[Serusers] [ rtpproxy ] will waits for receiving at least one UDP packet ??

Hi all: in http://www.voip-info.org/tiki-index.php?page=Portaone%20rtpproxy is says rtpprxoy will waits for receiving at least one UDP packet from each of two parties participating in the call Once suc packet is received, the proxy fills one of two ip:port structures associated with each call with source ip:port of that packet and when both structures are filled in, the proxy starts relaying UDP packets between parties; is it always do so ? Cause when I have try rtpproxy with nathelper , but when i trace the etherreal log rtpproxy's behavior seems not waits for receiving at least one UDP packet from each of two parties after when receive only one part of the UA , rtpproxy directly transfering the rtp packet to another UA Can any tell me will rtpproxy wait for when both UA's first packet has received then start relay it ? Or it's behavior is really the same as the page said ? (http://www.voip-info.org/tiki-index.php?page=Portaone%20rtpproxy) Thanks Jimmy