Dialogic Global Call IP Benutzerhandbuch
342
Dialogic
®
Global Call IP Technology Guide — November 2007
Dialogic Corporation
Third Party Call Control (3PCC) Operations and Multimedia Support
Global Call API library. The host application does not require direct access to the IP Media Library,
as shown in
as shown in
When the Dialogic
®
Global Call API library is initialized in 3PCC mode, the host application is
directly responsible for calling the Dialogic
®
IP Media Library API functions to manage RTP
streams. This relationship is shown in Figure 63. Refer to the Dialogic
®
IP Media Library API
Programming Guide and Dialogic
®
IP Media Library API Library Reference for more information
about the IPML API.
, on page 343 provides a complete
overview of the Dialogic
®
Global Call API library modifications made to support 3PCC mode.
Figure 66. Global Call over IP Architecture for Third Party Call Control Mode
5.1.3
Session Description Protocol
The session description protocol (SDP) is the method of choice for communicating device
capabilities between SIP endpoints. SDP is used to exchange endpoint capability information such
as coder support, IP address, port information and media stream direction.
capabilities between SIP endpoints. SDP is used to exchange endpoint capability information such
as coder support, IP address, port information and media stream direction.
When the Dialogic
®
Global Call API is initialized in 1PCC mode, the SDP content in SIP
messages is not exposed to the application. The call control library (IPCCLIB) controls media
negotiations internally.
negotiations internally.
Host Application
IP Media
Resource
Resource
Signaling
IP Network
DTI Network
Device
Media
IP Network
TDM
RTP/RTCP
Call Control
SIP Call
Control Library
(IPTCCLIB)
Host
Board
Media
IP Media
Library
Host
NIC
TDM
PSTN
Global Call
SDP