I have one SIP client registered in yate server. All calls from it routed to h.323 trunk to avaya IP office 500. I want to use avaya conference feature thats why i need to send FLASH key to avaya via h.323 trunk. RFC 2833 declares that FLASH signal has code 16 but there is no flash key on my software client. All digits [0-9*#] transfeers correctly. Is there any solution of my problem? May be using yate javascript engine.