[SR-Users] how to always use rtpproxy-ng and rtpengine to relay rtp packets

hi, kamailio 4.1.5 is used with rtpengine, whose older counterpart is rtpproxy-ng. I made some changes based on the default configuration files(i.e. kamailio.cfg), so that rtpproxy-ng module is enabled. Kamailio.cfg has been uploaded. In kamailio.cfg, there is one route block related to rtpproxy, i.e. route[NATMANAGE], where rtpproxy_manage("co") is called. Sometimes, rtpproxy-ng can insert new ip:port candidates in SDP. But in some case, rtpproxy-ng doesn't rewrite SDP, so rtpengine doesn't relay rtp packets at all. How to setup kamailio.cfg, so that rtpproxy-ng moudle can always rewritten new ip:port candidates, and rtpengine always relays rtp packets? Looking foreward to your reply. Thanks! B.R. Andrew