I have been experimenting with caller ID and my modem in visual basic. i have a program that shows all the messages received from the modem. it can connect ok, and when i dial the landline from my mobile, the visual basic program picks up that the line is being called, and displays "RING" on the screen. However, it cant display the number - the field just stays blank. is this due to NTL (out phone provider) not allowing caller ID? but surely if it was because of NTL the program wouldnt display that the line is being rung. so two things i need to know - firstly, is my line capable of this in the UK (ie have NTL allowed it), and secondly, should the number be displayed from a mobile phone (we only have the one landline, so I cant call it from another)

1 - does your modem support caller id? 2 - is caller id an extra cost option of your phone service? 3 - have someone else with caller id service call you? RING and caller id use different parts of the telephone signal. RING is the detection of the ring voltage on the line, caller id is the digital decode of the line content between the first and second ring. First you should do some research on caller id. I believe US and UK signals are different. Then determine specifically if your modem supports it. Note that on some modems you may have to enable caller id by sending the modem a configuration string. There are many free caller id programs. Search Google.

After contacting NTL, they said it is an extra (charged at £1.75/month). And my modem does support caller ID (although I'm not going to pay NTL for the service :P) Thanks