Manipulating Caller ID
During an outgoing call, the CLID is sent as part of the call information. CLID information includes at least one calling party number. The CLID might also include a name, a second number, and redirecting number information. You can control the information sent at the CallManager, and you can configure the gateway to control the information that shows up on caller ID. Some companies prefer that the main corporate number is displayed, rather than the actual extension of the person calling, for instance. The receiver can use CLID information in many ways, such as to route emergency services calls, so you must take this into account if you manipulate the CLID.
CLID Commands
You can manipulate caller ID information by a set of clid commands. These commands allow you to remove or change the calling party information transmitted with a call, or send it but prevent it from being displayed. clid commands apply to specific dial peers when given under dial-peer configuration mode. They apply globally when given under the voice service voip configuration mode (available in Cisco IOS Software Release 12.4(4)T and later). Not all options are available when configuring CLID in this mode. The commands include the following (those available under voice service voip are noted):
- clid network-number number Specifies the network number to be sent in the CLID information. It sets the presentation indicator to "Y" and the screening indicator to "network provided." Available in both dial-peer and voice service voip configuration modes.
- clid second-number strip Removes the original calling number from the H.225 source address field. You can also give this command on the same line as the clid network-number command. It is valid only if you have configured a network number.
- clid restrict Transmits the calling party information but sets the presentation indicator to "N" so that it is not displayed to the called party.
- clid strip [name | pi-restrict [all]] Removes the CLID number if just the clid strip command is given and sets the presentation indicator to "N." It removes the CLID name if the name option is added. To remove both the name and number, you must enter both commands separately. The pi-restrict option causes the CLID number to be stripped only when you set the progress indicator to "restricted." Adding the all keyword strips both the CLID number and name. The pi-restrict all option is available in both dial-peer and voice service voip configuration modes.
- clid substitute name Substitutes the calling number for the display name. Available in both dial-peer and voice service voip configuration modes.
Station ID Commands
You can control the caller ID information that FXS and FXO ports send with the station-id [name | number] string command. Using either the name or number keywords also enables caller ID on that port. The station-id command is typically used on FXS voice ports that are attached to a phone or fax that might originate on-net calls. The information that you configure with this command shows up as the caller ID on the device connected to the remote FXS port. You might also use this command on an FXO port to supply caller ID information if that does not come from the central office, for example:
VoiceGW(config)#voice-port 1/0/0 VoiceGW(config-voiceport)#station-id name C.P. Ryan VoiceGW(config-voiceport)#station-id number 1112223000