one way communication only. HELP!

1. Brekeke Product Name and version:Version 2.4.3.9 , Pro Evaluation

2. Java version:1.6.0_19

3. OS type and the version:xp pro

4. UA (phone), gateway or other hardware/software involved:xlite

5. Select your network pattern from http://www.brekeke-sip.com/bbs/network/ ... terns.html : pattern 3

6. Your problem: The xlite client places calls, can transmit voice, and it is heard on receiving side. But the client being called cannot transmit voice, only receive. I have tried from 2 separate computers outside of server LAN. Please help me! thank you

Are you using Brekeke PBX??
Are there any NAT/firewall between clients and SIP Server?

Have you tried the RTP-Relay at SIP Server?
If not, let you try.