Dialogic Global Call IP Benutzerhandbuch

320

Dialogic Corporation

Dialogic

®

 Global Call API support for T.38 Fax Server is described under the following topics: 

 

 

 

 

 

Dialogic

®

 Global Call API provides T.38 fax server functionality to support fax-on-demand and 

other applications. The functionality includes the ability of an application to: 

initiate and complete a T.38 session without an audio connection being first established 

switch coders from audio to T.38 fax and back again during a pre-established audio connection 

To support T.38 fax functionality, Dialogic

®

 Global Call API uses two types of media devices:

a traditional Media device 

a new T.38 Fax device 

By default, ipmBxCy represents the media device on board x and channel y, which has no fax 
capability on HMP. By associating the corresponding voice handle with a fax handle, the ipmBxCy 
device represents the fax channel defined by the fax handle, with no voice capability. 
Disassociating the voice and fax devices restores the ipmBxCy device voice capability. 

The Dialogic

®

 Global Call API uses the gc_SetUserInfo( ) function to associate and disassociate a 

traditional Media device with a T.38 Fax device when establishing or concluding a T.38 fax 
connection. Manual device association must be done before the next Dialogic

®

 Global Call API 

function that requires fax information: 

For H.323, the association must be made before gc_MakeCall( ) on the outbound call side, 
and gc_CallAck( ), gc_AcceptCall( ) and gc_AnswerCall( ) on the inbound call side, 
whichever occurs first since the underlying “open logical channel” can happen at any of these 
times if coder capabilities and fax port information is available.