Dialogic IP Phone 05-2239-009 User Manual

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Dialogic Corporation

When the Dialogic

®

 Global Call API is initialized in 3PCC mode, the call control library 

(IPCCLIB) does not internally negotiate media session parameters; the host application is 
responsible for negotiating the following:

coordinating matching audio/video coders

generating SDP data for outgoing SIP messages. These outgoing SIP messages are created 
when certain Dialogic

®

 Global Call API functions are called (as shown in 

parsing the SDP data that is attached to incoming Dialogic

®

 Global Call API events (as shown 

in 

In third party call control call flows, the host application is entirely responsible for the SDP 
contents of SIP messages. The SDP data negotiates media session parameters and connects the 
RTP media streams. The SDP data is generated and attached to outbound SIP messages. Likewise, 
SDP data is parsed from incoming Global Call events. The SDP data is then passed to and from 
host applications in IPSET_SDP parameter set IDs. 

There are many open source SDP generator/parser tools that can be used to build Dialogic

®

 Global 

Call API-based multimedia applications. The Dialogic

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 Host Media Processing (HMP) Software 

includes an example SDP generator/parser. The example is described in 

For complete information about SDP, refer to the Internet Engineering Task Force (IETF) 
document RFC 2327 - SDP: Session Description Protocol, which is available at 

This section describes the Dialogic

®

 Global Call API modifications and extensions made to 

support 3PCC mode. The topics are as follows:

The Dialogic

®

 Global Call API library supports two mutually exclusive modes of operation, first 

party call control (1PCC) mode and third party call control (3PCC) mode. The mode of operation is 
set when the Dialogic

®

 Global Call API library is initialized by calling gc_Start( ). The 

 data structure, which is passed to gc_Start( ) via the