Hi All, I'm trying to send a custom NOTIFY message to a list of users that are registered with Kamailio. The procedure would be invoked via HTTP (jsonrpc/xmlrpc over HTTP).  1. Should I be looking at the t_uac_start/t_uac_dlg MI commands to accomplish this? Is this the best way to do it if the NOTIFY sent to the phones are unsolicited?  2. I tried to use the xhttp_rpc module for testing out tm.t_uac_start but kept running into 400 invalid headers. I'm not sure if there is a syntax issue. The NOTIFY example is NOTIFY sip:123@192.168.5.5 . . From:333@1.1..1\r\nTo:test@2.2.2.2 - Request URL: http://x.x.x.x/http_rpc/tm/tm.t_uac_start?arg=NOTIFY+sip%3A123%40192.168.5.… - Request Method: GET - Status Code: 400 Invalid headers Thanks for any feedback!