Dialogic Global Call IP Benutzerhandbuch
104
Dialogic
®
Global Call IP Technology Guide — November 2007
Dialogic Corporation
IP Call Scenarios
3.4.6
Receiving a Request to Switch From T.38 Fax to Audio
In a fax session, when a fax completes, the application can receive a request to switch from a T.38
fax session back to an audio session. The application can choose to accept the request after
disassociating the T.38 Fax device from the Media device. When Dialogic
fax session back to an audio session. The application can choose to accept the request after
disassociating the T.38 Fax device from the Media device. When Dialogic
®
Global Call API
notifies the application that the audio session has been reestablished, the application can once again
send and receive audio. Figure 45 shows the scenario diagram.
send and receive audio. Figure 45 shows the scenario diagram.
Note:
The application must not use both Dialogic
®
Global Call API and Dialogic
®
IP Media Library API
functions on the same device. The Dialogic
®
IP Media Library API calls (ipm_) in Figure 45 are
shown for informational purposes only. Global Call interacts with the IP Media Library on behalf
of the application.
of the application.
Figure 45. Receiving a Request to Switch From T.38 Fax to Audio
IPML
Remote Device Capable of
Signaling, Audio and T.38
App
gc_OpenEx(:N_iptB1T1:M_ipmB1C1)
REINVITE/RequestMode to switch to audio.
Receive IP address and RTP Port number
200OK/RequestMOde Ack
FAX
Fx_open(dxxxB23C1)
dev_Disconnect(ipmB1C1, dxxxB23C1)
Ipm_StartMedia()
T.38 Data via RTP
Fx_Recvfax()
GC/cclib
gc_MakeCall()
GCEV_CONNECTED
GCEV_EXTENSION(IPSET_SWITCH_CODEC,IPPARM_T38_REQUESTED)
gc_SetUserInfo(IPSET_FOIP,IPPARM_T38_DISCONNECT)
Fx_Stopch()
Audio Data
GCEV_EXTENSION(IPSET_SWITCH_CODEC,IPPARM_READY)
Audio Data
gc_SetUserInfo(IPSET_FOIP,IPPARM_T38_CONNECT)
GCEV_EXTENSION(IPSET_SWITCH_CODEC,IPPARM_READY)
GCEV_EXTENSION(IPSET_SWITCH_CODEC,IPPARM_AUDIO_REQUESTED)
gc_Extension(IPSET_SWITCH_CODEC,IPPARM_ACCEPT)*
Ipm_GetLocalMedia()
*Note: Alternatively, application can reject by calling
gc_Extension(IPSET_SWITCH_CODEC, IPPARM_REJECT)
with reason. Appropriate H323/SIP message will be
sent to remote side. Remote GC application receives a
GCEV_TASKFAIL event with the reason
gc_Extension(IPSET_SWITCH_CODEC, IPPARM_REJECT)
with reason. Appropriate H323/SIP message will be
sent to remote side. Remote GC application receives a
GCEV_TASKFAIL event with the reason
Ipm_Stop()
GCEV_EXTENSIONCMPLT
gc_Listen()
gc_SetConfigData(IP_MANUAL_MODE)