Ring ring! Who's calling please?

Zatni Arbi, Contributor, Jakarta

"Hello, is Sien Tauw there?" the woman on the other end said.

"I'm afraid you've got the wrong number, there's nobody by that name here," you answer politely. However, before you finish the sentence, the woman has already hung up.

It would have been a non-consequential happening, had it not turned out that the woman keeps calling your home -- sometimes at odd hours.

You soon get very annoyed, because she refuses to believe you when you tell her you moved into your house even before it had a phone line and you do not know the person she is trying to find. Worse, you also start receiving calls from other people looking for the same person.

They may be frantically trying to locate this person -- for whatever reason, but they certainly do not have the right to harass you.

If this person has given your number at random to evade some sort of responsibility, you should not be made into a helpless victim. Fortunately, at least now you have one sure way to protect yourself from people like that, who are robbing you of your peace of mind. It is called Caller ID.

Depending on where you live, you may be able to read the number of the phone used by the person calling each time your phone rings.

You will need a device -- probably one that has an LCD screen -- that will display the calling party's number even before you pick up the handset. So, the next time a prankster tries to disturb you again, you can just read to him his phone number. It can be a quite effective deterrence. PT Telkom, the state telecommunications firm, charges you an activation fee and an extra Rp 10,000 every month to use this feature.

Strangely, as of last week, information about this feature was unable to be found on PT Telkom's Web site. You can listen to prerecorded information about it by calling 147, though.

In fact, that is the number of PT Telkom's call center that you will have to dial if you want to find out whether the feature is already available in your area.

The feature, which is called KLIP ("Kenali Identitas Pemanggil," or 'Know the identity of your caller'), has been available here in Jakarta for a couple of years.

In the U.S., it was first introduced in the early to mid 1990s as a paid service. In some areas, the Caller ID system also displays the name of the person with whom the number is registered. Here in Jakarta we can only see the number.

What is interesting is that, in Taiwan, Chunghwa Telecom became one of the first telecom operators in the world to offer the feature without any additional charge.

When the feature was first introduced in the U.S., a lot of phone subscribers rejected it, saying that it infringed on their rights to privacy. However, it was the Caller ID feature that enabled investigators to quickly track down the creator of the ILOVEYOU bug in Manila almost two years ago, which had caused millions of dollars of losses across the world.

What you should know is that there are a lot of different standards of Caller ID systems in use throughout the world. Each country may implement a different standard.

Even in the same country, different operators may be using different standards, and when a call from one system is received by another incompatible system people can only see "Out of Area" in the display screen.

So, if you see a cute phone with Caller ID feature in Singapore's Sim Lim Square, do not simply buy it. Chances are that it will not work here in Indonesia, because Singapore uses a system called TR-NWT-000031, while here we use the FSK/DMTF system.

You had better buy it here rather than bring it home from your overseas trip. If you spend a little bit of time in local shopping centers, you will still be able to find equally good phone sets that will work with Telkom's system. Just make sure you ask the store to test it before you pay for it and take it home.

You can buy a phone that already comes with the Caller ID display, or a separate display device. Some of these devices have the sophistication to store the calling numbers, dial back any of the numbers, add time stamps and tell you the duration of each call.

Just remember that the information on the calling party's number is delivered to your Caller ID-capable phone device between the second and third ring. So, if you already have the feature activated for your phone line, do not pick it up after the first ring, wait until after the second. If you answer the call too early, the caller will hear a calling tone while you will hear nothing.