For first-party call control, a CTI port device must exist in the Cisco Unified Communications Manager. Because each port can only have one active audio stream at a time, most configurations only need one line per port. A CTI port device does not actually exist in the system until you run a TAPI application and a line on the port device is opened requesting LINEMEDIAMODE_AUTOMATEDVOICE and LINEMEDIAMODE_INTERACTIVEVOICE. Until the port is opened, anyone who calls the directory number that is associated with that CTI port device receives a busy or reorder tone. The IP address and UDP port number is either specified statically (the same IP address and UDP port number is used for every call) or dynamically. By default, CTI ports use static registration.
The DND(Do-Not-Disturb) Feature applies only to CTI Ports. This feature is not applicable to CTI Route Points.
CTI Port Third Party Monitoring is available from TAPI release version 4.1
CTI Ports can be Dynamically as well as Statically Registered. By default, CTI ports take Static Registration.
CTI ROUTE POINT:
You can use Cisco Unified TAPI to control CTI route points. CTI route points allow Cisco Unified TAPI applications to redirect incoming calls with an infinite queue depth. This allows incoming calls to avoid busy signals. CTI route point devices have an address capability flag of LINEADDRCAPFLAGS_ROUTEPOINT. When your application opens a line of this type, it can handle any incoming call by disconnecting, accepting, or redirecting the call to some other directory number. The basis for redirection decisions can be caller ID information, time of day, or other information that is available to the program.
CTI Route Point cannot be used for the Intercom feature.
Also the Cisco Unified TSP does not support shared lines on CTI Route Point devices
CTI Route Points can only be Dynamically Registered.
For Outgoing calls, use CTI Port rather than Route Point as it is more effective for outgoing calls
Monitoring or Controlling CTI Route Point vs. CTI Port:
Is monitoring a Route Point any different from monitoring a CTI Port?
An app need return a label for a Route Point only, but implement all features as an Endpoint for CTI port.
CTI Port and Route Point do not support Agent Greeting. Application gets
LINEERR_OPERATIONUNAVAIL if CCiscoLineDevSpecificStartSendMediaToBIBRequest is issued
on a CTI port or Route Point.
N.B.: Cisco does not support CTI device monitoring or call control with 3rd-party devices.