if(!src_elm) src_elm = xbt_lib_get_or_null(as_router_lib,src,ROUTING_ASR_LEVEL);
if(!src_elm) xbt_die("Element '%s' not found!",src);
if(!src_elm) src_elm = xbt_lib_get_or_null(as_router_lib,src,ROUTING_ASR_LEVEL);
if(!src_elm) xbt_die("Element '%s' not found!",src);