Cisco Cisco Computer Telephony Integration Option 9.0 Developer's Guide

Communication between the CTI client and the CTI Server is accomplished by the exchange of 
messages. Cisco’s CTI Server message set is modeled after the Computer-Supported 
Telecommunications Applications (CSTA) messaging conventions defined by the European Computer 
Manufacturers Association. CTI Server messages, in general, follow CSTA naming conventions and the 
request/confirmation and unsolicited event paradigms. However, CTI Server messages use a simpler set 
of data types than those defined by CSTA.

In the CSTA model, one party acts as a server and the other as a client. In the Cisco interface, as the 
names suggest, the CTI client takes the client role and issues requests to the ICM. The ICM CTI Server 
takes the server role, responding to requests from the CTI clients and originating unsolicited events.

This chapter provides the following information about CTI Server messages:

A list of the complete CTI Server message set 

A description of the following CTI Server message components:

Data Types

Floating Fields

Invoke IDs 

Call Event Data

The format for CTI Server failure indication messages

 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.