+ mISDNSIGNAL_VOLUME, /* change volume */
+ mISDNSIGNAL_CONF, /* joint/split conference */
+ mISDNSIGNAL_JOINDATA, /* data required by join instance */
+ mISDNSIGNAL_ECHO, /* enable/disable echoe */
+ mISDNSIGNAL_DELAY, /* use delay or adaptive jitter */