wild guess

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@2570 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/mod/endpoints/mod_sofia/mod_sofia.c

@@ -550,7 +550,11 @@ static switch_status_t sofia_on_hangup(switch_core_session_t *session)
 
 	if (tech_pvt->nh) {
 		if (!switch_test_flag(tech_pvt, TFLAG_BYE)) {
-			nua_bye(tech_pvt->nh, TAG_END());
+			if (switch_test_flag(tech_pvt, TFLAG_ANS)) {
+				nua_bye(tech_pvt->nh, TAG_END());
+			} else {
+				nua_cancel(tech_pvt->nh, TAG_END());
+			}
 		}
 		nua_handle_bind(tech_pvt->nh, NULL);
 		nua_handle_destroy(tech_pvt->nh);