one physical location to another at the PBX), office hoteling (where a line on the PBX is temporarily used by a person who is 'hoteling' at that location), and telecommuting (where a line on the PBX is temporarily used by a person who is dialed into the PBX from home), a means of identifying the user's location was needed.

Issue 1 of GR-3023-CORE, ISDN PRI: Originating Location Information for Emergency Calls - Generic Requirements, provides generic requirements for the protocol and procedures that need to be supported by the originating switch to allow PRI Customer Premises Equipment (CPE) to provide originating location information to supplement calling party number on emergency calls. It also provides the requirements for interworking with Common Channel Signaling using Signaling System No. 7 (SS7) needed to support passing this location information forward with the call.