--- chan_sip.c-orig	2005-05-10 13:17:45.000000000 +0200
+++ chan_sip.c	2005-05-10 13:24:24.000000000 +0200
@@ -2141,7 +2141,7 @@
 	switch(condition) {
 	case AST_CONTROL_RINGING:
 		if (ast->_state == AST_STATE_RING) {
-			if (!ast_test_flag(p, SIP_PROGRESS_SENT) ||
+			if (ast_test_flag(p, SIP_PROGRESS_SENT) ||
 			    (ast_test_flag(p, SIP_PROG_INBAND) == SIP_PROG_INBAND_NEVER)) {
 				/* Send 180 ringing if out-of-band seems reasonable */
 				transmit_response(p, "180 Ringing", &p->initreq);