Dialogic Global Call IP Benutzerhandbuch

digits are detected. The events for this notification must be enabled; see 

, on page 154. 

Once the events are enabled, when an incoming DTMF digit is detected, the application receives a 
GCEV_EXTENSION event, with an extID of IPEXTID_RECEIVE_DTMF. The 
GCEV_EXTENSION event contains the digit and the method. The GC_PARM_BLK associated 
with the event contains the IPSET_DTMF parameter set ID and the following parameter ID: 

IPPARM_DTMF_ALPHANUMERIC 

For H.323, DTMF digits are received in H.245 User Input Indication (UII) alphanumeric 
messages. The parameter value is a data structure of type IP_DTMF_DIGITS (it is not a 
string). See the reference page for 

 on page 547 for more information. For 

SIP, this parameter is not supported. 

Once DTMF support has been configured (see 

page 238), the application can use the gc_Extension( ) function to generate DTMF digits. The 
relevant gc_Extension( ) function parameter values in this context are: 

target_type should be GCTGT_GCLIB_CRN 

target_id should be the actual CRN 

ext_ID should be IPEXTID_SEND_DTMF 

The GC_PARM_BLK pointed to by the parmblkp parameter must contain the IPSET_DTMF 
parameter set ID and the following parameter ID: 

IPPARM_DTMF_ALPHANUMERIC 

For H.323, specifies that DTMF digits are to be sent in H.245 User Input Indication (UII) 
Alphanumeric messages. For SIP, this parameter is not supported. 

Using a voice resource to generate or detect DTMF tones in Inband or RFC2833 DTMF transfer 
mode requires that the voice resource (for example, dxxxB1C1) be attached to the IPT network 
device (for example, iptB1T1) that also has an IP Media device (ipmB1C1) attached. This can be 
achieved using the gc_OpenEx( ) function as follows: 

gc_OpenEx(lindevice, ":P_IP:N_iptB1T1:M_ipmB1C1:V_dxxxB1C1", EV_ASYNC, userattr) 

where:

linedevice is a Global Call device 

P_IP indicates that the device supports both the H.323 and SIP protocols 

N_iptB1T1 identifies the IPT network device 

M_ipmB1C1 identifies the IPT Media device 

V_dxxxB1C1 specifies the voice resource that will be used to generate or detect the DTMF 
tones