Nortel Networks CTA 500dm - Manual (Page 63)

AT commands 63
P0873832 Issue 05 CTA 500 dm On Line Guide
returns an ASCII string containing the calling line ID information.
This command is valid only during incoming calls and is
independent of the Calling Line ID Delivery Control.
If the calling line ID is unknown, the returned string is UNKNOWN.
There is no numeric form to the UNKNOWN string. If the calling
line ID is known, it is returned as a single text string, as in the
concatenated format of the Calling Line ID Delivery Control.
Result Codes
OK Appears when the calling line request is valid.
ERROR Appears when the command could not be completed; for
example, when there is no incoming call.
Note: The absence of calling line ID information is not an error
condition.
Caller ID Security
Caller ID security provides either call screening or call blocking
based on a list of numbers entered by the user. Call screening accepts
calls from numbers that are on the list while call blocking accepts
calls from numbers that are not on the list. If Caller ID security is
disabled all calls are accepted.
The Caller ID security list holds up to ten numbers with a maximum
length of 13 digits. You can use Т?У as a wild card character.
Incoming calls are compared to the numbers in the list, from right to
left, and accepted or blocked as applicable. For instance, a stored
number of Т535?8У will accept calls from Т5-3538У and Т5-3578У
but not from Т5-3523У.
Note: Call screening and call blocking cannot be enabled
simultaneously.