Cisco Cisco Computer Telephony Integration Option 8.5 Technical References

 defines the complete CTI server message set. The messages are described in greater detail in 

the remainder of this document. The length of the largest possible message (including the message 
header) defined by this protocol is 4329 bytes.

1

FAILURE_CONF

Negative confirmation; may be sent in 
response to any request.

2

FAILURE_EVENT

Unsolicited notification of a failure or error.

3

OPEN_REQ

Communication session establishment 
request.

4

OPEN_CONF

Communication session establishment 
confirmation.

5

HEARTBEAT_REQ

Communication session maintenance request.

6

HEARTBEAT_CONF

Communication session maintenance 
confirmation.

7

CLOSE_REQ

Communication session termination request.

8

CLOSE_CONF

Communication session termination 
confirmation.

9

CALL_DELIVERED_ EVENT

Notification of inbound call arrival.

10

CALL_ESTABLISHED_ EVENT

Notification of answering of inbound call.

11

CALL_HELD_EVENT

Notification of call placed on hold.

12

CALL_RETRIEVED_ EVENT

Notification of call taken off hold.

13

CALL_CLEARED_ EVENT

Notification of call termination.

14

CALL_CONNECTION_ 
CLEARED_EVENT

Notification of the termination of a conference 
party connection.

15

CALL_ORIGINATED_ EVENT

Notification of outbound call initiation.

16

CALL_FAILED_EVENT

Notification of inability to complete call.

17

CALL_CONFERENCED_ EVENT

Notification of tandem connection of two 
calls.

18

CALL_TRANSFERRED_ EVENT

Notification of call transfer.

19

CALL_DIVERTED_ EVENT

Notification of call changing to a different 
service.

20

CALL_SERVICE_ INITIATED_ EVENT

Notification of the initiation of 
telecommunications service at a device 
(“dial-tone”).

21

CALL_QUEUED_EVENT

Notification of call being placed in a queue 
pending the availability of some resource.

22

CALL_TRANSLATION_ ROUTE_EVENT

Notification of call context data for a call that 
has been routed to the peripheral via a 
translation route.