scope:

Scope and Purpose

This standard describes signaling support for Operator Services when the application providing the services resides in the NGN. The services within the scope of this standard include:

1. Directory Assistance/Directory Assistance Call Completion

2. Operator Assistance

3. Transfer to an Interexchange Carrier

4. Call Completion

5. Person Handling (Person-to-Person Call)

6. Calling Card and Commercial Credit Card (Alternate Billing)

7. Collect or Reverse Charging (Alternate Billing)

8. Third Number Billing (Alternate Billing)

Network control of a coin phone is out of the scope of this standard.

Intercept Service (providing information to the calling party regarding a number which has been disconnected or changed) is for further study.

Busy Line Verification Service (verifying for the calling party that a called number is not out of service but is busy) and Interrupt Service (bridging an operator onto an existing call between two parties to alert one of the parties that the calling party is attempting to reach them) are also for further study.

The scope of this standard includes:

1. SS7 to SIP interworking for a call originating in the PSTN and directed toward the Operator Services System (OSS) in the NGN.

2. SIP signaling for a call originating in the NGN and directed toward the Operator Services System (OSS) in the NGN.

In addition, this standard describes the signaling for establishing a call/session from the OSS to a further destination, noting the similarities to normal call/session setup signaling.

Interconnection is assumed to be between trusted domains; the information and parameters required for this service are only available either within a trust domain or between trusted domains. In addition, in the absence of trust, and depending on exactly which information is not trusted, basic call setup may not function as expected.

Signaling to establish a call/session from the NGN to an OSS in the PSTN is not addressed in this standard, though ISUP/SIP interworking as described in ANSI T1.679 [T1.679] should provide the needed functionality.