How to enable Early Media?
Posted: Fri Jan 13, 2017 10:47 pm
Hello, I'm use H323plus v-1.26.5 with PTLib v-2.12.8 in my SCADA program for establishing phone communicate between dispatcher and abonents via intercom devices. I taken 'simple' sample from H323plus package for that.
My truble is as follow: when I call to some intercom device I taking one-way communication with it. 'Simple' is report about open logical channels to sending and to recieving, but recieving channel is not reachable and i'm not hearing abonent on intercom device, but abonent can hear me. When i use other program (Abto "H323 VoIP SDK") connection established normaly and i have two-way communication.
I'm examine ethernet traffic and detect so different between 'Simple' and 'Abto' connection:
- When 'Abto' is establishing connection with intercom it is sending SETUP message with "OpenLogicalChannel", "MasterSlaveDetermination" and "TerminalCapabilitySet" to remote party, further 'Abto' receive CallProceeding message and Alerting message with "terminalCapabilitySet", "terminalCapabilitySetAck" and "MasterSlaveDeterminationAck" on next step 'Abto' sending "empty terminalCapabilitySetAck MasterSlaveDeterminationAck" but remote party sending CONNECT message after that.
- When 'Simple' is establishing connection with intercom CONNECT message recieving before "empty terminalCapabilitySetAck MasterSlaveDeterminationAck".
In my research I came to the conclusion what 'Abto' use Early Media Mode but I can't find how to enable this method in 'Simple'.
PS: thanks to all who is answer and great sorry for my bad english.
My truble is as follow: when I call to some intercom device I taking one-way communication with it. 'Simple' is report about open logical channels to sending and to recieving, but recieving channel is not reachable and i'm not hearing abonent on intercom device, but abonent can hear me. When i use other program (Abto "H323 VoIP SDK") connection established normaly and i have two-way communication.
I'm examine ethernet traffic and detect so different between 'Simple' and 'Abto' connection:
- When 'Abto' is establishing connection with intercom it is sending SETUP message with "OpenLogicalChannel", "MasterSlaveDetermination" and "TerminalCapabilitySet" to remote party, further 'Abto' receive CallProceeding message and Alerting message with "terminalCapabilitySet", "terminalCapabilitySetAck" and "MasterSlaveDeterminationAck" on next step 'Abto' sending "empty terminalCapabilitySetAck MasterSlaveDeterminationAck" but remote party sending CONNECT message after that.
- When 'Simple' is establishing connection with intercom CONNECT message recieving before "empty terminalCapabilitySetAck MasterSlaveDeterminationAck".
In my research I came to the conclusion what 'Abto' use Early Media Mode but I can't find how to enable this method in 'Simple'.
PS: thanks to all who is answer and great sorry for my bad english.