Dialogic IP Phone 05-2239-009 User Manual

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Dialogic Corporation

For incoming calls, tunneling is enabled by default, but it can be configured on a board device level 
(where a board device is a virtual entity that corresponds to a NIC or NIC address; see 

, on page 47). This is done using the gc_SetConfigData( ) 

function with target ID of the board device and the parameters above specified in the 
GC_PARM_BLKP structure associated with the gc_SetConfigData( ) function. 

Tunneling for inbound calls can be configured on a board device basis only (using the 
gc_SetConfigData( ) function). Tunneling for inbound calls cannot be configured on a per line 
device or per call basis (using the gc_SetUserInfo( ) function). 

The Dialogic

®

 Global Call API library allows applications to specify whether they wish to use 

signaling techniques that exchange media capabilities as early as possible in the call initiation 
process. In general, this “fast start” call setup is preferable to the “slow start” setup for several 
reasons:

fewer network round trips are required to set up a call

media streaming may be possible earlier in the pre-connection phase (“early media”)

the local exchange can generate messages when circumstances prevent a connection to the 
endpoint 

The selection of fast start vs. slow start mode only applies to the first party call control (1PCC) 
operating mode. If the Dialogic

®

 Global Call API library is initialized in the third party call control 

(3PCC) operating mode, the IPSET_CALLINFO / IPPARM_CONNECTIONMETHOD parameter 
that is documented in this section is not supported.

The same Global Call parameter mechanism is used to specify slow start vs. fast start mode for 
both the H.323 and SIP protocols, even though the result of the mode selection is quite different in 
the different protocols. See 

, on page 116, and 

, on page 118, for protocol-specific details on the connection 

modes.

Dialogic

®

 Global Call API applications can set either the fast or slow call setup mode as the default 

mode for the entire system or for all calls on a given line device, and can also override that default 
on a call-by-call basis. If the application takes no action to specify the setup mode, the system 
default is fast start mode. 

To specify the slow start mode, either for an individual call or as the default mode, the application 
inserts the following parameter element in a GC_PARM_BLK:

IPSET_CALLINFO

IPPARM_CONNECTIONMETHOD

value = IP_CONNECTIONMETHOD_SLOWSTART