request-line使用fromdomain，兼容IMS

channels/chan_sip.c

@@ -14443,7 +14443,8 @@ static void initreqprep(struct sip_request *req, struct sip_pvt *p, int sipmetho
 				}
 				ast_str_append(&invite, 0, "%s@", n);
 			}
-			ast_str_append(&invite, 0, "%s", p->tohost);
+			//ast_str_append(&invite, 0, "%s", p->tohost);    //changed by dingyu; request-line use fromdomain 
+			ast_str_append(&invite, 0, "%s", p->fromdomain);
 			if (p->portinuri) {
 				ast_str_append(&invite, 0, ":%d", ast_sockaddr_port(&p->sa));
 			}