6.2.3 Setting RFC 2833 Mode

To set up a channel for RFC 2833 mode, do the following:

1. Open a channel using ipm_Open("ipmB1C1",NULL,EV_SYNC)
2. Set the mode via the IPM_PARM_INFO structure and ipm_SetParm( ) as shown below:

    IPM_PARM_INFO parmInfo;
    unsigned long ulParmValue = DTMFXFERMODE_RFC2833;
    parmInfo.eParm = PARMCH_DTMFXFERMODE;
    parmInfo.pvParmValue = &ulParmValue
    ipm_SetParm(chdev, &parmInfo, EV_ASYNC) 

3. Set up the RFC 2833 event payload on the transmit side as shown below:

    IPM_PARM_INFO parmInfo;
    unsigned long ulParmValue = 101;
    parmInfo.eParm = PARMCH_RFC2833EVT_TX_PLT;
    parmInfo.pvParmValue = &ulParmValue
    ipm_SetParm(chdev, &parmInfo, EV_ASYNC) 

4. Set up the RFC 2833 event payload on the receive side as shown below:

    IPM_PARM_INFO parmInfo;
    unsigned long ulParmValue = 101;
    parmInfo.eParm = PARMCH_RFC2833EVT_RX_PLT;
    parmInfo.pvParmValue = &ulParmValue
    ipm_SetParm(chdev, &parmInfo, EV_ASYNC) 

5. Optionally, you can mute or un-mute the audio data in the RTP stream using the eIPM_RFC2833MUTE_AUDIO enumeration. The default state is for muting to be ON.

Figure 4 shows a scenario diagram for setting RFC 2833 mode.

Figure 4. RFC 2833 Scenario Diagram

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