I install rtpproxy and config as follow, but it didn't work, is my config OK ? 

errorlog:
Jun  3 15:00:56 iZ2ze3uk97m2bfv681kyx4Z /usr/local/sbin/kamailio[28971]: ERROR: rtpproxy [rtpproxy.c:2552]: force_rtp_proxy(): incorrect port 0 in reply from rtp proxy
Jun  3 15:00:58 iZ2ze3uk97m2bfv681kyx4Z /usr/local/sbin/kamailio[28971]: ERROR: rtpproxy [rtpproxy.c:2552]: force_rtp_proxy(): incorrect port 0 in reply from rtp proxy


My config: 

PUB_IP:  public ip of kamailio
PVT_IP: private ip of kamailio

1. start rtpproxy
rtpproxy -l PUB -s udp:localhost:7722 -F

2. kamailio.cfg
#!define WITH_MYSQL
#!define WITH_AUTH
#!define WITH_ALIASDB
#!define WITH_USRLOCDB
#!define WITH_NAT

listen=PVT_IP

modparam("rtpproxy", "rtpproxy_sock", "udp:localhost:7722")

--
Best Regards,
Shengy