[SR-Users] Not getting packets between peers!

Problems getting audio when call from outside mi LAN. Both peers in my LAN perfect. One peer in my LAN, and another outside in the cellphone company internet; the one outside don't delivery any packet to the one inside my LAN Them can see each other and try to talk but the packets sended to the other party get lost. No one receive anything. Restarting services for rtpproxy and kamailio after every try. Here is my configuration on /etc/default/rtpproxy file: USER=kamailio GROUP=kamailio CONTROL_SOCK="unix:/var/run/rtpproxy/rtpproxy.sock" EXTRA_OPTS="-l 72.28.208.16 -s udp:localhost:7722" Here my configuration on kamailio.cfg file corresponding with NAT: #!ifdef WITH_NAT # ----- rtpproxy params ----- #modparam("rtpproxy", "rtpproxy_sock", "udp:127.0.0.1:7722") modparam("rtpproxy", "rtpproxy_sock", "unix:/var/run/rtpproxy/rtpproxy.sock") # ----- nathelper params ----- modparam("nathelper", "natping_interval", 30) modparam("nathelper", "ping_nated_only", 1) modparam("nathelper", "sipping_bflag", FLB_NATSIPPING) modparam("nathelper", "sipping_from", "sip:pinger@kamailio.org") # params needed for NAT traversal in other modules modparam("nathelper|registrar", "received_avp", "$avp(RECEIVED)") modparam("usrloc", "nat_bflag", FLB_NATB) #!endif Ports opened in my router for Kamailio: udp:35000-65365, udp-tcp:5060, 5061 I know this is personal information but this server is a case study. I'm Trying to learn from you all and if it's possible contribute in the future with some knowledge. Two users for you to test: user name: support domain: uscallfree.com password: support Not TLS yet user name: master domain: uscallfree.com password: master Not TLS yet If one of you wants to try what happen when calls from one peer use that one above, my user name always active is admin(a)uscallfree.com. I know it's not working but maybe helps to determine what it's happening. admin(a)uscallfree.com active 24 hrs. in my nexus 4 native SIP profile configuration. Thank for the help provided here in the mailing list. You all rocks