---

    /* Create ringback tones */
    if (app_config.no_tones == PJ_FALSE) {
        unsigned samples_per_frame;
        pjmedia_tone_desc tone[RING_CNT+RINGBACK_CNT];
        pj_str_t name;

        samples_per_frame = app_config.media_cfg.audio_frame_ptime * 
                            app_config.media_cfg.clock_rate *
                            app_config.media_cfg.channel_count / 1000;

        /* Ringback tone (call is ringing) */
        name = pj_str("ringback");
        status = pjmedia_tonegen_create2(app_config.pool, &name, 
                                         app_config.media_cfg.clock_rate,
                                         app_config.media_cfg.channel_count, 
                                         samples_per_frame,
                                         16, PJMEDIA_TONEGEN_LOOP, 
                                         &app_config.ringback_port);
        if (status != PJ_SUCCESS)
            goto on_error;

        pj_bzero(&tone, sizeof(tone));
        for (i=0; i<RINGBACK_CNT; ++i) {
            tone[i].freq1 = RINGBACK_FREQ1;
            tone[i].freq2 = RINGBACK_FREQ2;
            tone[i].on_msec = RINGBACK_ON;
            tone[i].off_msec = RINGBACK_OFF;
        }
        tone[RINGBACK_CNT-1].off_msec = RINGBACK_INTERVAL;

        pjmedia_tonegen_play(app_config.ringback_port, RINGBACK_CNT, tone,
                             PJMEDIA_TONEGEN_LOOP);


        status = pjsua_conf_add_port(app_config.pool, app_config.ringback_port,
                                     &app_config.ringback_slot);
        if (status != PJ_SUCCESS)
            goto on_error;

        /* Ring (to alert incoming call) */
        name = pj_str("ring");
        status = pjmedia_tonegen_create2(app_config.pool, &name, 
                                         app_config.media_cfg.clock_rate,
                                         app_config.media_cfg.channel_count, 
                                         samples_per_frame,
                                         16, PJMEDIA_TONEGEN_LOOP, 
                                         &app_config.ring_port);
        if (status != PJ_SUCCESS)
            goto on_error;

        for (i=0; i<RING_CNT; ++i) {
            tone[i].freq1 = RING_FREQ1;
            tone[i].freq2 = RING_FREQ2;
            tone[i].on_msec = RING_ON;
            tone[i].off_msec = RING_OFF;
        }
        tone[RING_CNT-1].off_msec = RING_INTERVAL;

        pjmedia_tonegen_play(app_config.ring_port, RING_CNT, 
                             tone, PJMEDIA_TONEGEN_LOOP);

        status = pjsua_conf_add_port(app_config.pool, app_config.ring_port,
                                     &app_config.ring_slot);
        if (status != PJ_SUCCESS)
            goto on_error;

    }