[OpenSER-Users] newbie question on NAT

Hi, I am working on configuring RTP Proxy. The problem I am having is that Openser will use rtp proxy to serve the rtp session even when both UAs and Openser are withing the same LAN. Here is the openser.cfg I used: if (nat_uac_test("19")) { if (method=="REGISTER") { fix_nated_register(); } else { fix_nated_contact(); }; setflag(5); }; Hre is a INVITE SIP packet from one of the UA: U 192.168.1.101:5062 -> 192.168.1.104:5060 INVITE sip:1006@192.168.1.104 &lt;sip%3A1006(a)192.168.1.104&gt; SIP/2.0..Via: SIP/2.0/UDP 192.168.1.101:5062;branch=z9hG4b K-220120f9..From: "1005" <sip:1005@192.168.1.104<sip%3A1005@192.168.1.104>>;tag=490c5d623d5acbf5o0..To: "1006" <si p:1006@192.168.1.104 <p%3A1006@192.168.1.104>>..Call-ID: 3e5720e1-bf774681@192.168.1.101..CSeq: 102 INVITE..Max-F orwards: 70..Proxy-Authorization: Digest username="1005",realm=" 192.168.1.104",nonce="48 4b3b51ea052f45482ef4fd26f00a14239c3465",uri="sip:1006@192.168.1.104<sip%3A1006@192.168.1.104> ",algorithm=MD5,respo nse="d46ea7cd9781b9a1493e6eaf7b978086",qop=auth,nc=00000001,cnonce="676aa6d8"..Contact: "1005" <sip:1005@192.168.1.101:5062>..Expires: 240..User-Agent: Sipura/SPA921-4.1.10(b). .Content-Length: 401..Allow: ACK, BYE, CANCEL, INFO, INVITE, NOTIFY, OPTIONS, REFER..Con tent-Type: application/sdp....v=0..o=- 26093424 26093424 IN IP4 192.168.1.101..s=-..c=IN IP4 192.168.1.101..t=0 0..m=audio 16474 RTP/AVP 0 2 4 8 18 96 97 98 101..a=rtpmap:0 PCM U/8000..a=rtpmap:2 G726-32/8000..a=rtpmap:4 G723/8000..a=rtpmap:8 PCMA/8000..a=rtpmap:18 G729a/8000..a=rtpmap:96 G726-40/8000..a=rtpmap:97 G726-24/8000..a=rtpmap:98 G726-16/800 0..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a=ptime:30..a=sendrecv.. # I even tested with nat_uac_test("1") and nat_uac_test("2") and nat_uac_test("16") seperately and found that nat_uac_test("1") is return true, meaning that Openser detects a RFC1918 address in the Contact field. If Openser is in the same LAN as the UA, then no rtp proxy should be utilized. Could someone please help me out to configure rtp proxy correctly? I would appreciate any help in solving this problem. Regards, Mark