VOIP calling number / name display

What is CLI (Caller Line Identification)?
CLI (Caller Line Identification) is data that is automatically generated at the time a call is established and passed through carrier networks; and includes the called party's number, the calling party's number, the date and time of the call, the call's duration and routing. CLI facilitates efficient call management, route selection and billing and is passed between carriers to support the operation of carriage services in accordance with the Telecommunications Act 1997 (the Act).

CLI makes possible the provision of a range of products and services to customers, including Calling Number Display and calling name display (both referred to as CND). The exchange of CLI between carriers however, can also raise risks to personal privacy because of the personal information that is being exchanged.

What is CND (Calling Number Display)?
CND (Calling Number Display) means that the phone number of the service used by calling parties will be displayed automatically to customers who subscribe to CND Services. Callers may be identified by their numbers before their phone calls are answered and that their numbers may be captured by organizational users of CND and linked to databases for recognition of Callers and use of this information.

CND offers a range of service advantages for people receiving calls, such as being able to identify the source of incoming calls before picking up a receiver, keeping a log of incoming calls while away from the phone and being able to immediately return a missed call. CND offers several benefits to business users, including retaining contact numbers of callers for the purpose of future contact and providing enhanced service for existing customers, who can be immediately recognised at the time of their call.

However, CND also raises some complex problems through the risks it poses to personal privacy, where it applies to existing telecommunications networks and participation is on an opt-out basis. Callers in many situations may not wish the receiver to be able to identify their telephone number. Doctors who call patients from home, customers who call businesses but do not wish to be contacted in the future, and victims of domestic violence are some of the groups who may not want their numbers disclosed. Integrated with other technologies, CND can allow increased collection and use of personal information, without the knowledge of the consumer.

Unless you block your telephone number, your number (with date and time of the call) will be displayed on the telephone or mobile handset of the person you are calling where that person has Calling Number Display.

What is CND blocking?
Customers are allowed to block their CND, free of charge. CND Blocking means the method by which a customer prevents their CND information from being displayed to subscribers of CND Services, either permanently, or on a per-call basis.

How do I block CND?
Customers can manage their personal privacy by blocking CND. Customers who do not wish to have CND displayed to the called party can opt-out, either on a per-call or permanent basis. Customers opting out on a per call basis can prefix a call with *67. Customers opting out on a permanent basis can go to /my/toolbox/? and choose "disable CLID".

Disclosure of your Calling Line Identification
If you have call blocking or line blocking enabled on your phone line, or you have a Silent Line, your Calling Line Identification (CLI) will generally not be disclosed to third parties.

However there are some circumstances in which your CLI will always be disclosed. You cannot block CLI on calls made by you or someone else on your phone line:

• to the emergency call service (000)
• on internet dial up calls made to an Internet Service Provider (ISP) who uses a Telstra ISDN service or an 01983 access number, but only where the ISP uses the CLI for fraud prevention, billing, call management or credit control.

What should I do if my CND blocking fails?
If you become aware that your CND blocking has failed, first take up the matter with us. If the problem is not resolved, you can raise the matter with the Telecommunications Industry Ombudsman (TIO), who can investigate and help solve your complaint. You can contact the TIO on freephone 1800 062 058.