CALLER ID:

While the LT chipset is capable of supporting Caller ID display, not all modems are assembled with the necessary components - extra circuitry is required in order to display Caller ID information.

There are now 2 types of caller id: original (type 1) and call-waiting (type 2). If the phone line is not in use and you have caller id service, the modem will only be able to report caller id information if it is built with circuitry to capture the caller id information with the modem and line on-hook. Type 2 caller id data, which occurs with call waiting, is sent when the modem is in a call (off-hook), and does not require extra circuitry.

The +VCID=#command is used to control the modem's response to caller id: # may be 0, 1 or 2.  Zero (the default) disables caller id reporting. 1 enables a formatted caller id report, and 2 enables unformatted caller id report. All LT modems will accept the valid +VCID values, but type 1 caller id information will not be reported unless the modem has the appropriate circuitry to detect and decode the data.