[SR-Users] One way audio on calls from pstn

Hello, I have kamailio installation WITH_PSTN, WITH_NAT and rtpproxy. Using following scenario: [kamailio]<-sip trunk ->[asterisk gw] <->sip trunk <-> [PSTN provider] All kamailio sip subscribers are behind nat in different networks. 1. OK. Local kamailio users can call one to other even they are on different networks behind nat. 2. OK. Outgoing calls from kamailio users to PSTN work also very well. 3. Not OK. Incoming from PSTN side calls have only one way audio. I tcpdump'ed kamailio box and found, that pstn provider sends RTP packets to kamailio IP in case of answered call. I guess that rtpproxy is not active in case of pstn call. Is it true ? I am using more less default kamailio config Could you please suggest solution ? BR, Dmitri